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Intermittent low-calorie regimen and booster sessions in the treatment of obesity
Behac. Res. Thu. Vol. 22, No. 4, pp. 445-449. Printed in Great Britdn. All nghts reserved
Intermittent
1984 Copyright
OOOS-7967/84 $3.00 + 0.00 Q 1984 Pergamon Press Ltd
low-calorie regimen and booster sessions in the treatment of obesity
RENA R. WING,* LEONARD H. EPSTEIN, MARSHA D. MARCUS and RANDI KOEXE Weslern Psvchiatric Insiitule and Clinic, University of Pittsburgh School of Medicine, 3811 O’Hara Street, Piusburgh, PA 15213, U.S.A. (Received 21 September
1983)
Summary-The present study investigated two new weight-control strategies: an intermittent low-calorie regimen and intermittent scheduling of booster sessions. A new approach to predicting patient weight loss, based on a pretreatment assessment with a highly-structured eating regimen, was also studied. Forty-eight obese patients were randomly assigned to either a Standard Behavioral weight-control condition or to an Intermittent Low-calorie Regimen ( < 750 cal for 2 days/week) condition and to one of two maintenance schedules: a Spaced schedule in which the six booster sessions were held at monthly intervals, or a Massed schedule, in which four of the six meetings were held during the third month. Neither the intermittent low-calorie regimen nor the intermittent scheduling of booster sessions significantly affected weight loss. However, weight loss at 1 year was related to compliance to self-monitoring and to self-reported change in eating habits and exercise. In addition, weight loss at 1 year was related to weight loss during the initial pretreatment assessment period.
INTRODUCTION Weight losses achieved in behavioral treatment programs are usually modest, averaging 10-20 lb (Foreyt, Mitchell, Gamer, Gee, Scott and Gotto, 1982; Jeffery, Wing and Stunkard, 1978b). These losses are maintained, but not extended during the year after treatment (Wilson and Brownell, 1980: Wing and Jeffery, 1979). Efforts to improve the results of behavioral weight-control programs fall into two basic categories: (a) efforts to increase the rate of weight loss during the initial treatment period; and (b) efforts to increase the length of time during which behavior changes are maintained, and consequently the length of time during which weight loss takes place. Various strategies have been used to increase the rate of initial weight loss. These include the use of anorectic medication (Craighead, Stunkard and O’Brien, 1981), contingency contracting procedures (Jeffery, Thompson and Wing, 1978a; Jeffery, Gerber, Rosenthal and Lindquist, 1983) and more stringent dietary modification (Lindner and Blackburn, 1976; Wing, Epstein and Shapira, 1982). The drugs, contracts or diets are prescribed during the initial weeks of therapy, and discontinued later in the program. Although weight losses are increased while the procedures are in effect, differences in long-term weight losses are usually not observed. The second approach to improving weight loss is to increase the period of time during which behavior changes are maintained. Techniques designed to accomplish this include spouse support (Brownell, Heckerman, Westlake, Hayes and Monti, 1978), relapse-prevention strategies (Marlatt and Gordon, 1979) and booster sessions (Ashby and Wilson, 1977). Booster sessions are typically held at monthly or at gradually increasing intervals to fade the degree of therapist contact. As used, booster sessions have had mixed effects on long-term weight loss (Wilson and Brownell, 1980). In the present study, it was hypothesized that weight losses might be improved by alternating periods of tight behavior control with periods of looser control. This was accomplished through the use of two specific strategies: an intermittent low-calorie regimen and intermittent scheduling of booster sessions. Clausen, Silfen, Coombs, Ayers and Altschul (1980) reported that patients who alternated between a structured, very low-calorie diet ( < 750 cal) for several days a week and a more moderate calorie goal ( 2 1200 cal) on the other days, lost significantly more weight (R = 20.7 lb) than those who remained at the moderate calorie goal throughout (Z? = 10.0 lb). This type of intermittent low-calorie regimen has the advantage that it could be maintained indefinitely, rather than being used initially and subsequently discontinued, However, since patients in the Clausen et al. (1980) study had selected which type of diet to follow, a more controlled test of the intermittent low-calorie regimen was needed. Secondly, a new schedule of booster sessions was investigated. Since previous studies have suggested that patients maintain their behavior changes for the first 3 months after therapy, and then experience relapse {Hunt, Bamett and Branch, 1971), a 3-month period of no booster sessions was followed by a period of frequent booster contacts with weekly meetings for 1 month, and then infrequent contact during the remainder of the l-year follow-up period. It was hypothesized that patients would maintain their weight losses during the 3-month hiatus and then lose additional weight during the month of intense contact, which would be maintained at follow-up. The present study also included a new approach to predicting Ss’ weight loss. Ss were asked to participate in a IO-day pretreatment assessment period, which included several days on a highly-structured, low-calorie eating plan. Weight loss during the pretreatment assessment period was used to predict patients’ weight loss during the subsequent program and overall. METHOD Subjecrs
Newspaper articles and physician referrals were used to recruit patients to participate in the present study. To be eligible, patients had to be aged 20-65, > 20:s overweight, not currently involved in any other weight-control programs and willing *To whom all reprint requests should be addressed. 445
446
CASE
HISTORIES
AND SHORTER
CO.MMUNICATIONS
to participate in a 15-month study. An $85.00 deposit was required: S35.00 was non-refundable; $50.00 was refunded for attendance at treatment and follow-up meetings. Those individuals who were interested in the program were invited to an orientation meeting,at which time the &tail\ of the Program were explained. Ninety-four persons attended the orientation meeting, 17 of these did not meet the entry criteria, and 29 either chose not to enter the study or did not complete the pretreatment assessment period. The remaining 48 Ss (42 females; 6 males) were randomly assigned to a treatment condition. The average weight at entry (mean + SEM) was 203.55 k 5.06 lb (range 139-287 lb). Body mass index (wtiht? averaged 36.45. .S s ranged in age from 20-63. averaging 44.79 f 1.56 years of age. Pretreatment
assessment
All Ss were asked to participate in a IO-day assessment procedure. Ss recorded their intake and physical activity for the 4 days following the orientation meeting. They were instructed to try to maintain their normal pattern of intake and expenditure during this time. For Days 5-7, Ss were given an individually prescribed diet consisting of only Slender breakfast bars (137 Cal/bar) and liquid Slender in cans (225 Cal/can). A calorie goal was calculated for each S (based on present weight x 12 - 1000 cal) and the combination of bars and cans that would most closely achieve this goal was prescribed. For Days 8-10, Ss were instructed to return to regular foods. but to maintam their intake at or below the prescribed calorie goal. Ss were weighed at the orientation meeting, and again on Days 4. 7 and 10 of the screening period. All weigh-ins were held at the same time of the evening. Treatment Subjects who completed the pretreatment assessments were randomly assigned to one of two treatment conditions: Intermittent Low-calorie Regimen or Standard Behavioral condition. Clients in both condittons attended weekly meetings for a lo-week period. Each meeting lasted 60-90 min and consisted of an individual weigh-in, review and collection of food diaries and presentation of a new lesson. Lessons covered energy balance, strategies for increasing exercise, stimulus control. cognitive restructuring, self-reinforcement and relapse prevention. The two treatment conditions differed only in the type of eating plan that was prescribed. Ss in the Standard Behavioral condition were given a calorie goal (based on initial weight x I 2 - 1000 cal). They were told to self-monitor their caloric intake and to stay within the calorie goal. All Ss were given calorie goals of at least lOOOcal/day. Subjects in the Intermittent Low-calorie Regimen were given comparable individualized goals to follow for 5 days/week. For the other 2 days of the week, Ss were advised to practice ‘self-control’ by restricting intake to below 750 Cal/day. Ss were given two specific plans for achieving the low-calorie goal: they could either follow a prescribed low-calorie menu or could return to a combination of liquid Slender and Slender bars. It was explained to Ss that both of these eating plans would simplify the decisions involved with meal selection and would help reduce the stimuli associated with overeating. At the weekly treatment meeting, Ss selected the 2 self-control days for the followmg week, and could thus tailor the self-control days to fit their individual life-style. Booster
sessions
Two schedules of booster sessions were compared (Spaced/Massed). Half of the Ss from each treatment condition were assigned to the Spaced Booster schedule and half to the Massed Booster schedule. To ensure that patients who had been successful during initial treatment were evenly distributed in the two booster schedules, Ss were blocked according to weight loss during the lo-week program (lost < IO lb; lost IO-20 lb; lost > 20 lb) and randomly assigned from within blocks to one of the two booster contact schedules. During follow-up patients were seen m four separate groups, formed from the two treatment conditions (Intermittent Low-calorie/Standard Behavioral) and two booster schedules (Spaced/Massed). Each of the four groups met six times during the 6 months following initial treatment. For the Spaced Booster condition. the six meetings were held at monthly intervals over the 6-month period (Weeks 4. 8. 12. 16. 20 and 24 of the follow-up period). The Massed Booster condition met once at the beginning and once at the end of the 6-month maintenance interval. but their remaining four meetings were massed during the third month of the maintenance interval. The Massed Booster condition met on Weeks 4, 13, 14, 15, 16 and 24 of the follow-up interval. Both conditions were seen again 12 months after initial treatment. The content of the booster sessions was similar for the two conditions. Clients were taught to use problem-solving techniques to identify difficult situations and preplan strategies for coping with these situations. Additional topics related to nutrition and exercise were discussed, such as low-calorie food preparation and exercising in cold weather. Dependent
measures
The nrimarv dependent measure was weight loss, which was measured at each meeting throughout the program. Self-monitori& records were used to assess compliance to the treatment program. To determine whether there were changes in eating habits, Ss completed the Eating Behavior Inventory (EBI; O’Neill, Currey. Hirsch, Malcolm. Sexauer. Riddle and Taylor, 1979) at the start and end of treatment and at 6-month follow-up. A cupboard survey identifying the number of high-, medium- and low-calorie foods currently found in the house was completed before and after the treatment. RESULTS Weight -loss dota Forty-six of the 48 Ss completed the IO-week treatment period. The 2 dropouts (one from each condition) were assumed to have lost no weight. The average weights for all 48 Ss at various points m the IO-week treatment period are presented in Table 1. No significant differences between conditions were observed for weight at the start of the program. Weight loss averaged 3.8 lb during the IO-day pretreatment period and was not slgmficantly different for clients in the two conditions. A repeated-measures analysis of variance was computed to compare the weight loss of the two conditions over the lo-week treatment period. Condition (Intermittent Low-calorie/Standard Behavioral) was used as a between-group factor and time (Weeks I, 5, 10) was used as a repeated measure. Only the effect of time was significant [F(2.92) = 87.35, P < O.OOI]. Clients m the Standard Behavioral condition lost II.71 lb during the IO-week treatment. compared to 14.33 lb for clients in the Intermittent Low-calorie condition. The total weight loss from pretreatment to the end of the IO-week program was 16.24 lb for clients in the Standard Behavioral condition and 17.47 lb for those in the Intermittent Low-calorie condition.
CASE
Table
1. Weight
HISTORIES
AND
SHORTFJR
COMMUNICATIONS
(lb) for Intermittent Low-calorie Regimen and during the IO-week treatment period
change
Standard Behavioral conditions
Treatment Intermittent Lowtaloiie (N = 25) R
Time period Pretreatment weight Weight loss pretreatment Welght loss pretreatment Weight loss pretreatment
to week to week IO
condition
SEM
202.42 + 6.09 - 3.14 * 0.55 - 11.17+0.99 - 17.47 f 1.97
5
week 10
Standard
Behavioral (N = 23) JJ SEM 204.78 - 4.53 - 10.26 - 16.24
i f f +
8.37 0.66 1.50 2.01
The 46 clients who completed the treatment period were blocked according to weight loss and randomly assigned from within blocks to one of the two maintenance strategies. Forty-four of the 46 clients completed the maintenance phase. Table 2 presents the weight changes experienced by these 44 patients during the various phases of treatment. A 2 x 2 analysis of variance, comparing the weight changes of the two treatments (Intermittent Low-calorie/Standard Behavioral) and two maintenance conditions (Spaced/Massed) during the year following treatment (posttreatment to 6 months/6 months to 12 months) was computed. Once again, the only significant effect was for time [F(2,80) = 67.66, P < O.OOl].Clients regained substantial amounts of weight during the year following initial treatment, (8 = 11.70 + 1.88 lb, mean + SEM). There was no significant difference in the amount regained for clients in the Spaced vs Massed Booster sessions. Further, clients in the Massed Booster session lost only an average of 0.45 lb during the month of weekly follow-up meetings. Adherence
To determine whether the lack of difference in weight loss for clients in the Intermittent Low-calorie Regimen and those in the Standard Behavioral condition resulted from the failure to comply with the low-calorie diet, the daily self-report diaries were checked to determine the number of days on which clients reported eating c 750 cai and the number of weeks in which there were 2 or more low-calorie days ( < 750 Cal). Clients in the Intermittent Low-calorie Regimen reported eating < 750 cal on an average of 13.4 + 1.7 days during the IO-week program. This was significantly more than the 5.9 + 1.2 days of low-calorie eating observed in the Standard Behavioral condition [F(1,46) = 12.84, P -z O.OOl].In addition, clients in the Intermittent Low-calorie condition reported eating < 750 cal for 2 days/week during 4.4 + 0.5 weeks of the program, compared to 1.2 f 0.3 weeks for the Standard Behavioral condition [F(1,46) = 28.49, P < O.OOl].These data suggest that the low-calorie days were followed fairly well by clients. However, in spite of compliance to the low-calorie days, the total intake for clients in the Intermittent Low-calorie Regimen (1106.1 + 5O.Ocal) was not significantly different from that of the Standard Behavioral condition (1199.1k 84.0 Cal). To determine whether adhering to low-calorie days resulted in lower overall intake or improved weight loss, the total sample was divided into two groups according to the frequency of self-reported intake below 75Ocal. Those clients who frequently ate less than 750 cal had lower total caloric intake [f(45) = 3.12, P < 0.011 and greater weight losses during treatment [r(46) = 2.23, P < 0.051 than those clients who rarely ate below 750 cal. However, an even stronger predictor of weight loss was the number of weeks in which the client self-recorded intake. Ss were divided into two groups based on the number of weeks in which they had self-recorded their intake for 5 days or more. Those Ss who were more compliant with self-monitoring lost more weight during the IO-week treatment period [ - 18.09 vs - 7.15 lb; r(46) = 5.14, P < O.OOl]. In addition, the total weight loss. from pretreatment to l-year follow-up, was - 10.8 lb for those who were above the median in compliance to self-monitoring. compared to a 3.10 lb weight gain for those who were below the median in compliance to self-monitoring (1(46) = 2.97, P <: 0.011. Behaoior change
Significant improvements in eating habits, as assessed by the EBI, were observed at the end of the IO-week treatment [F(1,40) = 71.86. P < O.OOl]and at the 6-month follow-up [F(1,35) = 27.72, P < O.OOl]. The EBI was not readministered at I year. The 23 clients who completed the cupboard survey also reported significant reductions in the number of high-calorie foods stored in the home [F(1.21) = 9.75, P < 0.011 over the course of the IO-week program.
Table 2. Weight
changes
(lb) for each treatment
and maintenance
intermittent Low-calorie condition Tune period Pre-post R SEM Post-6 months .v SEM 6 Months-12 months R SEM Total (pre-12 K SEM
condition
Standard Behavioral condition
Massed (N = 11)
Spaced (N = 12)
Massed (N = 12)
Spaced (N = 9)
- 19.46 5 3.19
- 17.59 + 2.49
- 16.13 + 2.16
- 18.86 + 3.84
+ 7.41 -+ 4.36
+ 11.58 _t 3.17
+ 8.38 + 2.91
+ 7.45 f 4.03
+4.61 2 1.86
+ 1.56 i 2.32
+ 4.06 * 3.07
+ 0.97 + 4.42
- 7.43 t 5.67
- 4.44 + 4.44
- 3.69 + 2.43
- 10.44 + 5.18
months)
Weight loss from pretreatment to I-year follow-up was correlated with changes on the EBI at the end of treatment (r = 0.41, P < 0.01) and at 6 months (r = 0.61, P < O.OOl),and with reductions in the total number of foods stored in the home (r = 0.50, P c 0.01). In addition, weight loss was significantly correlated with self-reported caloric expenditure at I year (r = 0.50, P < 0.01). Significant correlations were also found between total weight lass and use of the following behavioral strategies: use of eating diaries (r = 0.46, P “E:O.OOl),frequent weighing (r = 0.49. P < 0.001). graphing weight {r = 0.38, P c 0.05) and increasing exercise fr = 0.45, P c O.OOl).
Prior to the program, patients were asked to self-monitor their usuaf caloric intake and exercise for 4 days. Weight loss during this period was minimal (kT *t 0.18 + 0.4 lb). During the subsequent 3 days of pretreatment assessment. when patients were asked to restrict their intake to Slender and to reduce their estimated baseline intake by 1000 cal, there was an average weight loss of 2.8 + 0.3 lb. Patients then returned to regular food but remained at the lower level of caloric intake. An additional 1 lb weigh& loss occurred during this final 3-day period. Overall weight loss, during the 10 days of preassessment. averaged 3.8 I lb and ranged from - t 1.75to + 1.0 lb. Weight loss over the full pretreatment assessment period and during each phase of the assessment was unrelated to subsequenr weight Ibss. However, the weight loss achieved during the preassessment period was correlated with foral weight loss during treatment (I = 0.34, P < 0.05) and over the entire l-year period (r = 0.39, P < 0.01). DlSCUSSION
In the present study, no significant dif&erences in weight loss were observed between clients who were prescribed an inte~ittent low-calorie regimen and those who followed a more moderate calorie regimen throughout. Further, the schedule of booster sessions was not signiticantly related to long-term results. Clients who were seen weekly for a 4-week period during the year of folfow-up lost only 0.5 lb during the month of intense contact and were not significantly different at 6-month or l-year follow-ups from those who were Seen at monthly intervals. The finding that the intermittent low-calorie regimen did not increase weight loss over the standard regimen may be due to the fact that the intermittent low-calorie regimen did not produce a greater reduction in overall caloric intake, as judged from clients’ self-report diaries, than occurred in the more moderate regimen. Two previous studies by Wing et ul. ( 1982; Wing and Epstein, 1981) have likewise failed to show a significant effect of dietary prescription on weight loss. Wing and Epstein (198lf instructed clients to reduce their caloric intake by either small, moderate or large amounts during the initial 5 weeks of a therapy program. This manipulation did not afIect initiai or subsequent weight loss. Aithough clients were prescribed different degrees of caloric restriction, once again their self-reported intake was not significantly different by condition. The use of the Scarsdale Medical Diet at the outset of a behaviorai weight-control program increased initial weight loss, but differences at the end of treatment and at l-year follow-up were not significant (Wing ef al., 1982). These data suggest that prescription of caloric goals, specific diet plans and use of intermittent low-calorie days may not affect the actual degree of caloric restriction and hence may not affect overall weight losses. The weight losses observed during the treatment phase of this study compared favorably with weight losses usually obtained in behavioral treatment programs. On average, clients lost approx. 17 lb during the initial treatment. However. a substantial regain occurred during the year after treatment. There is no clear explanation for this large regain. Weight loss in the present study was strongly related to adherence to several ispects of the program. Those cilents who self-monitored most frequently during the initial IO-week treatment program lost the most weight initially and over the full 15-month study. Long-term weight loss was also related to self-reported caloric expenditure at I year. The importance of exercise in promoting long-term maintenance of weight loss confirms the findings of several experimental studies of exercise (Dahlkoetter, Callahan and Linton, 1979; Harris and Hallbauer, 1973: Stalonas, Johnson and Christ, 1978). General improvement in eating behaviors and use of diaries and frequent weighing were also related to weight loss. Jeffery er nf. (197&, b) noted previously that weight loss during the first week of a weight control program predicted subsequent weight loss during the remainder of the treatment period. In the present study, initial weight Lossdid not predict subsequent weight loss, but weight loss during the pretreatment assessment was related to total weight loss both at the end of treatment and at l-year follow-up. Acknowledgement-Preparation of this study was supported in part by Grant AM 29757-02 from the National Institute of Arthritis, Metabolism and Digestive Diseases.
REFERENCES
Ashby W. A. and Wilson G. T. (1977) Behavior therapy for obesity: booster sessions and long-term maintenance of weight loss. Be&v. Res. ?%er. IS, 453-463. Brownell K. D., Heckerman C. L., Westlake R. J., Hayes S. C. and Monti P. M. (1978) The etTect of couplestraining and partner cooperativeness in the behaviorat treatment of obesity. Behau. Res. Titer. 16, 323-334. Clausen J. D., Silfen M., Coombs J., Ayers S. and Altschul A. M. (1980) Relationship of dietary regimens to success, efficiency and cost of weight loss. J. Am. dier. Ass. 77, 249-257. Craighead L. W., Stunkard A. J. and O’Brien R. M. (1981) Behavior therapy and pharmacotherapy for obesity. Avchs gen. Psychiat. I.%!,763-768. Dahikoetter J., Callahan E. J. and Linton J. (1979) Obesity and the unbalanced energy equation: exercise vs eating habit change. X. consu&. et&r. Psychol. 47* 898-905. Foreyt J. P., Mitchell R. E., Garner D. T., Gee M., Scott L. W. and Gotto A. M. (1982) Behavioral treatment of obesity: resufts and limitations. &&a, Ther. 13, 153-161. Harris M. B. and Hallbauer E. S. (1973) Self-directed weight control through eating and exercise. Behap. Res. Ther. 11, 523-529. Hunt W. A., Barnett H. W. and Branch, L. G. (1971) Relapse rates in addiction programs. J. c/in. Psychoi. 27, 455-456.
CASE HISTORIES
AND
SHORTER
COMMIJNICAT’IONS
449
Jeffery R. W.. Thompson P. D. and Wing R. R. (1978a) Effects on weight reduction of strong monetary contracts for caloric restriction or weight loss. Behav. Res. Thu. 16, 363-369. Jeffery R. W., Wing R. R. and Stunkard A. J. (1978b) Behavioral treatment of obesity: the state of the art 1976. Behac. Ther. 9, 189-199.
Jeffery R. W., Gerber W. M., Rosenthal B. S. and Lindquist R. A. (1983) Monetary contracts in weight control: effectiveness of group and individual contracts of varying size. J. cons&. c/in. Psychol. 51, 242-248. Lindner P. and Blackbum G. (1976) Multidisciplinary approach to obesity utilizing fasting modified by protein-sparing therapy. Obesity bariat. Med. 5, 198-216. Marlatt G. A. and Gordon J. R. (1979) Determinants of relapse: implications for the maintenance of behavior change. In Behavioral Medicine: Changing Health Lifestyles. Brunner/Mazel, New York. O’Neil P. M., Currey H. S., Hirsch A. A., Malcolm R. J., Sexauer J. D., Riddle R. E. and Taylor C. I. (1979) Development and validation of the Eating Behavior Inventory, J. Behav. Assess. 1, 323-132. Stalonas P. M., Johnson W. G. and Christ M. (1978) Behavior modification for obesity: the evaluation of exercise, contingency management, and program adherence. J. consult. c/in. Psychol. 46, 463469. Wilson G. T. and Brownell K. D. (1980) Behavior therapy for obesity: an evaluation of treatment outcome. Adv. Behav. Res. Ther. 3, 49-86.
Wing R. R. and Epstein L. H. (1981) Prescribed level of caloric restriction in behavioral weight loss programs. Addicf. Behav. 6, 139-144.
Wing R. R. and Jeffery R. W. (1979) Outpatient treatment of obesity: a comparison of methodology and clinical results. Ini. J. Obesity 3, 261-279.
Wing R. R., Epstein L. H. and Shapira B. (1982) The effect of increasing initial weight loss with the Scarsdale diet on subsequent weight loss in a behavioral weight control program. J. cons&. clin. Psychol. 50, 446-447.
Intermittent
1984 Copyright
OOOS-7967/84 $3.00 + 0.00 Q 1984 Pergamon Press Ltd
low-calorie regimen and booster sessions in the treatment of obesity
RENA R. WING,* LEONARD H. EPSTEIN, MARSHA D. MARCUS and RANDI KOEXE Weslern Psvchiatric Insiitule and Clinic, University of Pittsburgh School of Medicine, 3811 O’Hara Street, Piusburgh, PA 15213, U.S.A. (Received 21 September
1983)
Summary-The present study investigated two new weight-control strategies: an intermittent low-calorie regimen and intermittent scheduling of booster sessions. A new approach to predicting patient weight loss, based on a pretreatment assessment with a highly-structured eating regimen, was also studied. Forty-eight obese patients were randomly assigned to either a Standard Behavioral weight-control condition or to an Intermittent Low-calorie Regimen ( < 750 cal for 2 days/week) condition and to one of two maintenance schedules: a Spaced schedule in which the six booster sessions were held at monthly intervals, or a Massed schedule, in which four of the six meetings were held during the third month. Neither the intermittent low-calorie regimen nor the intermittent scheduling of booster sessions significantly affected weight loss. However, weight loss at 1 year was related to compliance to self-monitoring and to self-reported change in eating habits and exercise. In addition, weight loss at 1 year was related to weight loss during the initial pretreatment assessment period.
INTRODUCTION Weight losses achieved in behavioral treatment programs are usually modest, averaging 10-20 lb (Foreyt, Mitchell, Gamer, Gee, Scott and Gotto, 1982; Jeffery, Wing and Stunkard, 1978b). These losses are maintained, but not extended during the year after treatment (Wilson and Brownell, 1980: Wing and Jeffery, 1979). Efforts to improve the results of behavioral weight-control programs fall into two basic categories: (a) efforts to increase the rate of weight loss during the initial treatment period; and (b) efforts to increase the length of time during which behavior changes are maintained, and consequently the length of time during which weight loss takes place. Various strategies have been used to increase the rate of initial weight loss. These include the use of anorectic medication (Craighead, Stunkard and O’Brien, 1981), contingency contracting procedures (Jeffery, Thompson and Wing, 1978a; Jeffery, Gerber, Rosenthal and Lindquist, 1983) and more stringent dietary modification (Lindner and Blackburn, 1976; Wing, Epstein and Shapira, 1982). The drugs, contracts or diets are prescribed during the initial weeks of therapy, and discontinued later in the program. Although weight losses are increased while the procedures are in effect, differences in long-term weight losses are usually not observed. The second approach to improving weight loss is to increase the period of time during which behavior changes are maintained. Techniques designed to accomplish this include spouse support (Brownell, Heckerman, Westlake, Hayes and Monti, 1978), relapse-prevention strategies (Marlatt and Gordon, 1979) and booster sessions (Ashby and Wilson, 1977). Booster sessions are typically held at monthly or at gradually increasing intervals to fade the degree of therapist contact. As used, booster sessions have had mixed effects on long-term weight loss (Wilson and Brownell, 1980). In the present study, it was hypothesized that weight losses might be improved by alternating periods of tight behavior control with periods of looser control. This was accomplished through the use of two specific strategies: an intermittent low-calorie regimen and intermittent scheduling of booster sessions. Clausen, Silfen, Coombs, Ayers and Altschul (1980) reported that patients who alternated between a structured, very low-calorie diet ( < 750 cal) for several days a week and a more moderate calorie goal ( 2 1200 cal) on the other days, lost significantly more weight (R = 20.7 lb) than those who remained at the moderate calorie goal throughout (Z? = 10.0 lb). This type of intermittent low-calorie regimen has the advantage that it could be maintained indefinitely, rather than being used initially and subsequently discontinued, However, since patients in the Clausen et al. (1980) study had selected which type of diet to follow, a more controlled test of the intermittent low-calorie regimen was needed. Secondly, a new schedule of booster sessions was investigated. Since previous studies have suggested that patients maintain their behavior changes for the first 3 months after therapy, and then experience relapse {Hunt, Bamett and Branch, 1971), a 3-month period of no booster sessions was followed by a period of frequent booster contacts with weekly meetings for 1 month, and then infrequent contact during the remainder of the l-year follow-up period. It was hypothesized that patients would maintain their weight losses during the 3-month hiatus and then lose additional weight during the month of intense contact, which would be maintained at follow-up. The present study also included a new approach to predicting Ss’ weight loss. Ss were asked to participate in a IO-day pretreatment assessment period, which included several days on a highly-structured, low-calorie eating plan. Weight loss during the pretreatment assessment period was used to predict patients’ weight loss during the subsequent program and overall. METHOD Subjecrs
Newspaper articles and physician referrals were used to recruit patients to participate in the present study. To be eligible, patients had to be aged 20-65, > 20:s overweight, not currently involved in any other weight-control programs and willing *To whom all reprint requests should be addressed. 445
446
CASE
HISTORIES
AND SHORTER
CO.MMUNICATIONS
to participate in a 15-month study. An $85.00 deposit was required: S35.00 was non-refundable; $50.00 was refunded for attendance at treatment and follow-up meetings. Those individuals who were interested in the program were invited to an orientation meeting,at which time the &tail\ of the Program were explained. Ninety-four persons attended the orientation meeting, 17 of these did not meet the entry criteria, and 29 either chose not to enter the study or did not complete the pretreatment assessment period. The remaining 48 Ss (42 females; 6 males) were randomly assigned to a treatment condition. The average weight at entry (mean + SEM) was 203.55 k 5.06 lb (range 139-287 lb). Body mass index (wtiht? averaged 36.45. .S s ranged in age from 20-63. averaging 44.79 f 1.56 years of age. Pretreatment
assessment
All Ss were asked to participate in a IO-day assessment procedure. Ss recorded their intake and physical activity for the 4 days following the orientation meeting. They were instructed to try to maintain their normal pattern of intake and expenditure during this time. For Days 5-7, Ss were given an individually prescribed diet consisting of only Slender breakfast bars (137 Cal/bar) and liquid Slender in cans (225 Cal/can). A calorie goal was calculated for each S (based on present weight x 12 - 1000 cal) and the combination of bars and cans that would most closely achieve this goal was prescribed. For Days 8-10, Ss were instructed to return to regular foods. but to maintam their intake at or below the prescribed calorie goal. Ss were weighed at the orientation meeting, and again on Days 4. 7 and 10 of the screening period. All weigh-ins were held at the same time of the evening. Treatment Subjects who completed the pretreatment assessments were randomly assigned to one of two treatment conditions: Intermittent Low-calorie Regimen or Standard Behavioral condition. Clients in both condittons attended weekly meetings for a lo-week period. Each meeting lasted 60-90 min and consisted of an individual weigh-in, review and collection of food diaries and presentation of a new lesson. Lessons covered energy balance, strategies for increasing exercise, stimulus control. cognitive restructuring, self-reinforcement and relapse prevention. The two treatment conditions differed only in the type of eating plan that was prescribed. Ss in the Standard Behavioral condition were given a calorie goal (based on initial weight x I 2 - 1000 cal). They were told to self-monitor their caloric intake and to stay within the calorie goal. All Ss were given calorie goals of at least lOOOcal/day. Subjects in the Intermittent Low-calorie Regimen were given comparable individualized goals to follow for 5 days/week. For the other 2 days of the week, Ss were advised to practice ‘self-control’ by restricting intake to below 750 Cal/day. Ss were given two specific plans for achieving the low-calorie goal: they could either follow a prescribed low-calorie menu or could return to a combination of liquid Slender and Slender bars. It was explained to Ss that both of these eating plans would simplify the decisions involved with meal selection and would help reduce the stimuli associated with overeating. At the weekly treatment meeting, Ss selected the 2 self-control days for the followmg week, and could thus tailor the self-control days to fit their individual life-style. Booster
sessions
Two schedules of booster sessions were compared (Spaced/Massed). Half of the Ss from each treatment condition were assigned to the Spaced Booster schedule and half to the Massed Booster schedule. To ensure that patients who had been successful during initial treatment were evenly distributed in the two booster schedules, Ss were blocked according to weight loss during the lo-week program (lost < IO lb; lost IO-20 lb; lost > 20 lb) and randomly assigned from within blocks to one of the two booster contact schedules. During follow-up patients were seen m four separate groups, formed from the two treatment conditions (Intermittent Low-calorie/Standard Behavioral) and two booster schedules (Spaced/Massed). Each of the four groups met six times during the 6 months following initial treatment. For the Spaced Booster condition. the six meetings were held at monthly intervals over the 6-month period (Weeks 4. 8. 12. 16. 20 and 24 of the follow-up period). The Massed Booster condition met once at the beginning and once at the end of the 6-month maintenance interval. but their remaining four meetings were massed during the third month of the maintenance interval. The Massed Booster condition met on Weeks 4, 13, 14, 15, 16 and 24 of the follow-up interval. Both conditions were seen again 12 months after initial treatment. The content of the booster sessions was similar for the two conditions. Clients were taught to use problem-solving techniques to identify difficult situations and preplan strategies for coping with these situations. Additional topics related to nutrition and exercise were discussed, such as low-calorie food preparation and exercising in cold weather. Dependent
measures
The nrimarv dependent measure was weight loss, which was measured at each meeting throughout the program. Self-monitori& records were used to assess compliance to the treatment program. To determine whether there were changes in eating habits, Ss completed the Eating Behavior Inventory (EBI; O’Neill, Currey. Hirsch, Malcolm. Sexauer. Riddle and Taylor, 1979) at the start and end of treatment and at 6-month follow-up. A cupboard survey identifying the number of high-, medium- and low-calorie foods currently found in the house was completed before and after the treatment. RESULTS Weight -loss dota Forty-six of the 48 Ss completed the IO-week treatment period. The 2 dropouts (one from each condition) were assumed to have lost no weight. The average weights for all 48 Ss at various points m the IO-week treatment period are presented in Table 1. No significant differences between conditions were observed for weight at the start of the program. Weight loss averaged 3.8 lb during the IO-day pretreatment period and was not slgmficantly different for clients in the two conditions. A repeated-measures analysis of variance was computed to compare the weight loss of the two conditions over the lo-week treatment period. Condition (Intermittent Low-calorie/Standard Behavioral) was used as a between-group factor and time (Weeks I, 5, 10) was used as a repeated measure. Only the effect of time was significant [F(2.92) = 87.35, P < O.OOI]. Clients m the Standard Behavioral condition lost II.71 lb during the IO-week treatment. compared to 14.33 lb for clients in the Intermittent Low-calorie condition. The total weight loss from pretreatment to the end of the IO-week program was 16.24 lb for clients in the Standard Behavioral condition and 17.47 lb for those in the Intermittent Low-calorie condition.
CASE
Table
1. Weight
HISTORIES
AND
SHORTFJR
COMMUNICATIONS
(lb) for Intermittent Low-calorie Regimen and during the IO-week treatment period
change
Standard Behavioral conditions
Treatment Intermittent Lowtaloiie (N = 25) R
Time period Pretreatment weight Weight loss pretreatment Welght loss pretreatment Weight loss pretreatment
to week to week IO
condition
SEM
202.42 + 6.09 - 3.14 * 0.55 - 11.17+0.99 - 17.47 f 1.97
5
week 10
Standard
Behavioral (N = 23) JJ SEM 204.78 - 4.53 - 10.26 - 16.24
i f f +
8.37 0.66 1.50 2.01
The 46 clients who completed the treatment period were blocked according to weight loss and randomly assigned from within blocks to one of the two maintenance strategies. Forty-four of the 46 clients completed the maintenance phase. Table 2 presents the weight changes experienced by these 44 patients during the various phases of treatment. A 2 x 2 analysis of variance, comparing the weight changes of the two treatments (Intermittent Low-calorie/Standard Behavioral) and two maintenance conditions (Spaced/Massed) during the year following treatment (posttreatment to 6 months/6 months to 12 months) was computed. Once again, the only significant effect was for time [F(2,80) = 67.66, P < O.OOl].Clients regained substantial amounts of weight during the year following initial treatment, (8 = 11.70 + 1.88 lb, mean + SEM). There was no significant difference in the amount regained for clients in the Spaced vs Massed Booster sessions. Further, clients in the Massed Booster session lost only an average of 0.45 lb during the month of weekly follow-up meetings. Adherence
To determine whether the lack of difference in weight loss for clients in the Intermittent Low-calorie Regimen and those in the Standard Behavioral condition resulted from the failure to comply with the low-calorie diet, the daily self-report diaries were checked to determine the number of days on which clients reported eating c 750 cai and the number of weeks in which there were 2 or more low-calorie days ( < 750 Cal). Clients in the Intermittent Low-calorie Regimen reported eating < 750 cal on an average of 13.4 + 1.7 days during the IO-week program. This was significantly more than the 5.9 + 1.2 days of low-calorie eating observed in the Standard Behavioral condition [F(1,46) = 12.84, P -z O.OOl].In addition, clients in the Intermittent Low-calorie condition reported eating < 750 cal for 2 days/week during 4.4 + 0.5 weeks of the program, compared to 1.2 f 0.3 weeks for the Standard Behavioral condition [F(1,46) = 28.49, P < O.OOl].These data suggest that the low-calorie days were followed fairly well by clients. However, in spite of compliance to the low-calorie days, the total intake for clients in the Intermittent Low-calorie Regimen (1106.1 + 5O.Ocal) was not significantly different from that of the Standard Behavioral condition (1199.1k 84.0 Cal). To determine whether adhering to low-calorie days resulted in lower overall intake or improved weight loss, the total sample was divided into two groups according to the frequency of self-reported intake below 75Ocal. Those clients who frequently ate less than 750 cal had lower total caloric intake [f(45) = 3.12, P < 0.011 and greater weight losses during treatment [r(46) = 2.23, P < 0.051 than those clients who rarely ate below 750 cal. However, an even stronger predictor of weight loss was the number of weeks in which the client self-recorded intake. Ss were divided into two groups based on the number of weeks in which they had self-recorded their intake for 5 days or more. Those Ss who were more compliant with self-monitoring lost more weight during the IO-week treatment period [ - 18.09 vs - 7.15 lb; r(46) = 5.14, P < O.OOl]. In addition, the total weight loss. from pretreatment to l-year follow-up, was - 10.8 lb for those who were above the median in compliance to self-monitoring. compared to a 3.10 lb weight gain for those who were below the median in compliance to self-monitoring (1(46) = 2.97, P <: 0.011. Behaoior change
Significant improvements in eating habits, as assessed by the EBI, were observed at the end of the IO-week treatment [F(1,40) = 71.86. P < O.OOl]and at the 6-month follow-up [F(1,35) = 27.72, P < O.OOl]. The EBI was not readministered at I year. The 23 clients who completed the cupboard survey also reported significant reductions in the number of high-calorie foods stored in the home [F(1.21) = 9.75, P < 0.011 over the course of the IO-week program.
Table 2. Weight
changes
(lb) for each treatment
and maintenance
intermittent Low-calorie condition Tune period Pre-post R SEM Post-6 months .v SEM 6 Months-12 months R SEM Total (pre-12 K SEM
condition
Standard Behavioral condition
Massed (N = 11)
Spaced (N = 12)
Massed (N = 12)
Spaced (N = 9)
- 19.46 5 3.19
- 17.59 + 2.49
- 16.13 + 2.16
- 18.86 + 3.84
+ 7.41 -+ 4.36
+ 11.58 _t 3.17
+ 8.38 + 2.91
+ 7.45 f 4.03
+4.61 2 1.86
+ 1.56 i 2.32
+ 4.06 * 3.07
+ 0.97 + 4.42
- 7.43 t 5.67
- 4.44 + 4.44
- 3.69 + 2.43
- 10.44 + 5.18
months)
Weight loss from pretreatment to I-year follow-up was correlated with changes on the EBI at the end of treatment (r = 0.41, P < 0.01) and at 6 months (r = 0.61, P < O.OOl),and with reductions in the total number of foods stored in the home (r = 0.50, P c 0.01). In addition, weight loss was significantly correlated with self-reported caloric expenditure at I year (r = 0.50, P < 0.01). Significant correlations were also found between total weight lass and use of the following behavioral strategies: use of eating diaries (r = 0.46, P “E:O.OOl),frequent weighing (r = 0.49. P < 0.001). graphing weight {r = 0.38, P c 0.05) and increasing exercise fr = 0.45, P c O.OOl).
Prior to the program, patients were asked to self-monitor their usuaf caloric intake and exercise for 4 days. Weight loss during this period was minimal (kT *t 0.18 + 0.4 lb). During the subsequent 3 days of pretreatment assessment. when patients were asked to restrict their intake to Slender and to reduce their estimated baseline intake by 1000 cal, there was an average weight loss of 2.8 + 0.3 lb. Patients then returned to regular food but remained at the lower level of caloric intake. An additional 1 lb weigh& loss occurred during this final 3-day period. Overall weight loss, during the 10 days of preassessment. averaged 3.8 I lb and ranged from - t 1.75to + 1.0 lb. Weight loss over the full pretreatment assessment period and during each phase of the assessment was unrelated to subsequenr weight Ibss. However, the weight loss achieved during the preassessment period was correlated with foral weight loss during treatment (I = 0.34, P < 0.05) and over the entire l-year period (r = 0.39, P < 0.01). DlSCUSSION
In the present study, no significant dif&erences in weight loss were observed between clients who were prescribed an inte~ittent low-calorie regimen and those who followed a more moderate calorie regimen throughout. Further, the schedule of booster sessions was not signiticantly related to long-term results. Clients who were seen weekly for a 4-week period during the year of folfow-up lost only 0.5 lb during the month of intense contact and were not significantly different at 6-month or l-year follow-ups from those who were Seen at monthly intervals. The finding that the intermittent low-calorie regimen did not increase weight loss over the standard regimen may be due to the fact that the intermittent low-calorie regimen did not produce a greater reduction in overall caloric intake, as judged from clients’ self-report diaries, than occurred in the more moderate regimen. Two previous studies by Wing et ul. ( 1982; Wing and Epstein, 1981) have likewise failed to show a significant effect of dietary prescription on weight loss. Wing and Epstein (198lf instructed clients to reduce their caloric intake by either small, moderate or large amounts during the initial 5 weeks of a therapy program. This manipulation did not afIect initiai or subsequent weight loss. Aithough clients were prescribed different degrees of caloric restriction, once again their self-reported intake was not significantly different by condition. The use of the Scarsdale Medical Diet at the outset of a behaviorai weight-control program increased initial weight loss, but differences at the end of treatment and at l-year follow-up were not significant (Wing ef al., 1982). These data suggest that prescription of caloric goals, specific diet plans and use of intermittent low-calorie days may not affect the actual degree of caloric restriction and hence may not affect overall weight losses. The weight losses observed during the treatment phase of this study compared favorably with weight losses usually obtained in behavioral treatment programs. On average, clients lost approx. 17 lb during the initial treatment. However. a substantial regain occurred during the year after treatment. There is no clear explanation for this large regain. Weight loss in the present study was strongly related to adherence to several ispects of the program. Those cilents who self-monitored most frequently during the initial IO-week treatment program lost the most weight initially and over the full 15-month study. Long-term weight loss was also related to self-reported caloric expenditure at I year. The importance of exercise in promoting long-term maintenance of weight loss confirms the findings of several experimental studies of exercise (Dahlkoetter, Callahan and Linton, 1979; Harris and Hallbauer, 1973: Stalonas, Johnson and Christ, 1978). General improvement in eating behaviors and use of diaries and frequent weighing were also related to weight loss. Jeffery er nf. (197&, b) noted previously that weight loss during the first week of a weight control program predicted subsequent weight loss during the remainder of the treatment period. In the present study, initial weight Lossdid not predict subsequent weight loss, but weight loss during the pretreatment assessment was related to total weight loss both at the end of treatment and at l-year follow-up. Acknowledgement-Preparation of this study was supported in part by Grant AM 29757-02 from the National Institute of Arthritis, Metabolism and Digestive Diseases.
REFERENCES
Ashby W. A. and Wilson G. T. (1977) Behavior therapy for obesity: booster sessions and long-term maintenance of weight loss. Be&v. Res. ?%er. IS, 453-463. Brownell K. D., Heckerman C. L., Westlake R. J., Hayes S. C. and Monti P. M. (1978) The etTect of couplestraining and partner cooperativeness in the behaviorat treatment of obesity. Behau. Res. Titer. 16, 323-334. Clausen J. D., Silfen M., Coombs J., Ayers S. and Altschul A. M. (1980) Relationship of dietary regimens to success, efficiency and cost of weight loss. J. Am. dier. Ass. 77, 249-257. Craighead L. W., Stunkard A. J. and O’Brien R. M. (1981) Behavior therapy and pharmacotherapy for obesity. Avchs gen. Psychiat. I.%!,763-768. Dahikoetter J., Callahan E. J. and Linton J. (1979) Obesity and the unbalanced energy equation: exercise vs eating habit change. X. consu&. et&r. Psychol. 47* 898-905. Foreyt J. P., Mitchell R. E., Garner D. T., Gee M., Scott L. W. and Gotto A. M. (1982) Behavioral treatment of obesity: resufts and limitations. &&a, Ther. 13, 153-161. Harris M. B. and Hallbauer E. S. (1973) Self-directed weight control through eating and exercise. Behap. Res. Ther. 11, 523-529. Hunt W. A., Barnett H. W. and Branch, L. G. (1971) Relapse rates in addiction programs. J. c/in. Psychoi. 27, 455-456.
CASE HISTORIES
AND
SHORTER
COMMIJNICAT’IONS
449
Jeffery R. W.. Thompson P. D. and Wing R. R. (1978a) Effects on weight reduction of strong monetary contracts for caloric restriction or weight loss. Behav. Res. Thu. 16, 363-369. Jeffery R. W., Wing R. R. and Stunkard A. J. (1978b) Behavioral treatment of obesity: the state of the art 1976. Behac. Ther. 9, 189-199.
Jeffery R. W., Gerber W. M., Rosenthal B. S. and Lindquist R. A. (1983) Monetary contracts in weight control: effectiveness of group and individual contracts of varying size. J. cons&. c/in. Psychol. 51, 242-248. Lindner P. and Blackbum G. (1976) Multidisciplinary approach to obesity utilizing fasting modified by protein-sparing therapy. Obesity bariat. Med. 5, 198-216. Marlatt G. A. and Gordon J. R. (1979) Determinants of relapse: implications for the maintenance of behavior change. In Behavioral Medicine: Changing Health Lifestyles. Brunner/Mazel, New York. O’Neil P. M., Currey H. S., Hirsch A. A., Malcolm R. J., Sexauer J. D., Riddle R. E. and Taylor C. I. (1979) Development and validation of the Eating Behavior Inventory, J. Behav. Assess. 1, 323-132. Stalonas P. M., Johnson W. G. and Christ M. (1978) Behavior modification for obesity: the evaluation of exercise, contingency management, and program adherence. J. consult. c/in. Psychol. 46, 463469. Wilson G. T. and Brownell K. D. (1980) Behavior therapy for obesity: an evaluation of treatment outcome. Adv. Behav. Res. Ther. 3, 49-86.
Wing R. R. and Epstein L. H. (1981) Prescribed level of caloric restriction in behavioral weight loss programs. Addicf. Behav. 6, 139-144.
Wing R. R. and Jeffery R. W. (1979) Outpatient treatment of obesity: a comparison of methodology and clinical results. Ini. J. Obesity 3, 261-279.
Wing R. R., Epstein L. H. and Shapira B. (1982) The effect of increasing initial weight loss with the Scarsdale diet on subsequent weight loss in a behavioral weight control program. J. cons&. clin. Psychol. 50, 446-447.