Not Size Matters, But Diet Complexity
Many people think the success of dieting, seemingly a national obsession following the excesses and resolutions of the holiday season, depends mostly on how hard one tries — on willpower and dedication. While this does matter, new research has found that a much more subtle aspect of the diets themselves can also have a big influence on the pounds shed — namely, the perceived complexity of a diet plan’s rules and requirements.
Cognitive scientists from Indiana University and the Max Planck Institute for Human Development in Berlin compared the dieting behavior of women following two radically different diet plans and found that the more complicated people thought their diet plan was, the sooner they were likely to drop it.
“For people on a more complex diet that involves keeping track of quantities and items eaten, their subjective impression of the difficulty of the diet can lead them to give up on it,” reported Peter Todd, professor in IU’s Department of Psychological and Brain Sciences.
Jutta Mata, now a professor of psychology at Stanford University, said this effect holds even after controlling for the influence of important social-cognitive factors including self-efficacy, the belief that one is capable of achieving a goal like sticking to a diet regimen to control one’s weight.
“Even if you believe you can succeed, thinking that the diet is cognitively complex can undermine your efforts,” she said.
Dieting is not all in one’s head — environment matters, too, the professors say. The physical environment has to be set up properly, such as putting snack foods out of sight to avoid mindless eating. But the cognitive environment, they say, must also be appropriately constructed, by choosing diet rules that that one finds easy to remember and follow.
For people interested in following a diet plan, Mata suggests they take a look at several diet plans with an eye toward how many rules the plans have and how many things need to be how many things need to be kept in mind.
“If they decide to go with a more complex diet, which could be more attractive for instance if it allows more flexibility, they should evaluate how difficult they find doing the calculations and monitoring their consumption,” she said. “If they find it very difficult, the likelihood that they will prematurely give up the diet is higher and they should try to find a different plan.”
About the study: The study examined both the objective and subjective complexity of two diet plans. Brigitte, the cognitively simpler of the two, is a popular German recipe diet that provides shopping lists for the dieters, thus requiring participants to simply follow the provided meal plan. Weight Watchers assigns point values to every food and instructs participants to eat only a certain number of points per day. The 390 women involved were recruited from German-language Internet chat rooms dealing with weight management and were already in the midst of using one of the two diet plans. They answered questionnaires at the beginning, mid-point and end of an eight-week period.
While losing weight initially isn’t rocket science, keeping it off remains a challenge to dieters. It generally is believed that the longer people can adhere to their diet plan, the more successful they will be long-term with their weight loss maintenance. And the more like rocket science one’s diet plan feels, Todd and Mata report, the less likely that long-term adherence and maintenance is to succeed.
Appetite, 2009; DOI: 10.1016/j.appet.2009.09.004- Article in Press, Corrected Proof
When weight management lasts: Lower perceived rule complexity increases adherence.
Jutta Mata a, b, Corresponding Author
Peter M. Todda, c,
Sonia Lippke d
a Center for Adaptive Behavior and Cognition, Max Planck Institute for Human Development, Lentzeallee 94, 14195 Berlin, Germany
b International Max Planck Research School “The Life Course: Evolutionary and Ontogenetic Dynamics (LIFE)”, Berlin, Germany
c Cognitive Science Program, Indiana University, Bloomington, 1101 E. 10th Street, Bloomington, IN 47405, USA
d Department of Health Psychology, Freie Universität Berlin, Habelschwerdter Allee 45, 14195 Berlin, Germany
Received 27 December 2008;
revised 4 September 2009;
accepted 8 September 2009.
Available online 12 September 2009.
Abstract Maintaining behavior change is one of the major challenges in weight management and long-term weight loss. We investigated the impact of the cognitive complexity of eating rules on adherence to weight management programs. We studied whether popular weight management programs can fail if participants find the rules too complicated from a cognitive perspective, meaning that individuals are not able to recall or process all required information for deciding what to eat. The impact on program adherence of participants’ perceptions of eating rule complexity and other behavioral factors known to influence adherence (including previous weight management, self-efficacy, and planning) was assessed via a longitudinal online questionnaire given to 390 participants on two different popular weight management regimens. As we show, the regimens, Weight Watchers and a popular German recipe diet (Brigitte), strongly differ in objective rule complexity and thus their cognitive demands on the dieter. Perceived rule complexity was the strongest factor associated with increased risk of quitting the cognitively demanding weight management program (Weight Watchers); it was not related to adherence length for the low cognitive demand program (Brigitte). Higher self-efficacy generally helped in maintaining a program. The results emphasize the importance of considering rule complexity to promote long-term weight management.
Keywords: Cognitive complexity; Weight management; Weight loss program adherence; Cox hazard regressions; Self-efficacy