- Email: [email protected]
Food and emotion
Behavioural Processes 60 (2002) 157 /164 www.elsevier.com/locate/behavproc
Food and emotion Laura Canetti a, Eytan Bachar b, Elliot M. Berry a,* a
Department of Human Nutrition and Metabolism, Hebrew University / Hadassah Medical School, Jerusalem 91120, Israel b Department of Psychiatry, Hadassah University Hospital, Jerusalem 91120, Israel Received 10 December 2001; accepted 4 March 2002
Abstract The relationship between eating and emotion has always interested researchers of human behavior. This relationship varies according to the particular characteristics of the individual and according to the specific emotional state. We consider findings on the reciprocal interactions between, on the one hand, emotions and food intake, and, on the other, the psychological and emotional consequences of losing weight and dieting. Theories on the relationship between emotions and eating behaviors have their origin in the literature on obesity. The psychosomatic theory of obesity proposes that eating may reduce anxiety, and that the obese overeat in order to reduce discomfort. The internal/external theory of obesity hypothesizes that overweight people do not recognize physiological cues of hunger or satiety because of faulty learning. It thus predicts that normal weight people will alter (either increase or decrease) their eating when stressed, while obese people will eat regardless of their physiological state. The restraint hypothesis postulates that people who chronically restrict their food intake overeat in the presence of disinhibitors such as the perception of having overeaten, alcohol or stress. These theories are examined in the light of present research and their implications on eating disorders are presented. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Eating behavior; Eating disorders; Emotion; Obesity
In their eating behavior, human beings are very much affected by their emotions: food choices, quantity and frequency of meals are all dependent on many variables not necessarily related to their physiological needs. The increasing prevalence of eating disorders and obesity in Western societies has raised many questions about the role that emotions play in the etiology of these problems. That these changes have occurred in a relatively
* Corresponding author. Fax: /972-2-643-1105 E-mail address: [email protected] (E.M. Berry).
short time frame suggests that environmental and psychological, rather than metabolic or genetic, causes are responsible. Although eating behavior has been studied in animals from a biological viewpoint, we will focus on human studies as the purpose of this article is to present eating behavior from a psychological viewpoint. It is widely accepted that the eating behavior in humans, changes according to changes in their emotional arousal (anxiety, anger, joy, depression, sadness and other emotions). However, it is not possible to make a general statement about these relationships since the relation be-
0376-6357/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved. PII: S 0 3 7 6 - 6 3 5 7 ( 0 2 ) 0 0 0 8 2 - 7
158
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
tween eating and emotion differs according to the particular characteristics of the individual and according to the specific emotional state. This paper will look first at the influence of emotions on eating behavior, then the influence of emotion on dieting and finally will discuss different theories dealing with the relationship between eating behavior and emotions and their implications for eating disorders.
because the consumed food is thought to be healthy). Thus, Macht’s study showed stronger influences of anger and joy on eating than of sadness and fear. This author suggests that anger and joy have a greater influence because these emotions are in general, more frequently experienced than sadness and fear.
2. The influence of weight loss and dieting on emotion 1. The influence of emotions on eating behavior Emotions differ in their antecedent conditions, physiological correlates, frequency of occurrence and duration (Scherer et al., 1986). The associations between a particular emotion and eating behavior should be stronger if this emotion occurs more frequently in eating contexts than other emotions (Macht and Simons, 2000). Early research paid little attention to the differential effects of different emotions. More recently a number of studies have compared various emotions, but research on their differential role characteristics is still sparse. Mehrabian (1980) investigated the relationship between different emotions and amount of food intake. He found that higher food consumption was reported during boredom, depression and fatigue and lower food intake was reported during fear, tension and pain. Lyman (1982) showed a greater tendency to consume healthy foods during positive emotions and a greater tendency to consume junk food during negative emotions. Patel and Schlundt (2001) found that meals eaten in positive and negative moods were significantly larger than meals eaten in a neutral mood and that positive mood has a stronger impact than negative moods on food intake. Macht (1999) studied the differential impact of anger, fear, sadness and joy. Subjects reported experiencing higher levels of hunger during anger and joy than during fear and sadness. They also reported that during anger there was an increase of impulsive eating (fast, irregular and careless eating directed at any food type available), and that during joy there was an increase of hedonic eating (the tendency to eat because of the pleasant taste of the food or
The classic work by Keys et al. (1950) showed that weight loss, even in normal weight men, may lead to physiologic and psychological mood changes, some of which were quite similar to those found in anorectic subjects. The famous experiment, which was carried out on conscientious objectors, showed that problems, which are considered to be characteristic of females with eating disorders, might also occur in males after considerable weight loss (mean 26%). The men complained of apathy, depression, irritability and moodiness; they also became preoccupied with food in thoughts and conversation. They collected recipes, became angry at food wastage and would toy with their meals, sometimes taking up to 2 h to complete them. Thus, weight loss per se (whether in the obese or those of normal weight) may be the common trigger, which in certain predisposed individuals precipitates an abnormal response to food and body weight. Significant weight loss may also be accompanied by persistent physical and behavioral symptoms. These include mood changes and depression, cold intolerance, hair loss, and carotenemia and ideation similar to that found in patients with anorexia nervosa, accompanied by issues of control, regimentation, compulsive exercising, and preoccupation with food and body image, even though the subjects may still be obese. Ironically an obese subject who goes from (say) 130 /100 kg may have behavioral and physiological changes similar to those in an anorexic one at 30 kg weight (Berry, 1999). Male patients who developed eating disorders after gastroplasty or bilio-pancreatic by-pass surgery, afford another example of the relationship
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
between dieting and mood changes. Bonne et al. (1996) described two morbidly obese young men who, following gastric surgery and weight losses of over 80 kg, became anorexic with intakes of less than 500 kcal/d and required psychiatric hospitalization. At the other extreme are weight-restored anorexic patients who still have problems of size over-estimation with different sensory modalities */visual, tactile and oral (Berry et al., 1995). Over 30 years ago Glucksman and Hirsch (1969) showed, using a distorting lens, that dieting may lead to a change in body image. Both weight loss and maintenance were associated with overestimation of neutral and personal shapes. The National Weight Control Registry (NWCR) in the USA has sought to characterize successful dieters who have maintained an average weight loss of 13 kg for at least 5 years. While these subjects in some studies showed no different eating disorder pathology from normal obese subjects (Klem et al., 1997), other work from the same group noted among 784 subjects that 14% had worse thoughts about food and 20% about weight, than before their dieting (Klem et al., 1998). However, it remains a moot point whether it is possible to extrapolate from these rather unique successful subjects (c5% of dieters) to the majority of unsuccessful yo-yo dieters.
3. Theories relating emotions and eating behaviors The assumption that affect and eating are related has its origins in the literature on obesity. Thus, earlier theories explained overeating in obese individuals, while more recent theories aim at explaining eating behavior in a normal weight population. The following section looks at both types of theory. 3.1. Psychosomatic theories of obesity 3.1.1. The Kaplan and Kaplan psychosomatic theory of obesity Kaplan and Kaplan (1957) proposed that obese people overeat when anxious and eating reduces this anxiety. The mechanism by which eating reduces anxiety is not completely understood but
159
may involve differential effects of protein and carbohydrate intakes affecting the synthesis of brain neurotransmitters, in particular serotonin. Learning factors are also probably involved, e.g. an earlier association of pleasurable, non-anxious situations with feeding. However, these authors felt that the anxiety-reducing effects of eating cannot be solely explained on the basis of learned habits. They hypothesized that there is some degree of physiological incompatibility between the act of eating and intense fear or anxiety and that while eating, these emotions are temporarily diminished. Obese individuals are unable to distinguish between hunger and anxiety because they learnt to eat in response to anxiety as well as in response to hunger. Thus, eating in order to reduce anxiety may lead to compulsive overeating and obesity. 3.1.2. Bruch’s theory Bruch (1973) connected overeating to faulty hunger awareness. This theory proposes that the experience of ‘hunger’ is not innate but learning is necessary for its organization into recognizable patterns. In the case of obese people something had gone wrong in the experiential and interpersonal process surrounding the satisfaction of nutritional and other bodily needs. Incorrect and confusing early experiences had interfered with their ability to recognize hunger and satiation. These early experiences had also interfered with the ability to differentiate hunger (the urge to eat), from other signals of discomfort that have nothing to do with food deprivation like emotional tension states aroused by a great variety of conflicts and problems. Such individuals do not recognize when they are hungry or satiated, nor do they differentiate need for food from other uncomfortable sensations and feelings. They require signals coming from outside to know when to eat and how much; since their own inner awareness has not been ‘programmed’ correctly (Bruch, 1973). Thus, according to this theory, a person will overeat in response to ‘emotional tension’ and ‘uncomfortable sensations and feelings’. Both Kaplan and Kaplan and Bruch’s theories reach the same prediction: that obese individuals will overeat in response to uncomfortable emotional states.
160
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
When summarizing her lifetime work in the field, Bruch (1985) who is considered a leading figure in the psychoanalytic thinking about anorexia and bulimia, pointed to self psychology as the theory which conceptualizes best her approach. Self psychology views food (its consumption in bulimia and its avoidance in anorexia) as the main stabilizing factor of dysphoric emotions and self esteem (Bachar et al., 1999). 3.2. Schachter’s ‘internal/external’ theory of obesity This theory (Schachter et al., 1968; Schachter, 1971) makes somewhat different predictions from the theories described above. Here the physiological concomitants of fear and anxiety would lead normal weight people to suppress their consumption, but would not affect obese people’s consumption due to their insensitivity to internal cues. Like Bruch (1973), he hypothesized that the recognition of a set of physiological cues, including gastric contractions, as ‘hunger’ was a learned phenomenon and that normal weight people had learned to label appropriately gastric contractions as hunger, whereas overweight people had not. Because gastric contractions decrease during stress, normal weight individuals will decrease their eating when stressed but such a decrease would have no effect on the eating of the obese. As a consequence of poor understanding of internal physiological cues, obese people will rely much more on external cues both to initiate and stop eating. While psychosomatic theories predict that obese people will increase their eating when they are stressed in order to reduce anxiety, Schachter’s theory predicts that normal weight people may either decrease or increase their eating when stressed, while obese people will not decrease it. A first study performed by Schachter et al. (1968) confirmed this prediction. They found that for normal weight subjects, stress decreased eating among those who were hungry and had no effect on those who were not hungry, while overweight subjects ate the same amount of food irrespective of their physiological state. However, later research did not replicate these previous findings
(Lowe and Fisher, 1983; Pine, 1985; Reznick and Balch, 1977; Ruderman, 1983; Slochower et al., 1981) and only one study (McKenna, 1972) confirmed Schachter’s prediction but for palatable food only. The question of whether emotions do influence eating behavior has been thoroughly studied in the obese population. These studies’ findings are closer to psychosomatic theories than to Schachter’s theory but they also shed light on the complexity of the eating behavior in obese people. A review of the field (Ganley, 1989) concluded that in massively obese subjects seeking treatment, emotional eating appears to be very common. Most studies reported a strong relationship between eating and negative emotions or stressful life events. The emotional eating occurs episodically and not on a regular basis; it is done secretively, is associated with different emotions in different individuals and is characterized by the use of high-calorie or high carbohydrate food (Ganley, 1989). Emotional eating has been found to be most frequent when people are alone, when the meal is a supper or a snack, and when the meal is eaten at home compared to away from home (Baumeister et al., 1994). Emotional eating is prevalent across the various social classes and the sexes. Studies consistently report that emotional eating is most often precipitated by negative emotions such as anger, depression, boredom, anxiety and loneliness and often bears an episodic relationship to stressful periods of life (Ganley, 1989). The impact of positive mood on food intake has not been as well studied as that of negative moods. Studies that have looked at such relationships yield conflicting results: Schmitz (1996) and Davis et al. (1985) did not find any correlation between food intake and positive moods. However Schlundt et al. (1988) found that positive mood was related to overeating in social situations. A recent study (Patel and Schlundt, 2001) showed that food intake is larger for both positive and negative moods compared to a neutral mood. These authors propose that mood effects, whether positive or negative, both involve a disinhibition of eating control. They also suggest that positive mood may increase food intake via an associative learning mechanism where happiness has been
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
associated with eating more food. These findings can be also in line with Bruch’s hypothesis that obese individuals do not differentiate need for food from emotional tension states */in this case the tension being a pleasant one. All studies reviewed were performed on obese populations and most of them found significant differences between the obese subjects and the normal weight control groups or significant weight-dependent correlations in the area of emotional eating. The conclusion that obese people engage in significantly more emotional eating compared to non-obese seems quite robust, and provides support to the psychosomatic theories. However, this conclusion has been criticized by Allison and Heshka (1993), who claim that perhaps obese persons report more emotional eating than the non-obese because they are complying with a social role. 3.3. The restraint hypothesis Investigators in the field observed that obese people are almost always trying to restrain their food intake. Thus, the question concerning eating patterns of obese people should be rephrased to the role of dieting in obese as well as normal weight individuals. The restraint hypothesis was originally developed by Herman and Mack (1975) and further elaborated by Herman and Polivy (1980). According to these researchers the balance between the desire for food and the effort to resist that desire affects eating behaviors, and restraint is the cognitive effort to resist that desire. Restrained eaters constantly worry about what they eat and chronically restrict their food intake in order to avoid becoming fat. At the other end are the unrestrained eaters who eat freely and do not worry about their food intake or its consequences. These authors also postulated a ‘disinhibition hypothesis’: according to which, self control of restrained eaters may be temporarily released by disrupting events or ‘disinhibitors’ which include specific ‘cognitions’ (the perception of having overeaten), alcohol or strong emotional states (such as anxiety and depression). A review of the literature (Ruderman, 1986) concluded that this hypothesis has been empiri-
161
cally confirmed. Most attention has focused on the assumption that the perception of having overeaten disinhibits restrained eaters. This has been manipulated by having subjects eat a pre-load before a taste test. Overall, studies show that the perception of having eaten a high calorie pre-load leads to overeating in chronically restrained eaters, who tend to think in a rigid, all-or-nothing fashion. The influence of alcohol has also been studied but results are not clear. The effects of emotional states on the consumption of restrained and unrestrained eaters have been examined. Herman and Polivy (1984) have hypothesized that strong emotions make demands on restrained eaters’ energies, thereby temporarily decreasing their motivation to diet and allowing them to overeat. Although the restraint hypothesis predicts that any strong emotion would disinhibit the restrained eaters, research has focused principally on the effects of anxiety and depression on eating (Ruderman, 1986). In their first study Herman and Polivy (1975) found, as expected, that unrestrained eaters ate significantly less in the high than in the low anxiety condition. However, restrained eaters ate slightly, but not significantly, more in the high than in the low anxiety condition. Polivy and Herman (1976) found among clinically depressed patients, that unrestrained eaters reported a significant weight loss and restrained eaters a significant weight gain after the onset of depression. Ruderman (1986) reaches the conclusion that negative affective states generally increase the consumption of restrained eaters, but their impact on unrestrained eaters is unclear: negative affect diminished consumption in the Herman and Polivy study (1975), marginally reduced it in the Baucom and Aiken study (1981) and did not significantly affect it in the Ruderman study (1985). A more recent study (Schotte et al., 1990) on negative affects induced by viewing frightening films, replicated the finding that they trigger overeating in restrained subjects. Again, in unrestrained eaters, such negative affect did not significantly affect food intake. More recently, research in the field also examined affects other than anxiety and depression and reached similar results: Cools et al. (1992) showed that exposure to a segment from an amusing comedy film disinhib-
162
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
ited eating in restrained eaters. Sheppard-Sawyer et al. (2000) tested whether film-induced sadness */ a state characterized by high negative valence, but low arousal */enhanced food intake in restrained eaters. They found that exposure to sad film segments significantly reduced food intake in unrestrained eaters, but only increased it nonsignificantly in restrained eaters. The authors hypothesized that restrained participants may not exhibit disinhibited eating when exposed to mood changes that did not threaten their self-esteem.
4. Eating disorders Although psychosomatic theories and the restraint hypothesis were related to observations of eating behavior in obese people, these theories may also explain behavior of subjects with eating disorders. The restraint hypothesis has been theoretically applied (Polivy and Herman, 1985), and empirically tested (Cooper and Bowskill, 1986; Davis et al., 1988) in these disorders. According to the restraint hypothesis, chronic dieters restrain their food intake until a disinhibitor causes a temporary break in the diet regimen with overeating. The disinhibitors might be the forced consumption of high caloric food, the intake of alcohol or experiencing tension states such as anxiety and depression. Bulimic patients and bulimic anorexics will binge eat, thus it may be that the cause of such bingeing is restraint in the intake of food prior to the development of the disorder. This assumption concerning the development of binge eating is confirmed by the observation that in most cases, bulimia develops several months after the onset of dieting (BoskindLodahl, 1976; Boskind-Lodahl and Sirlin, 1977; Garfinkel et al., 1980; Pyle et al., 1981), and by the fact that bulimics often have binge episodes after negative emotional states. For example, bulimics report more negative mood in the hour prior to a binge episode, compared with their moods prior to consuming a snack or meal (Davis et al., 1988). In another study, bulimic patients were significantly more depressed, anxious, lonely and bored in the 3 h before a binge episode, compared with baseline ratings of the 3 h after the episode (Cooper and
Bowskill, 1986). The observation that patients with bulimia nervosa almost always report that tension precipitates bulimic episodes, is also in line with the psychosomatic theories of obesity predicting that overeating reduces tension states.
5. Conclusions Emotions do influence eating behavior in human beings. Negative emotions have been thoroughly studied and it is well established that they increase food consumption. Positive emotions also increase food intake but this is less conclusive. It seems that frequent emotions such as joy and anger have a greater impact on food intake compared to less frequent ones. The above conclusions are valid for normal weight as well as overweight people. However, the influence of emotions on eating behavior is stronger in obese people than in the non-obese, and it is stronger in people on diets than in non-dieters. The conclusion that obese people engage in significantly more emotional eating than the non-obese has been confirmed empirically and is in line with the psychosomatic theories of obesity. Dieters are also more prone to emotional eating as proposed by the restraint theory. Binge eating in bulimic subjects might be understood as the undesired outcome of restrained eating.
References Allison, D.B., Heshka, S., 1993. Emotion and eating in obesity? A critical analysis. International Journal of Eating Disorders 13, 289 /295. Bachar, E., Latzer, Y., Kreitler, S., Berry, E.M., 1999. Empirical comparison of two psychological therapies: self psychology and cognitive orientation in the treatment of anorexia and bulimia. The Journal of Psychotherapy Practice and Research 8, 115 /128. Baucom, D.H., Aiken, P.A., 1981. Effect of depressed mood on eating among nonobese dieting and nondieting persons. Journal of Personality and Social Psychology 41, 577 /585. Baumeister, R.F., Heatherton, T.F., Tice, D.M., 1994. Losing Control: How and How People Fail at Self-Regulation. Academic Press, Inc, San Diego, CA. Berry, E.M., Fried, S., Edelstein, E., 1995. Abnormal oral sensory perception in patients with a history of anorexia
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164 nervosa and the relationship between physiological and psychological improvement in this disease. Psychotherapy and Psychosomatics 63, 32 /37. Berry, E.M., 1999. The reduced obese syndrome and eating disorders. In: Guy-Grand, B., Ailhaud, G. (Eds.), Progress in Obesity Research, vol. 8. John Libbey & Co, London, pp. 777 /780. Bonne, O.B., Bashi, R., Berry, E.M., 1996. Anorexia nervosa following gastroplasty in the male: two cases. International Journal of Eating Disorders 19, 105 /108. Boskind-Lodahl, M., 1976. Cinderella’s stepsisters: a feminist perspective on anorexia nervosa and bulimia. Signs: Journal of Women in Culture and Society 2, 324 /356. Boskind-Lodahl, M., Sirlin, J., 1977. The gorging-purging syndrome. Psychology Today 3, 50 /52. Bruch, H., 1973. Eating Disorders: Obesity, Anorexia Nervosa and the Person Within. Basic Books, New York. Bruch, H., 1985. Four decades of eating disorders. In: Garner, D.M., Garfinkel, P.E. (Eds.), Handbook of Psychotherapy for Anorexia Nervosa and Bulimia. Guilford Press, New York. Cools, J., Schotte, D.E., McNally, R.J., 1992. Emotional arousal and overeating in restrained eaters. Journal of Abnormal Psychology 101, 348 /351. Cooper, P.J., Bowskill, R., 1986. Dysphoric mood and overeating. British Journal of Clinical Psychology 25, 155 /156. Davis, R., Freeman, R.J., Garner, D.M., 1988. A naturalistic investigation of eating behavior in bulimia nervosa. Journal of Consulting and Clinical Psychology 56, 273 /279. Davis, R., Freeman, R.J., Solyom, L., 1985. Mood and food: an analysis of bulimic episodes. Journal of Psychiatric Research 19, 331 /335. Ganley, R.M., 1989. Emotion and eating in obesity: a review of the literature. International Journal of Eating Disorders 8, 343 /361. Garfinkel, P.E., Moldofsky, H., Garner, D.M., 1980. The heterogeneity of anorexia nervosa: bulimia as a distinct subgroup. Archives of General Psychiatry 37, 1036 /1040. Glucksman, M.L., Hirsch, J., 1969. The response of obese patients to weight reduction. Psychosomatic Medicine 31, 1 /7. Herman, C.P., Mack, D., 1975. Restrained and unrestrained eating. Journal of Personality 43, 647 /660. Herman, C.P., Polivy, J., 1975. Anxiety, restraint, and eating behavior. Journal of Abnormal Psychology 84, 666 /672. Herman, C.P., Polivy, J., 1980. Restrained eating. In: Stunkard, A.B. (Ed.), Obesity. Saunders, Philadelphia. Herman, C.P., Polivy, J., 1984. A boundary model for the regulation of eating. In: Stunkard, A.B., Stellar, E. (Eds.), Eating and its disorders. Raven Press, New York, pp. 141 / 156. Kaplan, H.I., Kaplan, H.S., 1957. The psychosomatic concept of obesity. Journal of Nervous and Mental Disease 125, 181 /201. Keys, A., Brozek, J., Henschel, A., Mickelsen, O., Taylor, H.L., 1950. The Biology of Human Starvation. University of Minnesota Press, Minneapolis.
163
Klem, M.L., Wing, R.R., McGuire, M.T., Seagle, H.M., Hill, J.O., 1997. A descriptive study of individuals successful at long-term maintenance of substantial weight loss. American Journal of Clinical Nutrition 66, 239 /246. Klem, M.L., Wing, R.R., McGuire, M.T., Seagle, H.M., Hill, J.O., 1998. Psychological symptoms in individuals successful at long-term maintenance of weight loss. Health Psychology 17, 336 /345. Lowe, M.R., Fisher, E.B., 1983. Emotional reactivity, emotional eating, and obesity: a naturalistic review. Journal of Behavioral Medicine 6, 135 /149. Lyman, B., 1982. The nutritional values and food group characteristics of food preferred during various emotions. Journal of Psychology 112, 121 /127. Macht, M., 1999. Characteristics of eating in anger, fear, sadness and joy. Appetite 33, 129 /139. Macht, M., Simons, G., 2000. Emotions and eating in everyday life. Appetite 35, 65 /71. McKenna, R.J., 1972. Some effects of anxiety level and food cues on the eating behavior of obese and normal subjects: a comparison of the Schachterian and psychosomatic conceptions. Journal of Personality and Social Psychology 22, 311 /319. Mehrabian, A., 1980. Basic Dimensions for a General Psychological Theory. Oelschlager, Gunn & Hain, Cambridge. Patel, K.A., Schlundt, D.G., 2001. Impact of moods and social context on eating behavior. Appetite 36, 111 /118. Pine, C.J., 1985. Anxiety and eating behavior in obese and nonobese American Indians and White Americans. Journal of Personality and Social Psychology 49, 774 /780. Polivy, J., Herman, C.P., 1976. Clinical depression and weight change: a complex relation. Journal of Abnormal Psychology 85, 338 /340. Polivy, J., Herman, C.P., 1985. Dieting and binging: a causal analysis. American Psychologist 40, 1193 /2201. Pyle, R.L., Mitchell, J.E., Eckert, E.D., 1981. Bulimia: a report of 34 cases. Journal of Clinical Psychiatry 42, 60 /64. Reznick, H., Balch, P., 1977. The effects of anxiety and response cost manipulations on the eating behavior of obese and normal weight subjects. Addictive Behaviors 2, 219 / 225. Ruderman, A.J., 1983. Obesity, anxiety and food consumption. Addictive Behaviors 8, 235 /242. Ruderman, A.J., 1985. Dysphoric mood and overeating: a test of restraint theory’s disinhibition hypothesis. Journal of Abnormal Psychology 94, 78 /85. Ruderman, A.J., 1986. Dietary restraint: a theoretical and empirical review. Psychological Bulletin 99, 247 /262. Schachter, S., 1971. Some extraordinary facts about obese humans and rats. American Psychologist 26, 129 /144. Schachter, S., Goldman, R., Gordon, A., 1968. Effects of fear, food deprivation and obesity on eating. Journal of Personality and Social Psychology 10, 90 /97. Scherer, K.R., Wallbott, H.G., Summerfield, A.B., 1986. Experiencing Emotion: A Crosscultural Study. Cambridge University Press, Cambridge.
164
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
Schlundt, D.G., Sbrocco, T., Bell, C., 1988. Identification of high risk situations in a behavioral weight loss program: application of the relapse model. International Journal of Obesity 13, 223 /234. Schmitz, B.A., 1996. The relationship between affect and binge eating. Dissertation Abstracts International: Section B: The Sciences and Engineering 56, 7055.
Schotte, D.E., Cools, J., McNally, R.J., 1990. Film-induced negative affect triggers overeating in restrained eaters. Journal of Abnormal Psychology 99, 317 /320. Sheppard-Sawyer, C.L., McNally, R.J., Fischer, J.H., 2000. Film-induced sadness as a trigger for disinhibited eating. International Journal of Eating Disorders 28, 215 /220. Slochower, J., Kaplan, S., Mann, L., 1981. The effects of life stress and weight on mood and eating. Appetite 2, 115 /125.
Food and emotion Laura Canetti a, Eytan Bachar b, Elliot M. Berry a,* a
Department of Human Nutrition and Metabolism, Hebrew University / Hadassah Medical School, Jerusalem 91120, Israel b Department of Psychiatry, Hadassah University Hospital, Jerusalem 91120, Israel Received 10 December 2001; accepted 4 March 2002
Abstract The relationship between eating and emotion has always interested researchers of human behavior. This relationship varies according to the particular characteristics of the individual and according to the specific emotional state. We consider findings on the reciprocal interactions between, on the one hand, emotions and food intake, and, on the other, the psychological and emotional consequences of losing weight and dieting. Theories on the relationship between emotions and eating behaviors have their origin in the literature on obesity. The psychosomatic theory of obesity proposes that eating may reduce anxiety, and that the obese overeat in order to reduce discomfort. The internal/external theory of obesity hypothesizes that overweight people do not recognize physiological cues of hunger or satiety because of faulty learning. It thus predicts that normal weight people will alter (either increase or decrease) their eating when stressed, while obese people will eat regardless of their physiological state. The restraint hypothesis postulates that people who chronically restrict their food intake overeat in the presence of disinhibitors such as the perception of having overeaten, alcohol or stress. These theories are examined in the light of present research and their implications on eating disorders are presented. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Eating behavior; Eating disorders; Emotion; Obesity
In their eating behavior, human beings are very much affected by their emotions: food choices, quantity and frequency of meals are all dependent on many variables not necessarily related to their physiological needs. The increasing prevalence of eating disorders and obesity in Western societies has raised many questions about the role that emotions play in the etiology of these problems. That these changes have occurred in a relatively
* Corresponding author. Fax: /972-2-643-1105 E-mail address: [email protected] (E.M. Berry).
short time frame suggests that environmental and psychological, rather than metabolic or genetic, causes are responsible. Although eating behavior has been studied in animals from a biological viewpoint, we will focus on human studies as the purpose of this article is to present eating behavior from a psychological viewpoint. It is widely accepted that the eating behavior in humans, changes according to changes in their emotional arousal (anxiety, anger, joy, depression, sadness and other emotions). However, it is not possible to make a general statement about these relationships since the relation be-
0376-6357/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved. PII: S 0 3 7 6 - 6 3 5 7 ( 0 2 ) 0 0 0 8 2 - 7
158
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
tween eating and emotion differs according to the particular characteristics of the individual and according to the specific emotional state. This paper will look first at the influence of emotions on eating behavior, then the influence of emotion on dieting and finally will discuss different theories dealing with the relationship between eating behavior and emotions and their implications for eating disorders.
because the consumed food is thought to be healthy). Thus, Macht’s study showed stronger influences of anger and joy on eating than of sadness and fear. This author suggests that anger and joy have a greater influence because these emotions are in general, more frequently experienced than sadness and fear.
2. The influence of weight loss and dieting on emotion 1. The influence of emotions on eating behavior Emotions differ in their antecedent conditions, physiological correlates, frequency of occurrence and duration (Scherer et al., 1986). The associations between a particular emotion and eating behavior should be stronger if this emotion occurs more frequently in eating contexts than other emotions (Macht and Simons, 2000). Early research paid little attention to the differential effects of different emotions. More recently a number of studies have compared various emotions, but research on their differential role characteristics is still sparse. Mehrabian (1980) investigated the relationship between different emotions and amount of food intake. He found that higher food consumption was reported during boredom, depression and fatigue and lower food intake was reported during fear, tension and pain. Lyman (1982) showed a greater tendency to consume healthy foods during positive emotions and a greater tendency to consume junk food during negative emotions. Patel and Schlundt (2001) found that meals eaten in positive and negative moods were significantly larger than meals eaten in a neutral mood and that positive mood has a stronger impact than negative moods on food intake. Macht (1999) studied the differential impact of anger, fear, sadness and joy. Subjects reported experiencing higher levels of hunger during anger and joy than during fear and sadness. They also reported that during anger there was an increase of impulsive eating (fast, irregular and careless eating directed at any food type available), and that during joy there was an increase of hedonic eating (the tendency to eat because of the pleasant taste of the food or
The classic work by Keys et al. (1950) showed that weight loss, even in normal weight men, may lead to physiologic and psychological mood changes, some of which were quite similar to those found in anorectic subjects. The famous experiment, which was carried out on conscientious objectors, showed that problems, which are considered to be characteristic of females with eating disorders, might also occur in males after considerable weight loss (mean 26%). The men complained of apathy, depression, irritability and moodiness; they also became preoccupied with food in thoughts and conversation. They collected recipes, became angry at food wastage and would toy with their meals, sometimes taking up to 2 h to complete them. Thus, weight loss per se (whether in the obese or those of normal weight) may be the common trigger, which in certain predisposed individuals precipitates an abnormal response to food and body weight. Significant weight loss may also be accompanied by persistent physical and behavioral symptoms. These include mood changes and depression, cold intolerance, hair loss, and carotenemia and ideation similar to that found in patients with anorexia nervosa, accompanied by issues of control, regimentation, compulsive exercising, and preoccupation with food and body image, even though the subjects may still be obese. Ironically an obese subject who goes from (say) 130 /100 kg may have behavioral and physiological changes similar to those in an anorexic one at 30 kg weight (Berry, 1999). Male patients who developed eating disorders after gastroplasty or bilio-pancreatic by-pass surgery, afford another example of the relationship
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
between dieting and mood changes. Bonne et al. (1996) described two morbidly obese young men who, following gastric surgery and weight losses of over 80 kg, became anorexic with intakes of less than 500 kcal/d and required psychiatric hospitalization. At the other extreme are weight-restored anorexic patients who still have problems of size over-estimation with different sensory modalities */visual, tactile and oral (Berry et al., 1995). Over 30 years ago Glucksman and Hirsch (1969) showed, using a distorting lens, that dieting may lead to a change in body image. Both weight loss and maintenance were associated with overestimation of neutral and personal shapes. The National Weight Control Registry (NWCR) in the USA has sought to characterize successful dieters who have maintained an average weight loss of 13 kg for at least 5 years. While these subjects in some studies showed no different eating disorder pathology from normal obese subjects (Klem et al., 1997), other work from the same group noted among 784 subjects that 14% had worse thoughts about food and 20% about weight, than before their dieting (Klem et al., 1998). However, it remains a moot point whether it is possible to extrapolate from these rather unique successful subjects (c5% of dieters) to the majority of unsuccessful yo-yo dieters.
3. Theories relating emotions and eating behaviors The assumption that affect and eating are related has its origins in the literature on obesity. Thus, earlier theories explained overeating in obese individuals, while more recent theories aim at explaining eating behavior in a normal weight population. The following section looks at both types of theory. 3.1. Psychosomatic theories of obesity 3.1.1. The Kaplan and Kaplan psychosomatic theory of obesity Kaplan and Kaplan (1957) proposed that obese people overeat when anxious and eating reduces this anxiety. The mechanism by which eating reduces anxiety is not completely understood but
159
may involve differential effects of protein and carbohydrate intakes affecting the synthesis of brain neurotransmitters, in particular serotonin. Learning factors are also probably involved, e.g. an earlier association of pleasurable, non-anxious situations with feeding. However, these authors felt that the anxiety-reducing effects of eating cannot be solely explained on the basis of learned habits. They hypothesized that there is some degree of physiological incompatibility between the act of eating and intense fear or anxiety and that while eating, these emotions are temporarily diminished. Obese individuals are unable to distinguish between hunger and anxiety because they learnt to eat in response to anxiety as well as in response to hunger. Thus, eating in order to reduce anxiety may lead to compulsive overeating and obesity. 3.1.2. Bruch’s theory Bruch (1973) connected overeating to faulty hunger awareness. This theory proposes that the experience of ‘hunger’ is not innate but learning is necessary for its organization into recognizable patterns. In the case of obese people something had gone wrong in the experiential and interpersonal process surrounding the satisfaction of nutritional and other bodily needs. Incorrect and confusing early experiences had interfered with their ability to recognize hunger and satiation. These early experiences had also interfered with the ability to differentiate hunger (the urge to eat), from other signals of discomfort that have nothing to do with food deprivation like emotional tension states aroused by a great variety of conflicts and problems. Such individuals do not recognize when they are hungry or satiated, nor do they differentiate need for food from other uncomfortable sensations and feelings. They require signals coming from outside to know when to eat and how much; since their own inner awareness has not been ‘programmed’ correctly (Bruch, 1973). Thus, according to this theory, a person will overeat in response to ‘emotional tension’ and ‘uncomfortable sensations and feelings’. Both Kaplan and Kaplan and Bruch’s theories reach the same prediction: that obese individuals will overeat in response to uncomfortable emotional states.
160
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
When summarizing her lifetime work in the field, Bruch (1985) who is considered a leading figure in the psychoanalytic thinking about anorexia and bulimia, pointed to self psychology as the theory which conceptualizes best her approach. Self psychology views food (its consumption in bulimia and its avoidance in anorexia) as the main stabilizing factor of dysphoric emotions and self esteem (Bachar et al., 1999). 3.2. Schachter’s ‘internal/external’ theory of obesity This theory (Schachter et al., 1968; Schachter, 1971) makes somewhat different predictions from the theories described above. Here the physiological concomitants of fear and anxiety would lead normal weight people to suppress their consumption, but would not affect obese people’s consumption due to their insensitivity to internal cues. Like Bruch (1973), he hypothesized that the recognition of a set of physiological cues, including gastric contractions, as ‘hunger’ was a learned phenomenon and that normal weight people had learned to label appropriately gastric contractions as hunger, whereas overweight people had not. Because gastric contractions decrease during stress, normal weight individuals will decrease their eating when stressed but such a decrease would have no effect on the eating of the obese. As a consequence of poor understanding of internal physiological cues, obese people will rely much more on external cues both to initiate and stop eating. While psychosomatic theories predict that obese people will increase their eating when they are stressed in order to reduce anxiety, Schachter’s theory predicts that normal weight people may either decrease or increase their eating when stressed, while obese people will not decrease it. A first study performed by Schachter et al. (1968) confirmed this prediction. They found that for normal weight subjects, stress decreased eating among those who were hungry and had no effect on those who were not hungry, while overweight subjects ate the same amount of food irrespective of their physiological state. However, later research did not replicate these previous findings
(Lowe and Fisher, 1983; Pine, 1985; Reznick and Balch, 1977; Ruderman, 1983; Slochower et al., 1981) and only one study (McKenna, 1972) confirmed Schachter’s prediction but for palatable food only. The question of whether emotions do influence eating behavior has been thoroughly studied in the obese population. These studies’ findings are closer to psychosomatic theories than to Schachter’s theory but they also shed light on the complexity of the eating behavior in obese people. A review of the field (Ganley, 1989) concluded that in massively obese subjects seeking treatment, emotional eating appears to be very common. Most studies reported a strong relationship between eating and negative emotions or stressful life events. The emotional eating occurs episodically and not on a regular basis; it is done secretively, is associated with different emotions in different individuals and is characterized by the use of high-calorie or high carbohydrate food (Ganley, 1989). Emotional eating has been found to be most frequent when people are alone, when the meal is a supper or a snack, and when the meal is eaten at home compared to away from home (Baumeister et al., 1994). Emotional eating is prevalent across the various social classes and the sexes. Studies consistently report that emotional eating is most often precipitated by negative emotions such as anger, depression, boredom, anxiety and loneliness and often bears an episodic relationship to stressful periods of life (Ganley, 1989). The impact of positive mood on food intake has not been as well studied as that of negative moods. Studies that have looked at such relationships yield conflicting results: Schmitz (1996) and Davis et al. (1985) did not find any correlation between food intake and positive moods. However Schlundt et al. (1988) found that positive mood was related to overeating in social situations. A recent study (Patel and Schlundt, 2001) showed that food intake is larger for both positive and negative moods compared to a neutral mood. These authors propose that mood effects, whether positive or negative, both involve a disinhibition of eating control. They also suggest that positive mood may increase food intake via an associative learning mechanism where happiness has been
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
associated with eating more food. These findings can be also in line with Bruch’s hypothesis that obese individuals do not differentiate need for food from emotional tension states */in this case the tension being a pleasant one. All studies reviewed were performed on obese populations and most of them found significant differences between the obese subjects and the normal weight control groups or significant weight-dependent correlations in the area of emotional eating. The conclusion that obese people engage in significantly more emotional eating compared to non-obese seems quite robust, and provides support to the psychosomatic theories. However, this conclusion has been criticized by Allison and Heshka (1993), who claim that perhaps obese persons report more emotional eating than the non-obese because they are complying with a social role. 3.3. The restraint hypothesis Investigators in the field observed that obese people are almost always trying to restrain their food intake. Thus, the question concerning eating patterns of obese people should be rephrased to the role of dieting in obese as well as normal weight individuals. The restraint hypothesis was originally developed by Herman and Mack (1975) and further elaborated by Herman and Polivy (1980). According to these researchers the balance between the desire for food and the effort to resist that desire affects eating behaviors, and restraint is the cognitive effort to resist that desire. Restrained eaters constantly worry about what they eat and chronically restrict their food intake in order to avoid becoming fat. At the other end are the unrestrained eaters who eat freely and do not worry about their food intake or its consequences. These authors also postulated a ‘disinhibition hypothesis’: according to which, self control of restrained eaters may be temporarily released by disrupting events or ‘disinhibitors’ which include specific ‘cognitions’ (the perception of having overeaten), alcohol or strong emotional states (such as anxiety and depression). A review of the literature (Ruderman, 1986) concluded that this hypothesis has been empiri-
161
cally confirmed. Most attention has focused on the assumption that the perception of having overeaten disinhibits restrained eaters. This has been manipulated by having subjects eat a pre-load before a taste test. Overall, studies show that the perception of having eaten a high calorie pre-load leads to overeating in chronically restrained eaters, who tend to think in a rigid, all-or-nothing fashion. The influence of alcohol has also been studied but results are not clear. The effects of emotional states on the consumption of restrained and unrestrained eaters have been examined. Herman and Polivy (1984) have hypothesized that strong emotions make demands on restrained eaters’ energies, thereby temporarily decreasing their motivation to diet and allowing them to overeat. Although the restraint hypothesis predicts that any strong emotion would disinhibit the restrained eaters, research has focused principally on the effects of anxiety and depression on eating (Ruderman, 1986). In their first study Herman and Polivy (1975) found, as expected, that unrestrained eaters ate significantly less in the high than in the low anxiety condition. However, restrained eaters ate slightly, but not significantly, more in the high than in the low anxiety condition. Polivy and Herman (1976) found among clinically depressed patients, that unrestrained eaters reported a significant weight loss and restrained eaters a significant weight gain after the onset of depression. Ruderman (1986) reaches the conclusion that negative affective states generally increase the consumption of restrained eaters, but their impact on unrestrained eaters is unclear: negative affect diminished consumption in the Herman and Polivy study (1975), marginally reduced it in the Baucom and Aiken study (1981) and did not significantly affect it in the Ruderman study (1985). A more recent study (Schotte et al., 1990) on negative affects induced by viewing frightening films, replicated the finding that they trigger overeating in restrained subjects. Again, in unrestrained eaters, such negative affect did not significantly affect food intake. More recently, research in the field also examined affects other than anxiety and depression and reached similar results: Cools et al. (1992) showed that exposure to a segment from an amusing comedy film disinhib-
162
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
ited eating in restrained eaters. Sheppard-Sawyer et al. (2000) tested whether film-induced sadness */ a state characterized by high negative valence, but low arousal */enhanced food intake in restrained eaters. They found that exposure to sad film segments significantly reduced food intake in unrestrained eaters, but only increased it nonsignificantly in restrained eaters. The authors hypothesized that restrained participants may not exhibit disinhibited eating when exposed to mood changes that did not threaten their self-esteem.
4. Eating disorders Although psychosomatic theories and the restraint hypothesis were related to observations of eating behavior in obese people, these theories may also explain behavior of subjects with eating disorders. The restraint hypothesis has been theoretically applied (Polivy and Herman, 1985), and empirically tested (Cooper and Bowskill, 1986; Davis et al., 1988) in these disorders. According to the restraint hypothesis, chronic dieters restrain their food intake until a disinhibitor causes a temporary break in the diet regimen with overeating. The disinhibitors might be the forced consumption of high caloric food, the intake of alcohol or experiencing tension states such as anxiety and depression. Bulimic patients and bulimic anorexics will binge eat, thus it may be that the cause of such bingeing is restraint in the intake of food prior to the development of the disorder. This assumption concerning the development of binge eating is confirmed by the observation that in most cases, bulimia develops several months after the onset of dieting (BoskindLodahl, 1976; Boskind-Lodahl and Sirlin, 1977; Garfinkel et al., 1980; Pyle et al., 1981), and by the fact that bulimics often have binge episodes after negative emotional states. For example, bulimics report more negative mood in the hour prior to a binge episode, compared with their moods prior to consuming a snack or meal (Davis et al., 1988). In another study, bulimic patients were significantly more depressed, anxious, lonely and bored in the 3 h before a binge episode, compared with baseline ratings of the 3 h after the episode (Cooper and
Bowskill, 1986). The observation that patients with bulimia nervosa almost always report that tension precipitates bulimic episodes, is also in line with the psychosomatic theories of obesity predicting that overeating reduces tension states.
5. Conclusions Emotions do influence eating behavior in human beings. Negative emotions have been thoroughly studied and it is well established that they increase food consumption. Positive emotions also increase food intake but this is less conclusive. It seems that frequent emotions such as joy and anger have a greater impact on food intake compared to less frequent ones. The above conclusions are valid for normal weight as well as overweight people. However, the influence of emotions on eating behavior is stronger in obese people than in the non-obese, and it is stronger in people on diets than in non-dieters. The conclusion that obese people engage in significantly more emotional eating than the non-obese has been confirmed empirically and is in line with the psychosomatic theories of obesity. Dieters are also more prone to emotional eating as proposed by the restraint theory. Binge eating in bulimic subjects might be understood as the undesired outcome of restrained eating.
References Allison, D.B., Heshka, S., 1993. Emotion and eating in obesity? A critical analysis. International Journal of Eating Disorders 13, 289 /295. Bachar, E., Latzer, Y., Kreitler, S., Berry, E.M., 1999. Empirical comparison of two psychological therapies: self psychology and cognitive orientation in the treatment of anorexia and bulimia. The Journal of Psychotherapy Practice and Research 8, 115 /128. Baucom, D.H., Aiken, P.A., 1981. Effect of depressed mood on eating among nonobese dieting and nondieting persons. Journal of Personality and Social Psychology 41, 577 /585. Baumeister, R.F., Heatherton, T.F., Tice, D.M., 1994. Losing Control: How and How People Fail at Self-Regulation. Academic Press, Inc, San Diego, CA. Berry, E.M., Fried, S., Edelstein, E., 1995. Abnormal oral sensory perception in patients with a history of anorexia
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164 nervosa and the relationship between physiological and psychological improvement in this disease. Psychotherapy and Psychosomatics 63, 32 /37. Berry, E.M., 1999. The reduced obese syndrome and eating disorders. In: Guy-Grand, B., Ailhaud, G. (Eds.), Progress in Obesity Research, vol. 8. John Libbey & Co, London, pp. 777 /780. Bonne, O.B., Bashi, R., Berry, E.M., 1996. Anorexia nervosa following gastroplasty in the male: two cases. International Journal of Eating Disorders 19, 105 /108. Boskind-Lodahl, M., 1976. Cinderella’s stepsisters: a feminist perspective on anorexia nervosa and bulimia. Signs: Journal of Women in Culture and Society 2, 324 /356. Boskind-Lodahl, M., Sirlin, J., 1977. The gorging-purging syndrome. Psychology Today 3, 50 /52. Bruch, H., 1973. Eating Disorders: Obesity, Anorexia Nervosa and the Person Within. Basic Books, New York. Bruch, H., 1985. Four decades of eating disorders. In: Garner, D.M., Garfinkel, P.E. (Eds.), Handbook of Psychotherapy for Anorexia Nervosa and Bulimia. Guilford Press, New York. Cools, J., Schotte, D.E., McNally, R.J., 1992. Emotional arousal and overeating in restrained eaters. Journal of Abnormal Psychology 101, 348 /351. Cooper, P.J., Bowskill, R., 1986. Dysphoric mood and overeating. British Journal of Clinical Psychology 25, 155 /156. Davis, R., Freeman, R.J., Garner, D.M., 1988. A naturalistic investigation of eating behavior in bulimia nervosa. Journal of Consulting and Clinical Psychology 56, 273 /279. Davis, R., Freeman, R.J., Solyom, L., 1985. Mood and food: an analysis of bulimic episodes. Journal of Psychiatric Research 19, 331 /335. Ganley, R.M., 1989. Emotion and eating in obesity: a review of the literature. International Journal of Eating Disorders 8, 343 /361. Garfinkel, P.E., Moldofsky, H., Garner, D.M., 1980. The heterogeneity of anorexia nervosa: bulimia as a distinct subgroup. Archives of General Psychiatry 37, 1036 /1040. Glucksman, M.L., Hirsch, J., 1969. The response of obese patients to weight reduction. Psychosomatic Medicine 31, 1 /7. Herman, C.P., Mack, D., 1975. Restrained and unrestrained eating. Journal of Personality 43, 647 /660. Herman, C.P., Polivy, J., 1975. Anxiety, restraint, and eating behavior. Journal of Abnormal Psychology 84, 666 /672. Herman, C.P., Polivy, J., 1980. Restrained eating. In: Stunkard, A.B. (Ed.), Obesity. Saunders, Philadelphia. Herman, C.P., Polivy, J., 1984. A boundary model for the regulation of eating. In: Stunkard, A.B., Stellar, E. (Eds.), Eating and its disorders. Raven Press, New York, pp. 141 / 156. Kaplan, H.I., Kaplan, H.S., 1957. The psychosomatic concept of obesity. Journal of Nervous and Mental Disease 125, 181 /201. Keys, A., Brozek, J., Henschel, A., Mickelsen, O., Taylor, H.L., 1950. The Biology of Human Starvation. University of Minnesota Press, Minneapolis.
163
Klem, M.L., Wing, R.R., McGuire, M.T., Seagle, H.M., Hill, J.O., 1997. A descriptive study of individuals successful at long-term maintenance of substantial weight loss. American Journal of Clinical Nutrition 66, 239 /246. Klem, M.L., Wing, R.R., McGuire, M.T., Seagle, H.M., Hill, J.O., 1998. Psychological symptoms in individuals successful at long-term maintenance of weight loss. Health Psychology 17, 336 /345. Lowe, M.R., Fisher, E.B., 1983. Emotional reactivity, emotional eating, and obesity: a naturalistic review. Journal of Behavioral Medicine 6, 135 /149. Lyman, B., 1982. The nutritional values and food group characteristics of food preferred during various emotions. Journal of Psychology 112, 121 /127. Macht, M., 1999. Characteristics of eating in anger, fear, sadness and joy. Appetite 33, 129 /139. Macht, M., Simons, G., 2000. Emotions and eating in everyday life. Appetite 35, 65 /71. McKenna, R.J., 1972. Some effects of anxiety level and food cues on the eating behavior of obese and normal subjects: a comparison of the Schachterian and psychosomatic conceptions. Journal of Personality and Social Psychology 22, 311 /319. Mehrabian, A., 1980. Basic Dimensions for a General Psychological Theory. Oelschlager, Gunn & Hain, Cambridge. Patel, K.A., Schlundt, D.G., 2001. Impact of moods and social context on eating behavior. Appetite 36, 111 /118. Pine, C.J., 1985. Anxiety and eating behavior in obese and nonobese American Indians and White Americans. Journal of Personality and Social Psychology 49, 774 /780. Polivy, J., Herman, C.P., 1976. Clinical depression and weight change: a complex relation. Journal of Abnormal Psychology 85, 338 /340. Polivy, J., Herman, C.P., 1985. Dieting and binging: a causal analysis. American Psychologist 40, 1193 /2201. Pyle, R.L., Mitchell, J.E., Eckert, E.D., 1981. Bulimia: a report of 34 cases. Journal of Clinical Psychiatry 42, 60 /64. Reznick, H., Balch, P., 1977. The effects of anxiety and response cost manipulations on the eating behavior of obese and normal weight subjects. Addictive Behaviors 2, 219 / 225. Ruderman, A.J., 1983. Obesity, anxiety and food consumption. Addictive Behaviors 8, 235 /242. Ruderman, A.J., 1985. Dysphoric mood and overeating: a test of restraint theory’s disinhibition hypothesis. Journal of Abnormal Psychology 94, 78 /85. Ruderman, A.J., 1986. Dietary restraint: a theoretical and empirical review. Psychological Bulletin 99, 247 /262. Schachter, S., 1971. Some extraordinary facts about obese humans and rats. American Psychologist 26, 129 /144. Schachter, S., Goldman, R., Gordon, A., 1968. Effects of fear, food deprivation and obesity on eating. Journal of Personality and Social Psychology 10, 90 /97. Scherer, K.R., Wallbott, H.G., Summerfield, A.B., 1986. Experiencing Emotion: A Crosscultural Study. Cambridge University Press, Cambridge.
164
L. Canetti et al. / Behavioural Processes 60 (2002) 157 /164
Schlundt, D.G., Sbrocco, T., Bell, C., 1988. Identification of high risk situations in a behavioral weight loss program: application of the relapse model. International Journal of Obesity 13, 223 /234. Schmitz, B.A., 1996. The relationship between affect and binge eating. Dissertation Abstracts International: Section B: The Sciences and Engineering 56, 7055.
Schotte, D.E., Cools, J., McNally, R.J., 1990. Film-induced negative affect triggers overeating in restrained eaters. Journal of Abnormal Psychology 99, 317 /320. Sheppard-Sawyer, C.L., McNally, R.J., Fischer, J.H., 2000. Film-induced sadness as a trigger for disinhibited eating. International Journal of Eating Disorders 28, 215 /220. Slochower, J., Kaplan, S., Mann, L., 1981. The effects of life stress and weight on mood and eating. Appetite 2, 115 /125.