Who gains or who loses weight? Psychosocial factors among first-year university students

Physiology & Behavior 96 (2009) 135–141

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Physiology & Behavior j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / p h b

Who gains or who loses weight? Psychosocial factors among first-year university students Véronique Provencher a,⁎, Janet Polivy a, Maxine Gallander Wintre b, Michael W. Pratt c, S. Mark Pancer c, Shelly Birnie-Lefcovitch d, Gerald R. Adams e a

Psychology Department, University of Toronto at Mississauga, 3359 Mississauga Rd N., Mississauga, ON, Canada L5L 1C6 Psychology Department, York University, Toronto, ON, Canada M3J 1P3 Psychology Department, Wilfrid Laurier University, Waterloo, ON, Canada N2L 3C5 d School of Social Work, Memorial University of Newfoundland, St. John's, NL, Canada A1C 5S7 e Department of Family Relations and Applied Nutrition, University of Guelph, Guelph, ON, Canada N1G 2W1 b c

a r t i c l e

i n f o

Article history: Received 3 April 2008 Received in revised form 6 September 2008 Accepted 9 September 2008 Keywords: Restrained eating Eating attitudes and behaviors Weight gain Freshmen Psychosocial influences

a b s t r a c t Self-reported weight changes over 7 months and their relation to psychosocial characteristics (self-esteem, depression, social support, perceived stress and transition perception) and eating attitudes and behaviors (restrained eating and Eating Disorder Inventory subscales [EDI]) were assessed in first-year male and female students at six Canadian universities (N = 2753). Results showed small but significant weight increases over time in males and females (M = 1.5 kg). Males who lost weight versus those who gained reported greater negative wellbeing and more negative feelings about university transition. Females who either lost or gained weight had higher initial restraint and EDI scores than did weight maintainers. At 3 months, total EDI and body dissatisfaction increased in female weight gainers compared to weight losers, plus greater drive for thinness compared to weight maintainers. Thus, males distressed at the transition from high school to university appear more likely to lose weight while well-adjusted males are more likely to gain weight. For females, however, weight gain is associated with more negative well-being and preoccupations with weight and eating. © 2008 Elsevier Inc. All rights reserved.

In developed countries, there is no doubt that the increased prevalence of obesity is a critical public health issue for all age groups [1,2]. When rates of obesity are compared between 1978–1979 and 2004 in Canada, increases from 3% to 9% in adolescents (12 to 17 year-olds), from 6% to 11% in young adults (18 to 24 year-olds) and from 14% to 23% in the general adult population (over 18 year-olds) are observed [2,3]. Obesity has been identified as a risk factor for the development of health problems such as cardiovascular diseases, hypertension, and type 2 diabetes mainly in adults [4,5], but also at younger ages (e.g. see [6,7]). In addition, obesity is perceived as a risk factor for the development of bulimia nervosa [8], with obese individuals who gain weight during childhood reporting a higher lifetime prevalence of bulimia nervosa [7]. Although many believe that modest weight loss would improve health status [9–11], the maintenance of weight loss over the long-term is quite a challenge. Even if successful weight losses are noted in the short-term, only a third of overweight/obese individuals are able to maintain their weight loss after 1 to 3 years, and this rate is even lower after 3 to 5 years [12,13]. In parallel, there are periods in life when weight gain is more likely to occur, such as postpartum weight retention observed in women

⁎ Corresponding author. Tel.: +1 905 828 3957; fax: +1 905 569 4326. E-mail address: [email protected] (V. Provencher). 0031-9384/$ – see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.physbeh.2008.09.011

after pregnancy [14]. To better prevent weight gain and reduce (or at least stabilize) the prevalence of obesity, it is important to identify and understand critical periods when the risk of gaining weight is increased. The transition from high school to college is a period of life that has been associated with weight changes [15]. When adolescents and young adults first attend college, they experience a lot of changes in their lives, such as new friends, a new school and often a new home. For some students, this transition may be difficult to make, with a wide range of distressing factors to overcome, including homesickness and friendsickness [16] as well as a sense of isolation [17]. In the popular media, the term “Freshman 15” is used to describe the idea that college students typically gain 15 lb during their first year at university. Prospective studies have shown a significant increase in body weight and body fat parameters in first-year college males and/ or females, but the mean weight gain does not necessarily reach 15 lb and instead ranges from around 2 to 4 lb [15,18–24]. It therefore appears that while significant weight gain may occur during the critical period of transition from high school to college, the increases in body weight are smaller than expected. The mean weight gain of only 2–4 lb in freshman students may reflect the fact that some students gain little or no weight and others gain more, perhaps as much as the posited 15 lb. The presence of individual differences may account at least in part for variations in

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weight changes in college freshmen. Behavioral, psychological, and social factors may determine who will be at a greater risk of gaining weight in their first year as college students. Alterations in the environment may be related to an increased susceptibility to weight gain, with changes in eating habits [15,23] and lower physical activity levels [19] observed in first-year college students who gain weight as compared to those who remain at a stable weight. In addition, restrained eating has been related to a higher vulnerability to overeating, because women with high restraint scores are more sensitive and reactive to food cues than are unrestrained eaters [25]. To our knowledge, only two studies have examined restrained eating and dieting as predictors of weight gain in college students. Restrained eaters living on campus [23] as well as females who have experienced multiple types of dieting and weight changes [21] were more likely to gain weight during the first year of college than were unrestrained, non-dieting women. Despite the fact that the transition from high school to college is a critical period for weight gain, it appears that not all first-year college males and females have the same risk. Given the challenges of adjusting to college life already facing incoming college students, and the difficulty of losing excess weight, identifying psychological/ psychosocial factors that either predispose or protect incoming college students from the added stressor of significant weight gain would be useful. The present study thus further examines these risk/ protective factors. Previous studies have mostly been conducted with small samples of students, usually from one university, and with males generally underrepresented. Additional studies are therefore needed. The main purpose of the present prospective study was to assess weight changes over time (during the first and second semester) in a large sample of first-year university males and females from 6 different Canadian universities. In addition, the relation of psychosocial characteristics to such weight changes was investigated in order to identify potential predictors and/or consequences of weight gain. We predicted that, as in recent studies [15,18–23], we would find an overall modest increase in weight during the first year of university. We further hypothesized that restrained eaters and/or weight-concerned incoming students would be more likely to gain weight, especially female restrained eaters, based on their tendency to break restraint and overeat under a variety of provocations [26]. Finally, because of major changes in students' living situations and their food environments, it was also predicted that living in university residence and attending a more rural university (where access to healthier food choices might be more limited than in a city) would both be related to weight gain. 1. Methods 1.1. Participants First-year university students in the present study had agreed to take part in a longitudinal study (with three points of data collection, i.e. summer prior to entry [T = 1], at 3 months in the first semester [T = 2], and at 7 months in the second semester [T = 3]). Participants included 2921 incoming male and female students at six Canadian universities (two large campuses in a large city [University of Toronto at St. George and York University, both in Toronto], one mid-size campus in a large city [University of Toronto at Mississauga], two midsize campuses in mid-size cities [University of Guelph and Memorial University of Newfoundland1] and one mid-size campus in a smaller 1

St. John's is thus a mid-size city (and Memorial's campus is mid-sized too). The Ontario mid-sized schools are all within an hour's drive of Toronto, and thus people there would be likely to compare themselves to the University of Toronto. Memorial, on the other hand, is the biggest school in Newfoundland or the Eastern Provinces of Canada, with Dalhousie and New Brunswick behind it in size in the medium category, and all the other schools around being in the truly small category. So people who go to Memorial see themselves as going to the big university. This perceptual bias may make Memorial seem different on some of our measures.

city [Wilfrid Laurier University]2). Therefore, these universities varied in the size of the student population, municipality size, and location (5 universities in Ontario and one university in Newfoundland and Labrador). Participants were also from different ethnic groups (NonHispanic White (69.3%), African American (3.1%), Asian/Pacific Islander (17.9%), Hispanic (2.8%), and Other or Mixed (6.2%)). 1.2. Procedures In August 2004 (cohort 1) and 2005 (cohort 2), a random sample of incoming students from the 6 participating Canadian universities was contacted by postcards before they began their first year (N = 8807 in 2004 and N = 9780 in 2005). The postcards explained the purpose of the study, including its longitudinal nature, and asked students to complete an initial questionnaire set (paper format in cohort 1 and online format in cohort 2; no meaningful differences have been observed between participants who completed their measures via paper format versus those who completed them online). Because males tend to be underrepresented in such studies and appear to be less likely to participate when invited, 50% more postcards were sent to males than to females. A total of 2921 students (N = 404 males and N = 671 females in cohort 1 and N = 890 males and N = 935 females in cohort 2), representing 15.7% of prospective participants, completed initial assessments (T = 1), which aimed to assess several psychosocial variables. In cohort 2, 21 individuals did not specify gender on the online form, so their data could not be used and they are not included in the totals above. Consent was obtained by stating in the postcard that “When we have your responses, we will take that as your permission to include your responses in our data analyses.” As a way to compensate students for participation, participants were entered into a draw for the chance to win one of six prizes of one term's tuition. Respondents from each cohort also provided follow-up data at 3 months (T = 2) and 7 months (T = 3) after the initial assessments. Of the 2921 initial participants who received the emails, 1839 (63.0% of the initial sample) completed the online questionnaire at T = 2 and 1454 (49.8% of the initial sample) did so at T = 3. A research code was used to identify participants in order to maintain confidentiality. 1.3. Measurements 1.3.1. Weight, height and BMI Participants in the study were asked to report their height and their weight, and body mass index (BMI) was calculated (kg/m2). Because weight changes over time were a main outcome of the study, only subjects with valid data with regard to weight were kept for statistical analyses. Participants who failed to report their weight status or who reported an unrealistic value (i.e. weight corresponding to a BMI lower than 14.5 kg/m2) were thus eliminated from the data sample at T =1 (N =168, yielding a total N of 2753 included in the analyses, 1253 males and 1500 females). A total of 1682 participants (702 males and 980 females) reported their weights again at T =2 and 1326 (519 males and 807 females) reported their weights at T=3. Although self-reported weight may be less accurate than measured weight [27], only minor differences were recently observed between weight changes as assessed from self-reported as opposed to measured weights, suggesting that selfreported weight is a reliable estimate of weight change over time [28]. Goodman et al. also showed that self-reported height and weight can be used in studies examining obesity and its correlates in adolescents [29]. 1.3.2. Self-esteem The Rosenberg Self-Esteem Scale (RSES) was used to measure global self-esteem in participants at T = 1 and T = 2 [30]. Self-esteem 2 What constitutes a large and a mid-size campus has been determined according to the definition provided by Statistics Canada (Center for Education Statistics, 2004–05), where a large campus has more than 500 full-time teaching staff while a medium campus has between 250 and 499 full-time teaching staff.

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refers to the person's overall evaluation of himself or his worthiness as a person [30]. The RSES is a 10-item questionnaire, which has been demonstrated to be highly reliable [31]. Cronbach's alphas for RSES in the present sample were 0.86 in August 2004 and 0.87 in August 2005. 1.3.3. Negative well-being Scales were given at three points of data collection to assess depression (Center for Epidemiologic Studies-Depression Scale, 20items [CES-D], [32]), social support (Social Provisions Scale, 24-items [SPS], [33]), and perceived stress (4-items, [34]). Each score of these three scales was summed to create a negative well-being index (reverse scores for the social support scale were used for that purpose). All these questionnaires are reliable, with Cronbach's alpha in the present sample of 0.88 and 0.90 for depression, 0.92 and 0.93 for social support and 0.72 for perceived stress in August 2004 and August 2005, respectively. 1.3.4. Transition perception To assess perceptions related to the transition from high school to university, the Transition Perception Scale [35] was completed by the participants at T = 1. On this scale, higher scores are associated with more negative feelings about entering university. Example of items from the questionnaire are “I am worried about the amount of time it will take me to adjust to being a university student” and “I feel uneasy about my relationships with others changing as a result of my going to university”. While a 5-point rating scale is used for this questionnaire, from 0 (never) to 4 (very often), a −4 (very strongly disagree) to +4 (very strongly agree) response format was used in August 2004, as it fit into the survey better at that point (this was done in consultation with the scale developer). Cronbach's alphas in the present sample were 0.74 in August 2004 and 0.78 in August 2005. 1.3.5. Attitudinal and behavioral dimensions related to eating To assess attitudinal and behavioral dimensions related to eating, students were asked to complete the Restraint Scale [36] (at T = 1 [only in the 2005 sample] and at T = 3) and several subscales of the Eating Disorders Index (EDI: drive for thinness, body dissatisfaction, bulimia and perfectionism) [37] (at T = 1 and T = 2). Validities of the Restraint Scale and the EDI have been previously reported [38,39]. Cronbach's alphas in the present sample were 0.82 for restraint in August 2005, 0.86 for the EDI subscales in August 2004 and 0.92 for the EDI subscales in August 2005. 1.3.6. Residential plans In the initial questionnaire administered at T = 1, participants indicated where they intended to live while at university. Participants were divided into two groups: residence students and commuter students. The first group, i.e. residence students, included students living alone in a university residence, living in residence with a university-assigned roommate and living with a friend or sibling in a university residence (N = 1322). The second group, i.e. commuter students, included students who resided at home with their parents (N = 1186). Students in other living arrangements (i.e. off-campus with relatives or family friends, alone in off-campus housing, with other students in a shared off-campus house or apartment, off-campus with a romantic partner, or part-time at home and part-time with relatives) were not included in these analyses (N = 236). 1.4. Statistical analyses Student t test analyses were used to assess gender differences observed at T = 1, to compare participants who completed the study at T = 3 (completers) and those who did not (non-completers), and to examine differences between participants who did or did not experienced the “Freshman 15” at T = 3. The MIXED procedure for repeated measurements, which involved repeated measures analysis

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of variance via covariance structure modeling [40], was used to assess effects of time (T = 1, T = 2 and T = 3) on weight and BMI, with alpha error inflation controlled with the Tukey–Kramer adjustment. In addition to Pearson correlational analyses between weight and psychosocial variables, one-way analyses of variance were performed to evaluate differences in psychosocial variables measured at T = 1 and at follow-ups between groups formed on the basis of weight changes at T = 3 (weight losers, maintainers, and weight gainers). When there were significant effects, Duncan's multiple comparison tests were used to determine precisely the location of significant differences. For these analyses, groups were defined as follows: weight losers are participants who lost more than 1.5 kg (i.e. the mean weight change for the group as a whole), weight maintainers are participants who kept their weight stable (±1.5 kg), and weight gainers are participants who gained more than 1.5 kg. In the next step, stepwise multiple regression analyses were conducted to identify from among the initial psychosocial variables those potentially predictive of actual weight change at T = 3 (with p-in and p-out set at 0.05). For variables not normally distributed, a log-transformation was performed. The probability level for significance used for the interpretation of all statistical analyses was set at an alpha level of p b 0.05. Because of the exploratory nature of the analyses with regards to associations between weight changes and psychosocial characteristics (we are not attempting to define a final major model within this paper), we have decided not to adjust p values for multiple comparisons. We therefore acknowledge that some findings, especially those close to a threshold of p b 0.05, could represent chance associations. 2. Results Initial characteristics of the first-year college students who participated in the study are presented in Table 1. While the mean BMI of the sample was in the normal-weight category, BMI ranged from 15.2 kg/m2 to 43.7 kg/m2 in males and from 14.5 kg/m2 to 43.2 kg/m2 in females. A gender difference was observed for BMI; males had a higher BMI at T = 1 than did females (t (2682) = 8.94; p b 0.0001). All further analyses were thus conducted separately in males and females. Initial age, BMI and psychosocial characteristics of students who completed the study at T = 3 were compared to those who did not complete the follow-up testing (i.e. completers versus non-completers). In males, lower scores for subscales of the EDI related to drive for thinness (t (1147) = 1.95; p b 0.05) and bulimia (t (1134) = 3.34; p b 0.001), and a higher score for transition perception (t (1159) = −2.85; p b 0.005) were noted in completers when compared to non-completers. In females, those who completed the study had a higher score for negative feelings regarding the transition to university (t (1424) = −3.94; p b 0.0001) than did non-completers. Subjects who completed the study therefore appear to feel more concerned about the transition from high school to university than non-completers do. This difference between completers and noncompleters should be kept in mind when interpreting results observed after T = 1.

Table 1 Descriptive characteristics of the first-year college students

Age (M ± SD; years) Weight (M ± SD; kg) BMI (M ± SD; kg/m2)a BMI categories Underweight (b18.5 kg/m2) Normal weight (18.5–25 kg/m2) Overweight (25–30 kg/m2) Obese (≥30 kg/m2) a

Male (N = 1253)

Female (N = 1500)

18.8 ± 0.8 74.2 ± 13.8 23.1 ± 3.7

17.9 ± 0.7 59.8 ± 10.8 21.9 ± 3.6

5.3% 69.7% 19.1% 5.9%

12.6% 71.5% 12.4% 3.5%

To calculate BMI, height was available in 1223 males and 1461 females.

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Fig. 1. BMI reported at each time points (T = 1, T = 2 and T = 3), in males and females. Within each gender, means with different letters are significantly different. Analyses performed in log-transformed values of BMI.

As shown in Fig. 1, significant effects of time were observed for BMI in both males and females (in males: F (2,1179) = 28.26; p b 0.0001, in females: F (2,1701) = 37.56; p b 0.0001). More specifically, BMI significantly increased between T = 1 and T = 2 (p b 0.0001 in males and females), between T = 1 and T = 3 (p b 0.0001 in males and females), and between T = 2 and T = 3 (p b 0.001 in males and p b 0.05 in females). Mean (±SD) increases in BMI correspond to weight gains of 0.9 ± 3.6 kg in males and 1.0 ± 3.0 kg in females at T = 2 and of 1.6 ± 4.4 kg in males and 1.4 ± 3.9 kg in females at T = 3. To further investigate which factors assessed at T = 1 could be related to weight changes, subjects who gained weight (more than 1.5 kg) were compared on the psychosocial variables to those who lost weight (more than 1.5 kg) or remained at a stable weight (±1.5 kg). Table 2 shows differences observed in females for age, BMI and psychosocial profile. Females who lost weight were characterized by higher weight and BMI at T = 1 when compared to those who remain at a stable weight or who gained weight. A higher initial weight was also observed in weight gainers in comparison to females who maintained their weight. No differences were observed between the female weight change groups for self-esteem, negative well-being index or feelings about transition. However, females who gained weight had higher initial scores on two EDI subscales when compared to those who remained at a stable weight, with higher scores noted on the subscales of drive for thinness and body dissatisfaction. When compared to women who maintained their weight, higher scores for restraint and EDI body dissatisfaction were also observed in females who either lost or gained weight. When restraint, EDI body dis-

Table 2 Differences observed in females for age, BMI and psychosocial variables measured at T = 1, according to weight changes categories

Age (years) Weight (kg) BMI (kg/m2) Self-esteem Negative wellbeing index⁎⁎ Transition perception EDI (total) EDI—drive for thinness EDI—body dissatisfaction EDI—bulimia EDI—perfectionism Restraint⁎⁎⁎

Weight losers (N = 113)

Weight maintainers (N = 326)

Weight gainers (N = 363)

p value

18.0 ± 0.7⁎ 64.5 ± 13.3c 23.5 ± 4.4b 71.0 ± 12.8 115.3 ± 141.3

17.9 ± 0.6 58.2 ± 9.9a 21.7 ± 3.3a 71.0 ± 10.9 106.2 ± 114.8

17.9 ± 0.7 60.4 ± 10.4b 22.0 ± 3.5a 69.7 ± 12.5 112.4 ± 128.3

0.48 b0.0001# b0.0001 0.21 0.73

37.5 ± 19.7

40.1 ± 20.7

39.9 ± 20.5

0.50

21.1 ± 14.1ab 4.2 ± 4.8ab

18.7 ± 13.9a 3.4 ± 4.5a

22.3 ± 15.2b 4.5 ± 5.0b

0.01 0.02

9.0 ± 7.5b

7.2 ± 6.7a

9.2 ± 7.2b

0.001

1.3 ± 2.1 6.3 ± 4.4 12.2 ± 6.7b

1.7 ± 3.1 6.0 ± 4.4 10.4 ± 5.6a

1.8 ± 3.3 6.4 ± 4.7 12.7 ± 6.6b

0.33 0.59 0.003

Description of weight categories: Weight losers = females who lost more than 1.5 kg; Weight maintainers = females who keep their weight stable (±1.5 kg); Weight gainers = females who gain more than 1.5 kg; ⁎: means ± SD; #: Duncan's multiple comparisons tests were used to assess differences among the three groups. Means with different letters are significantly different; ⁎⁎: negative well-being index referred to the total scores of three variables, which are depression, social support and perceived stress. ⁎⁎⁎: Restraint Scale was only administrated in cohort 2 (Weight losers: N = 61, Weight maintainers: N = 158 and Weight gainers: N = 176).

satisfaction and EDI drive for thinness were included in a regression analysis to further assess which factors were more closely related to weight change observed at T = 3, a higher level of restraint was identified as a significant predictor of an increase in weight (t = 2.36; p b 0.05). Residential plans and university attendance were also analysed for their association with weight changes. The difference in weight change between residence students and commuter students only approached significance (F (1,741) = 3.52; p = 0.06); however, weight changes were different according to the universities at which females were students (F (5,799) = 3.15; p b 0.01). More specifically, while females from the university in the mid-size, east coast city did not differ from the others, females from the mid-size, most rural school gained more weight than did females from the 3 large, ethnically diverse urban schools. In addition, females from one of the mid-size, rural schools experienced a greater weight gain than did females from the largest campus surveyed. Age, BMI and psychosocial differences observed in males are presented in Table 3. Males who lost weight had higher weight and BMI at T = 1 in comparison to males who maintained their weight. Contrary to results observed in females, no differences were observed in males for restraint and EDI scores. However, males who lost weight were characterized by more negative feelings about university transition. No differences were observed between men who gained weight and men who remained at a stable weight, with the exception of an initially higher level of self-esteem noted in weight gainers. Men who gained weight also showed a lower initial negative well-being index and less negative feelings about university transition than did men who lost weight; the two groups were similar for other initial characteristics. When self-esteem, negative well-being index and university transition perceptions were entered in a regression analysis testing potential predictors of actual weight change at T = 3, lower selfesteem and the presence of negative feelings about university transition were identified as significant determinants of a decrease in weight (t = 2.50; p b 0.05 for self-esteem, and t = −2.13; p b 0.05 for transition perception). As in females, residential plans and university attendance were also analysed as potential factors related to weight changes. When compared to commuter students, male students living in residence experienced a greater weight gain (2.0 ± 4.4 kg in residence students versus 1.1 ± 4.5 kg in commuter students (F (1,468) = 4.96; p b 0.05). No significant differences in weight changes were observed when a comparison among universities was computed (F (5,512) = 1.88; p = 0.10). To assess whether weight changes were related to psychosocial characteristics measured at the follow-up periods, correlational analyses were initially conducted. While no associations were

Table 3 Differences observed in males for age, BMI and psychosocial variables measured at T = 1, according to weight changes categories Weight losers Weight maintainers Weight gainers p value (N = 89) (N = 180) (N = 249) Age (years) 18.1 ± 1.2⁎ Weight (kg) 77.0 ± 17.7b BMI (kg/m2) 23.9 ± 4.6b Self-esteem 70.9 ± 12.2ab Negative well-being 120.2 ± 113.2b index⁎⁎ Transition perception 40.0 ± 20.4b EDI (total) 15.1 ± 11.5 Restraint 8.9 ± 5.8

17.9 ± 0.7 71.9 ± 13.5a 22.6 ± 3.7a 70.6 ± 13.2a 91.5 ± 116.6a

18.0 ± 0.7 74.6 ± 12.7ab 23.2 ± 3.4ab 73.5 ± 11.5b 83.9 ± 108.3a

0.14 0.01# 0.02 0.03 0.03

33.6 ± 18.4a 12.3 ± 9.1 7.1 ± 4.8

32.6 ± 19.0a 13.0 ± 9.8 8.7 ± 6.0

0.007 0.24 0.05

Description of weight categories: Weight losers = males who lost more than 1.5 kg; Weight maintainers = males who keep their weight stable (± 1.5 kg); Weight gainers = males who gain more than 1.5 kg; ⁎: means ± SD; #: Duncan's multiple comparisons tests were used to assess differences among the three groups. Means with different letters are significantly different; ⁎⁎: negative well-being index referred to the total scores of three variables, which are depression, social support and perceived stress. ⁎⁎⁎: Restraint Scale was only administrated in cohort 2 (Weight losers: N = 44, Weight maintainers: N = 109 and Weight gainers: N = 154).

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observed in males, increase in body weight at T = 2 in females was related to increases in the negative well-being index (r = 0.11; p b 0.001) and total EDI (r = 0.18; p b 0.0001) as well as to decrease in self-esteem (r = − 0.09; p b 0.01). No significant associations were observed between weight changes and psychosocial factors at T = 3, in either males or females. When analyses were conducted between groups formed on the basis of weight changes at T = 3, females who gained weight experienced greater increases in total EDI and body dissatisfaction at T = 2 than did those who lost weight (F (2,705) = 4.61; p b 0.01 and F (2,705) = 5.31; p b 0.01, respectively). Female weight gainers also experienced a larger increase in drive for thinness at T = 2 when compared to weight maintainers (F (2,706) = 4.00; p b 0.05). Following a regression analysis, a greater increase in total EDI at T = 2 was identified as a significant predictor of an increase in weight during the same period (t = 4.82; p b 0.0001). Again in males, no differences in psychosocial factors at T = 2 or T = 3 were observed between weight losers, weight maintainers and weight gainers. Further analyses were also conducted to verify whether some participants did gain more than 15 lb at T = 3, i.e., if some of them experienced the “Freshman 15”. At T = 3, 8.8% of the sample (N = 61 males and N = 56 females) had gained more than 6.8 kg (15 lbs) since T = 1. When age, BMI and psychosocial variables were compared between students who were categorized as “Freshman 15” and those who did not experienced this weight gain, “Freshman 15” females had an initially higher BMI (t (57.3) = −3.98; p b 0.001) as well as higher total EDI (t (787) = −2.30; p b 0.05), drive for thinness (t (788) = −2.19; p b 0.05), body dissatisfaction (t (787) = −2.04; p b 0.05) and restraint (t (393) = − 3.05; p b 0.01) scores than did females who did not experience such a large weight gain. In males, those who were categorized as “Freshman 15” had higher self-esteem scores (t (93.8) = − 3.49; p b 0.001) and less negative feelings about transition to university (t (507) = 2.15; p b 0.05) (a tendency was also observed for a lower negative well-being index, with t (504) = 1.63; p = 0.10). Finally, to verify whether prior differences observed in male and female weight gainers actually represent only those who truly gain as much as 15 lb, analyses were re-conducted without the subgroup who gained 15 lb or more. The pattern of results remains the same for males and females when those who experienced the “Freshman 15” were removed, so it was not just the individuals who gained a lot of weight who were responsible for the effects observed. 3. Discussion The main purposes of the present study were to assess and quantify weight changes observed in a large sample of males and females, during the first year at university as well as to investigate whether weight changes are related to psychosocial characteristics measured over the same time period. Results observed in the present sample showed that a small but significant weight gain was observed during the period of transition from high school to university in students overall, and that the mythical “Freshman 15” was noted in a small percentage of first-year university students. Moreover, different psychosocial factors were identified as predictors of weight changes, particularly of the full “Freshman 15”, in females from those observed in males. In accordance with previous studies [15,18–24], significant increases in weight and BMI were observed over time in both males and females. The mean weight gain noted at the end of the first year (i.e. 1.6 ± 4.4 kg in males and 1.4 ± 3.9 kg in females) was modest and far from the popular “Freshman 15” notion, but is actually consistent with the current literature (see e.g. [22]). Transition from high school to university thus does appear to be a significant period of life with respect to weight gain; moreover, psychosocial factors seem to determine who will be at greater risk of weight change at this time. When compared to females who maintained their weight, females who either lost or gained weight showed higher restraint and EDI

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scores, particularly for the EDI subscale related to body dissatisfaction. The fact that few restrained eaters actually lost weight (N = 23), but many more gained it (N = 110) indicates that in restrained females, psychosocial difficulties are much more likely to be associated with weight gain than weight loss. These observations were further supported by the regression analysis which identified a higher level of restraint at T = 1 as a significant predictor of an increase in weight over time. In addition, weight gain over time in females was associated with increases in total EDI, body dissatisfaction and drive for thinness at T = 2, with a greater increase in total EDI at T = 2 identified as a predictor of a further increase in weight at T = 3. These findings suggest that females who gained weight started out as more likely to be dieters/restrained eaters, and their eating attitudes and behaviors got more pathological over time. Vulnerability to weight gain in first-year university females thus appears to be associated with preoccupations about weight and eating rather than with negative well-being and concerns about the transition from high school to university. Results from the present study are supported by the previous literature on the effects of restrained eating on overeating [25,41,42] and risk of weight gain [43–45] in young females. It could also be suggested that females who gained weight may be at a greater risk for developing more serious eating disorder symptoms as a consequence of their increasingly unhealthy attitudes toward eating and weight. In fact, these young females could be caught in a false-hope cycle such that initial EDI body dissatisfaction and high restraint promote dieting in order to close the discrepancy between these negative attitudes and perceived overweight. However, when the diet fails or the female experiences weight gain, these negative attitudes worsen and thus, she could be more likely to attempt to remedy this failed diet/weight gain with another diet, beginning the cycle again [46]. Examination of weight change categories in males revealed different patterns of associations from those observed in females. Whereas there were no differences in psychological variables related to eating between males who lost, gained, or maintained their weight, significant differences in well-being measures were noted. Males who lost weight had a higher negative well-being index and more negative feelings about transition than did males who gained weight. Psychological variables related to lower levels of well-being before entering university were also significant predictors of weight decreases in males after 7 months in university. However, no relationships were found for males between weight changes and psychosocial characteristics measured at the 2 follow-up periods. Results from the present study therefore suggest that weight loss occurring in first-year university males may be a negative outcome, associated with difficulties experienced during the transition from high school to university. Male weight gainers, on the other hand, were characterized by more positive psychological well-being at T = 1. Although it may appear surprising that weight gain was associated with positive affect, it is important to remember that most males who gained weight had a mean BMI within the normal-weight range both initially and after they gained weight. In addition, having a higher BMI could be related to gains in muscle mass, strength and fitness, which are perceived as positive outcomes for males [47]. With regards to the different patterns of associations observed between males and females, these results could be partly explained by the fact that while males' self-esteem increases between ages 14 and 23, females' self-esteem tends to decrease over that same time period [48]. Social factors were also analysed for their association with weight changes in males and females. Male students living in residence experienced greater weight gain than did male commuter students, although the same pattern was only marginally significant for females. On the other hand, while no differences were observed based on the particular university attended by males, females from the relatively small, rural schools studied here gained more weight than did females from the large, urban campuses in this study. Interestingly, the majority of females from the two smallest schools were living on

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campus while the majority of females from the three largest campuses were living at home with their parents. It has been previously shown that students living on campus are more prone to gain weight than are those still living with their parents [23]. Levitsky et al. [15] suggested that environmental stimuli that characterize campus residence, such as “all-you-can-eat” dining halls, could partly explain the weight gain observed in Cornell students, who mostly live on campus. In addition, living away from a home setting requires that the student take responsibility for his or her own meals, which may lead to increased consumption of prepared meals, snacks and fast foods (less nutritious meals) and less “home cooking”. With regards to university attendance, it may be that a university located in a big city could both provide more restaurants and healthy meal options, and also entail more commuting and home (meal) visits than universities located in smaller communities, for which a higher rate of living on campus is noted. Additionally, other psychosocial factors such as university group affiliations (e.g., Greek affiliation), increased drinking opportunities at school, or coping styles could be examined as potential predictors of weight change in first-year students. With regards to the myth of the “Freshman 15”, results from the current study showed that about 9% of the sample of first-year university students (11.8% of males and 7% of females) did experience a weight gain of more than 15 lb over their first year of university. Psychosocial variables at T = 1 were also identified as potential predictors of weight gain, with those who did experience the “Freshman 15” looking very different if they were males versus females. Males who are more distressed at the transition from high school to university appear more likely to lose weight while welladjusted males are more likely to gain weight and to experience the “Freshman 15”. In females however, those who gained 15 lb were characterized by more preoccupations with weight and eating. In accordance with results previously discussed, preoccupations about weight and eating appear to be consistent risk factors for weight gain in first-year university females and should thus be further considered in weight-management interventions. In addition to the high attrition rate observed over time, the main limitations of this study were that the data on weight and height were self-reported and no data were collected on body fat parameters, dietary intake or physical activity levels. Information about actual eating and exercise habits might contribute to better understanding of factors related to weight changes in students during their transition from high school to university. We acknowledge that small to moderate magnitude of change was observed for most of the significant differences reported. Because this study was conducted in natural settings as an exploratory investigation of psychosocial correlates of weight changes, uncontrolled external factors may have had an impact on the size of the effects observed. The present study had a large sample size, and included both male and female students from several different universities, communities, and ethnicities. These characteristics, as well as the assessments of psychosocial characteristics, were all strengths of the present study, and enhance its generalizability. Additional studies are nonetheless still needed to fully investigate the sex differences in psychosocial predictors of weight change in first-year university students observed in the present study. 4. Conclusions Findings from the present study suggest that although a small but significant weight gain was observed in the overall sample during the first year at university (dispelling yet again the myth of the Freshman 15, except for approximately 9% of the sample), individual students vary in their degree of risk of weight gain. Different psychosocial factors were identified as predictors of weight changes for males and females. Females who entered university with more negative eating attitudes, body dissatisfaction, and dieting behaviors were more likely

to gain weight during their first year (and, for some of them, to experience a real “Freshman 15”). In addition, these eating-related dimensions get worse over time for females who gain weight. None of these eating-related effects was observed in males, who were more likely to gain weight if they were normal weight and had higher levels of well-being. Weight gain for these normal-weight males thus appeared to be a more positive event than weight gain for females, and weight loss in males was associated with more negative feelings about the transition to university. The transition from high school to university is thus an informative period for weight gain, but in different ways for males and females. Acknowledgements This research project was supported by a grant from the Social Sciences and Humanities Research Council. V.P. is a recipient of fellowships from the Canadian Institutes of Health Research and Canadian Diabetes Association. 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