Overshoot Theory in Eating Disorder Recovery

Written by Lucy Walton

The term ‘overshoot’ is often talked about in recovery and for most people needing to weight restore, can be associated with feelings of anxiety and fear. It is however, an important theory to be aware of and the discussion about expected weight and body shape changes shouldn’t be avoided.


What is overshoot theory?

Our body has a genetically determined weight range and the overshoot theory refers to the point at which the body will gain ‘over’ this weight range. This can happen in recovery from an eating disorder or disordered eating as the body returns to health after a period of starvation and malnutrition. It is normal and not something to be feared.


What is a set point?

Set point is the term used to describe the unique genetic weight range that a person is pre-determined to be at for optimal health and functioning. This set point is different for every body, in the same way we all have different shoe sizes or height which cannot be changed. We can force the body below it, but the body will recognise this and fight to bring it back to where it needs to be. The same applies for if we go above this set point. The human body is amazing and uses many mechanisms to try and defend this weight range, for example changing metabolic rate, hunger signals and altering essential functions such as heart rate and body temperature.


Why does the body overshoot in recovery from starvation?

During a restrictive eating disorder (regardless of body weight), if the body is depleted of energy and essential nutrients for a prolonged period, it becomes starved. Our primal brain doesn’t know the difference between food scarcity or dietary restriction from an eating disorder so any form of nutritional deprivation is seen as a famine. In recovery from a famine, the body will do all it can to protect itself in case another famine occurs. One survival mechanism is to store back up energy as fat, for a certain amount of time until there is no risk of future famine. Once safe, the body will start to use this reserve of energy. Overshoot can be viewed as an essential part of returning to your pre-determined set-point and restoring the optimal ratio of muscle, bone and fat in the body [1].

What did the starvation study teach us about overshoot?

During the Starvation Study in the 1940’s, 36 male participants lost 25% of their body weight to investigate the effect of starvation on the body and brain [2,3]. These participants did not have eating disorders but the psychological and behaviour changes that occurred were similar to those which we now observe in people with eating disorders. One fascinating result of the study was that when the men were able to eat freely again, nearly all of them overshot their pre-starvation weight by an average 10% [2]. Over the course of the following year, their body weight naturally returned (without dieting) to the weight range they were before the experiment, reinforcing the normality of overshoot and it’s role in overcoming starvation.


The danger of stopping halfway

During recovery from an eating disorder it is common to reach a point where people believe they have restored enough weight, despite remaining below a healthy weight for them. This might be reinforced by increased energy levels, getting your period back, improved gut health, increased social engagement and return to many of life's activities. It can be difficult to find a "why" to not stop at halfway. For many, a BMI of 20 is recommended as a minimum weight restoration target (read more about achieving a healthy weight here) with the goal to then learn to eat and move the body intuitively to find a settling weight.


The majority of human beings do not naturally settle at a BMI of 20. So to maintain a this weight when you are not genetically determined to settle there, would mean continuing to engage in disordered eating or other behaviours to control weight. For some people, to achieve weight restoration, overshoot is necessary for an optimal ratio of fat mass to fat-free mass is to be achieved (4). If this process is incomplete, extreme hunger and other symptoms of starvation could continue until fat-free mass is restored. The more severe the starvation the larger the overshoot may need to be (4).


The challenges of overshoot

Talking about this concept in theory is easy said and done, but having a lived experience is understandably scary and anxiety provoking. There will be a constant battle between your eating disorder self and healthy self. The fear of overshooting can hinder full recovery and there are several challenges and beliefs which might need to be overcome:

  • Fat and weight stigma

  • Idolising a thin body (thin ideal)

  • Accepting weight restoration and re-gaining the weight lost as a result of the eating disorder

  • Accepting your healthy body weight and shape


Practical tips to help

Diet culture is constantly sending messages which align with eating disorder thoughts and beliefs about weight, exercise, calories, and the ideal body shape. Overcoming the fear of continued weight gain is one of the biggest challenges in recovery from an eating disorder or disordered eating. Please know that it is possible to learn to trust your body again.

  1. Be kind to yourself - Remember that recovery is hard so showing yourself compassion and kindness is important.

  2. Confide in loved ones - If you’re feeling low or anxious try talking to someone you trust and reaching out for help. You do not have to suffer alone

  3. Reduce and stop body checking - Body checking can reinforce eating disorder behaviours and mindset. Try to notice when you are doing this and why, you could even keep a journal and work to reduce the behaviour

  4. Challenge eating disorder thoughts about your body. The human body is amazing! It does so much to carry us through our lives. Focus on what your body can do for you and what it has already done, that does not relate to weight.

  5. Remind yourself of your "why" in recovery. Try writing down your goals and reasons for choosing to recover from your eating disorder. Refer to these on difficult days or when you need a little more motivation


At TC Nutrition we can help anybody that is struggling with disordered eating or an eating disorder. If you are struggling with weight changes, body image or feeling stuck in recovery please to change your behaviour around calories or would like support to help stop counting calories reach out to the team.


Lucy Walton

TCN Intern


Lucy is a Registered Associate Nutritionist and intern at TCN! With Lucy's background in nutrition and psychology, her aim is to help you become more confident in your food choices and enrich your mindset. You can find Lucy on instagram @lutritionw and her website here


 

REFERENCES:

[1] Dulloo, A., Jacquet, J. and Girardier, L., 1997. Poststarvation hyperphagia and body fat overshooting in humans: a role for feedback signals from lean and fat tissues. The American Journal of Clinical Nutrition, 65(3), pp.717-723.

[2] Keys, A., Brožek, J., Henschel, A., Mickelsen, O., & Taylor, H. L. (1950). The biology of human starvation. (2 Vols.). Univ. of Minnesota Press.

[3] Eatingdisorders.dukehealth.org. 2021. The Starvation Experiment | Duke Center for Eating Disorders. [online] Available at: <https://eatingdisorders.dukehealth.org/education/resources/starvation-experiment> [Accessed 22 November 2021].

[4] Troscianko, E., 2021. Recovering From Anorexia: How and Why Not to Stop Halfway. [online] Psychology Today. Available at: <https://www.psychologytoday.com/us/blog/hunger-artist/201402/recovering-anorexia-how-and-why-not-stop-halfway> [Accessed 22 November 2021].


 

Talia Cecchele Nutrition is a team of registered dietitians specialising in eating disorders and disordered eating. We aim to bring balance back to nutrition, help you to break free from food rules and find food freedom. We offer virtual consultations and group programs so whether you are based in London, the UK or around the world we would love to support you. To enquire about a private consultation please fill out a contact form.