Herman and Polivy’s Restrained Eating Model
HERMAN, C. PETER AND MACK, DEBORAH
(1975). Restrained and unrestrained eating. Journal of Personality, 43, 647-660..
Comments by Michael R. Lowe, Ph.D. (Oct, 2017)
In the 1970s, Stanley Schachter’s “internal-external” theory of obesity was the most influential psychological theory for understanding individual differences in eating behavior and body weight regulation [see SSIB Ingestive Classics#16 on Schachter’s contributions]. However, the idea that individual differences in responsiveness to internal and external cues account for a large amount of the variation in body weight was undermined by two major developments. The first was an influential article by Judith Rodin (1981) describing various problems with the link Schachter made between sensitivity to internal/external cues and weight status. The second was the development of the restrained eating model of eating and weight regulation, which was introduced by C. Peter Herman and Deborah Mack’s classic 1975 paper.
Herman and Mack were influenced by both Schachter’s and Nisbett’s theories of obesity. Nisbett (1972) suggested that obese people might behave differently than those of normal weight because obese individuals, though overweight relative to most of the population, were nonetheless suppressing their body weights below the level they would reach (i.e., their set point for body weight) if they didn’t consciously resist weight gain. Herman and Mack reasoned that in light of society’s increasing emphasis on maintaining a lean body mass, many normal-weight individuals might also restrain their food intake to keep their body weights below their ostensible body weight set points. They measured such restrained eating via an initial version of the Restraint Scale, which was later revised into a 10-item measure (Herman & Polivy, 1984). They hypothesized that if restrained eaters were suppressing their weights by maintaining restraint over their food intake, and if their restraint was undermined by the consumption of a high-calorie food, their underlying hunger would be “released” and overeating would ensue.
Herman and Mack demonstrated exactly this effect in dramatic fashion, using a forced preload paradigm. In this design, groups of restrained and unrestrained eaters participated in an ostensible taste test of ice cream. Participants were randomly assigned to consume either nothing or one or two milkshakes prior to the taste test. Because the restrained eaters were assumed to be inhibiting their everyday food intake, the authors reasoned that the preloads would undermine their chronic restraint, thereby unleashing their underlying hunger. They showed that restrained eaters consumed about 66% more ice cream after consuming one or two milkshakes than they did in the absence of a milkshake, whereas unrestrained eaters consumed about 47% less after the milkshakes. The reduced consumption of preloaded unrestrained eaters was expected, since they were not inhibiting their eating in the first place and simply became satiated after consuming the milkshakes. Restrained eaters, on the other hand, did not simply fail to regulate their eating (like obese individuals did in Schachter’s earlier studies), they actually “counter-regulated” by consuming much more following milkshake preloads than they did after consuming nothing.
These intriguing findings captured the interest of legions of appetite and obesity researchers who were unpersuaded by the then-common psychodynamic theories of food intake and obesity, and who were struggling to understand both the development of the new eating disorder of bulimia nervosa (Russell, 1979) as well as the increasing prevalence of obesity. Peter Herman and Janet Polivy extended the effects associated with restrained eating to several additional phenomena, including salivary response to food cues, distractibility, binge eating, anxiety-induced eating, ego threat and placebo manipulations of hunger. They also expanded the generality of their model by developing the Boundary Model of Eating (Herman and Polivy, 1984). The Boundary Model proposed that restrained eaters’ eating behavior differed in two ways from unrestrained eaters’. First, restrained eaters, by virtue of their history of on-again, off-again dieting, were assumed to experience a shift in the conditions under which feelings of hunger and satiety would develop. Specifically, restrained eaters were viewed as requiring a longer period of food deprivation before they experienced feelings of hunger, and greater food intake before they experienced feelings of satiety, relative to unrestrained eaters. Second, restrained eaters were assumed to impose a “diet boundary” on their eating, which reflected a self-imposed level of restricted caloric intake that would allow them to reach or maintain their desired body weight. This diet boundary could be undermined by a variety of disinhibitory influences, including consumption of a “forbidden food,” experiencing strong negative affect, consuming alcohol and seeing others eat delicious foods.
Limitations in the psychometric characteristics of the Restraint Scale led to the development of two new measures of restrained eating in the 1980s, the Cognitive Restraint Scale from the Three-Factor Eating Questionnaire (TFEQ) (Stunkard & Messick, 1985) and the Restrained Eating scale from the Dutch Eating Behavior Questionnaire (DEBQ; Van Strien, Frijters, Bergers & Defares, 1986). The widespread and enduring effect of the Herman and Polivy’s restrained-eating model on the fields of appetite, eating disorders and obesity is reflected in the number of times the original Herman and Mack study has been cited (2522) as well as the TFEQ (3605) and the DEBQ (2261).
Herman and Polivy’s restraint model also had a major impact on theories of the etiology and maintenance of bulimia nervosa. Polivy and Herman (1985) argued that dieting caused binge eating and suggested that cognitive (rather than physiological) aspects of dieting – such as expectations and beliefs about foods – created this vulnerability. Similarly, the cognitive-behavior therapy (CBT) formulation of the diet-binge link (Wilson & Fairburn, 1993) holds that extreme and rigid dietary rules – not weight loss or physiological deprivation - underlie binge eating in bulimia nervosa.
Finally, like many highly influential theories, Herman and Polivy’s model of restrained eating has generated a good deal of controversy and debate in the field (Lowe, 1993; Lowe & Levine, 2005; Lowe, 2015). These controversies reflect the generative influence of the restraint model, one of the best indicator’s of a theory’s long-term impact. Identifying inconsistencies and gaps in restraint theory is a positive development for the field because it stimulates new ways of thinking about and investigating the phenomena that the restraint model addresses.
Findings that have raised questions about Herman and Polivy’s conceptualization of restrained eating include the following:
- The Restraint Scale is a heterogeneous (multi-factorial) measure that assesses weight fluctuations and overeating as well as cognitive concerns with weight and eating. This multiplicity makes the identification of potential causal influences more challenging.
- Weight suppression (a large discrepancy between past highest and current weight) is a robust predictor of future weight gain in eating disorders and is more consistently related to symptoms of bulimia nervosa than are cognitive measures of dieting or restrained eating. These findings suggest that binge eating has physiological underpinnings.
- The predictions of restraint theory do not extend to the eating behavior of obese individuals.
- The Restraint Scale has consistently been described as a measure of dieting, but individuals who are dieting to lose weight show eating patterns opposite to those of non-dieting restrained eaters.
- Restrained eaters do not consume fewer calories than unrestrained eaters across numerous eating contexts in the natural environment. Thus restrained eaters appear to consume less than they’d like to eat, but not less than they need to eat to maintain their weight (Lowe & Levine, 2005).
- The restrained eating model spawned much of the anti-dieting movement. Dieting is usually ineffective for long-term weight control, but the psychological dangers of dieting appear to be based more on ideology than substance.
In sum, the application of the concept of restrained eating to healthy weight individuals had a paradigm-shifting impact on the fields of appetite, eating disorders and obesity. Since Herman and Mack’s seminal contribution, restraint has largely replaced body weight as the most widely studied source of individual differences in appetite and eating behavior. It is hard for appetite researchers to imagine a time when such research was all about the drive to eat and barely touched on conscious resistance to that drive. Herman and Polivy’s creation of the restrained eating model changed that forever.
1. Heatherton, T. F., Herman, C. P., Polivy, J., King, G. A., & McGree, S. T. (1988). The (mis) measurement of restraint: an analysis of conceptual and psychometric issues. Journal of abnormal psychology, 97(1), 19.
2. Herman, C.P., & Mack, D. (1975). Restrained and unrestrained eating. Journal of Personality, 43, 647-660.
3. Herman, C. P., & Polivy, J. (1984). A boundary model for the regulation of eating. Research Publications Association for Research in Nervous and Mental Disease, 62, 141.
4. Lowe, M.R. (1993). The effects of dieting on eating behavior: A three-factor model. Psychological Bulletin, 114, 100-122.
5. Lowe, M.R., & Levine, A.S. (2005). Eating motives and the controversy over dieting: Eating less than needed versus less than wanted. Obesity Research, 13, 797-805.
6. Lowe, M.R. (2015). Dieting: Proxy or cause of future weight gain? Obesity Reviews, 16 (Suppl. 1), 19–24.
7. Nisbett, R. E. (1972). Hunger, obesity, and the ventromedial hypothalamus. Psychological Review, 79(6), 433.
8. Polivy, J., & Herman, C. P. (1985). Dieting and binging: A causal analysis. American Psychologist, 40(2), 193-201.
9. Rodin, J. (1981). Current status of the internal–external hypothesis for obesity: What went wrong? American Psychologist, 36(4), 361-372.
10. Russell, G. (1979). Bulimia nervosa: an ominous variant of anorexia nervosa. Psychological medicine, 9(3), 429-448.
11. Stunkard, A. J., & Messick, S. (1985). The three-factor eating questionnaire to measure dietary restraint, disinhibition and hunger. Journal of psychosomatic research, 29(1), 71-83.
12. Van Strien, T., Frijters, J. E., Bergers, G., & Defares, P. B. (1986). The Dutch Eating Behavior Questionnaire (DEBQ) for assessment of restrained, emotional, and external eating behavior. International journal of eating disorders, 5(2), 295-315.
13. Wilson, G.T., & Fairburn, C.G. (1993). Cognitive treatments for eating disorders. Journal of Consulting and Clinical Psychology, 61(2), 261-269.