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  • Writer's pictureCatherine Lott

The Adapted to Flee Hypothesis and Eating Disorders

Eating disorders, particularly anorexia nervosa (AN), present a complex interplay of psychological, biological, and social factors. One intriguing perspective that has gained attention is the "Adapted to Flee Hypothesis" (AFH), which you've probably heard of on social media somewhere, proposed by Dr. Shan Guisinger in 2003.

This hypothesis suggests that certain traits associated with AN may have evolved as adaptive mechanisms to aid survival during times of famine. This article delves into the AFH, examining its origins, supporting evidence, and its implications for understanding and treating eating disorders.

Origins of the Adapted to Flee Hypothesis

The Adapted to Flee Hypothesis posits that the symptoms of AN, such as hyperactivity, denial of starvation, and an obsessive focus on food, may have evolved as survival mechanisms during periods of food scarcity. According to Guisinger, these traits would have been advantageous for early humans, who needed to migrate to find new food sources. The hypothesis draws on evolutionary psychology to explain why these behaviours might persist in modern contexts where they are maladaptive.

Key Components of the Hypothesis

  1. Hyperactivity and Restlessness: During famine, increased activity levels would have helped individuals travel long distances in search of food. In individuals with AN, hyperactivity and an aversion to rest are common symptoms, potentially reflecting this ancient survival strategy.

  2. Denial of Starvation: A reduced perception of hunger and denial of the severity of one’s condition would have been beneficial for maintaining the motivation to continue moving despite lack of food. In modern contexts, this manifests as a distorted body image and lack of recognition of the seriousness of one’s condition in individuals with AN.

  3. Obsession with Food: Preoccupation with food and eating rituals might have helped individuals remember and utilize scarce food resources effectively. This is mirrored in the obsessive thoughts and behaviours around food seen in those with AN.

Supporting Evidence

Several lines of evidence lend credibility to the Adapted to Flee Hypothesis:

  • Anthropological Evidence: Studies of historical and contemporary hunter-gatherer societies show that periods of food scarcity often require significant physical exertion and migration to new areas .

  • Biological Mechanisms: Research indicates that individuals with AN often exhibit elevated levels of physical activity and reduced feelings of hunger, potentially linked to altered neurobiological pathways involving serotonin and dopamine .

  • Genetic Factors: Twin studies have shown a heritable component to AN, suggesting that genetic factors might underlie these adaptive traits. Genetic predispositions to high activity levels and lower hunger sensitivity may have been selected for in our ancestors .

Criticisms and Limitations

While the AFH offers a compelling evolutionary perspective, it is not without its critics:

  • Lack of Direct Evidence: Much of the supporting evidence is circumstantial and based on correlational data. Direct evidence linking these traits specifically to an evolutionary advantage during famine is sparse.

  • Modern Environmental Triggers: Critics argue that the AFH may underplay the role of modern sociocultural and environmental factors in the development of AN. The pressures and influences of contemporary society, such as media portrayals of thinness, are significant contributors to eating disorders.

  • Individual Variability: Not all individuals with AN exhibit hyperactivity or denial of hunger, suggesting that the hypothesis may not account for all cases.

Implications for Treatment

Understanding AN through the lens of the AFH can have important implications for treatment:

  • Targeting Hyperactivity: Interventions might focus on managing hyperactivity and encouraging rest, which could help reduce the physiological stress associated with excessive activity.

  • Cognitive Behavioural Approaches: Therapies that address distorted body image and denial of illness could be tailored to acknowledge these as evolutionarily rooted behaviours, helping patients reframe their understanding of their symptoms.

  • Nutritional Rehabilitation: Recognizing the deep-seated nature of food obsession could inform more effective strategies for nutritional rehabilitation, ensuring a more compassionate and understanding approach to recovery.

The Adapted to Flee Hypothesis provides a fascinating evolutionary framework for understanding the behaviours associated with anorexia nervosa. While not without its challenges, it offers a unique perspective that highlights the potential origins of these maladaptive traits. Further research is needed to fully validate this hypothesis and integrate its insights into comprehensive treatment approaches. By considering both evolutionary and modern influences, we can develop a more nuanced understanding of eating disorders and better support those on the path to recovery.


  1. Guisinger, S. (2003). Adapted to flee famine: adding an evolutionary perspective on anorexia nervosa. Psychological Review, 110(4), 745-761.

  2. Kaye, W. H., Fudge, J. L., & Paulus, M. (2009). New insights into symptoms and neurocircuit function of anorexia nervosa. Nature Reviews Neuroscience, 10(8), 573-584.

  3. Holtkamp, K., Müller, B., Heussen, N., Remschmidt, H., & Herpertz-Dahlmann, B. (2003). Depression, anxiety, and obsessionality in long-term recovered patients with adolescent-onset anorexia nervosa. European Child & Adolescent Psychiatry, 12(4), 191-196.

  4. Bulik, C. M., Slof-Op 't Landt, M. C., van Furth, E. F., & Sullivan, P. F. (2007). The genetics of anorexia nervosa. Annual Review of Nutrition, 27, 263-275.

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