Thus far we have highlighted three neurobehavioral processes that promote overeating and obesity: 1) neurobiologically-based behavioral sensitivity to the rewarding properties of food, mediated by the mesolimbic dopamine system, 2) relative weakness in inhibitory control, mediated by the PFC (particularly dorsolateral regions), and 3) steeper discounting of the delayed rewards of weight loss relative to the immediate pleasure associated with eating, reflecting the interaction between the mesolimbic system and the PFC. There are at least three implications of this neurobehavioral model for dietary counseling for obesity.
First, the model explains eating behaviors which promote obesity without invoking character flaws (e.g., lack of willpower). By emphasizing genetically-influenced neurobiological processes that confer vulnerability to overeating in a toxic food environment, the model enables dietitians to more effectively address obesity (as discussed below) without promoting stigma.
Second, the neurobehavioral model preserves a sense of individual control. Though it may seem counter-intuitive, shifting the focus away from “personal choice” and towards the environmental and neurobehavioral processes involved in eating can encourage patients to take an active stance in their approach to weight management. We recommend that dietitians simultaneously convey two messages about weight control to their patients: 1) obesity is heavily influenced by genetic and environmental factors, and an epidemic of obesity is precisely what would be expected given the genetic heritage of our species and the omnipresence of palatable food in the environment; and 2) successful weight management can be achieved by taking active steps (such as those described below) to minimize the impact of the environment on eating behavior. The first message acknowledges that patients are working against potent genetic vulnerabilities and a toxic food environment, and normalizes patients’ (and dietitians’) frustration with failed attempts at weight control. The second message signals that patients can better control their weight through strategies focused on the interaction between the brain and the environment. For the majority of dietitians, this second message constitutes a shift in strategy from urging patients to make the “tough choices” required for weight control to helping patients minimize the number of tough choices they encounter. This differs from the traditional approach to obesity counseling, which by simply encouraging patients to eat fewer calories than they expend, ignores the very processes that make this advice so difficult to follow.
Finally, the framework presented above supports an increased emphasis on several behavioral strategies that have been considered adjuncts to dietary counseling for many years (90
) (). Dietitians should assist patients in manipulating their environments to minimize exposure to palatable food cues, a step that is essential to reducing energy intake by preventing activation of the brain’s reward circuitry that generates the motivation to eat. For example, patients should remove tempting, high-calorie foods from their home and workplace. Of course, the decision to bring high-calorie foods into the home is made at the food store, and shopping from a grocery list or using online grocers (e.g., Peapod) can help reduce one’s susceptibility to the torrent of food cues at the supermarket (91
). Another strategy involves learning to minimize exposure to stress and developing more effective stress reduction strategies, as stress promotes overeating and obesity by enhancing food reward processing (92
) and disrupting inhibitory control (94
). Dietitians may briefly review stress management techniques, encourage exercise as a stress reduction strategy, and refer patients to appropriate behavioral specialists. Finally, consideration of time discounting would suggest that increasing the delay to food rewards and decreasing the delay to weight loss rewards promotes better adherence to dietary goals. Consistent with this idea, patients should be encouraged to prepare healthy foods in advance to make them immediately accessible, keep tempting snacks out of the home (thus requiring a trip to the food store to obtain them), and focus on achieving short-term behavioral weight control goals (e.g., meeting a daily calorie goal) rather than focusing exclusively on long-term weight loss. The focus on short-term behavioral goals may be especially important considering that the rate of initial short-term weight loss is predictive of long-term weight loss outcomes (96
), and that unrealistic long-term weight loss expectations are sometimes associated with poorer outcomes and higher attrition from weight loss treatment (97
; also see 98
). Focusing on achieving short-term behavioral goals would likely have the dual benefits of promoting early weight loss through behavior change and de-emphasizing any unrealistic weight loss expectations patients may have.
Summary of a neurobehavioral model of personal choice in obesity
As the neurobehavioral basis of eating behavior advances, so will our understanding of obesity and weight control. However, enough progress has been made to enable dietitians to shift from a model of obesity counseling grounded in personal choice to one rooted in the brain processes that govern eating behavior in an obesity-promoting environment. In addition to providing nutrition education and encouragement, dietitians should more heavily focus on helping patients overcome the brain-based processes that make dietary modification so difficult, largely through strategies that have been considered “behavioral adjuncts” to dietary obesity counseling for many years. Dietary lapses or failures should be conceptualized as the result of brain systems interacting with a toxic food environment, and not as a reflection of poor personal choices or lack of willpower. Even if this approach is no more effective in producing weight loss than current practices, it is much less likely to elicit patient stigmatization.