Eating disorders and obesity are difficult to understand and challenging to treat. Anorexia nervosa (AN) patients can starve themselves to death. Most people with obesity regain weight lost by dieting within five years; people with bulimia nervosa and binge eating disorder gorge against their wills (1). Typically, researchers and therapists see these problems as the result of psychological issues, poor choices, thin beauty standards, neurobiological dysfunctions or individual differences in self-control. This website challenges these traditional views of eating disorders and obesity and argues that analyzing anorexia nervosa and obesity outside the context of evolutionary history and behavioral ecology generates incorrect attributions. Many eating and weight problems today have their roots adaptions to survive famine. The dysfunctional behaviors are mediated primarily by complex biological mechanisms rather than choice.
Eating disorders and obesity are responsible for considerable disability and death worldwide (2). Anorexia nervosa (AN) in particular has high morbidity and mortality (3) but, despite a confident literature on theory-driven treatments, none has proven better than any other for adults or even better than a control group’s “supportive clinical management” (4, 5). Merciless fat phobia shames the overweight and obese, yet dieting leads to greater weight gain (6). By the time they are middle-aged, American men have joined women in rating unhappiness about their weight as their greatest source of daily stress (7). From concerns about the economic and societal costs of obesity and eating disorders to the individual emotional costs of a losing battle with eating, researchers, physicians, psychologists, philosophers, patients and their families wonder why it is difficult to nourish ourselves properly. Better understanding and treatment of eating disorders and obesity have enormous potential to increase health and happiness.
Eating problems remind us that the conscious mind takes credit automatically for decisions, actions, hungers and emotions arising from nonconscious brain activity (8). Our subjective experience of the choices we make and actions we take is that they are conscious and volitional, while in fact neuroscience research reveals the opposite to be true much of the time. Non-conscious processes generate decisions to which the conscious mind then assigns rationale and experiences itself as making the choice.
Our subjective experience and our preferred way to think about ourselves as conscious rational choice makers bias us to assign conscious choice. People struggling with their eating, clinicians and researchers are thus vulnerable to believing automatically generated explanations of non-conscious choices. Problematic eating is often seen as psychological, even symbolic; people with obesity, binge eating disorder and bulimia are “feeding a hungry heart;” girls and women with AN crave control or want to be as thin as models.
Alternatively, poor choices are attributed to dysfunctional brain circuits and neurotransmitter levels. Some researchers find a dismal synergy between the two types of explanations. For example, in an article titled, “When nothing tastes as good as skinny feels: the neurobiology of eating disorders,” prominent researchers argued that multiple neurobiological dysfunctions allow perfectionistic women to achieve their goals of becoming model thin (9). Such theories rest on a fundamental misconstrual of the concepts of “choice” and “volition” in the realm of energy homeostasis behaviors.
People with anorexia nervosa (AN) restrict food although they are starving; they hallucinate fat on their emaciated bodies and often exercise energetically (10). The baffling symptoms are remarkably homogeneous and highly heritable (11). Moreover, when people attempt to recover, they find their body and mind fight against eating more and exercising less. Their desire to recover is often undone by fears and compulsions that they do not control or understand.
Many species reduce feeding when it would dist