When dieting goes too far: The effects of starvation syndrome to look out for in your clients.

February 28, 2023 4 min read

In 1944, in Minnesota, a group of young men took part in a semi-starvation study to understand how food shortages caused by WW2 may impact the European population1. Many physical effects of starvation were expected but the researchers were surprised by the severe cognitive, social, emotional and behavioural effects of semi-starvation. This is the first we knew of starvation syndrome, the survival adaptation to survive prolonged periods of reduced energy intake.

The symptoms described by the participants and researchers back in 1944, parallel what is described by those with starvation caused by eating disorders or prolonged dieting. Still our culture often encourages weight loss dieting and food restriction until the symptoms of starvation become severe.

What is starvation syndrome?

Starvation syndrome is a survival mechanism to conserve energy by shutting down body functioning from the least important for survival to most important. Cognition, self esteem, emotional functioning and relationships are important for our well being, but they are not critical for our short term survival. For those suffering from starvation syndrome, thoughts and life become about food and control as the body seeks to meet its most basic needs.

Who can suffer from starvation syndrome?

Starvation syndrome can occur in those with poor, irregular or unbalanced nutritional intake or if compensatory behaviours reduce energy absorption or increase requirements2. It is commonly seen in those diagnosed with an eating disorder such as anorexia nervosa, bulimia nervosa and binge eating disorder and it can also occur without an eating disorder diagnosis where disordered behaviours around food are present such as calorie restriction or periods of fasting.

All bodies react differently to starvation and this survival mechanism can occur with insufficient energy intake at any body size. Those in larger bodies are at particular risk of having missed eating disorder diagnoses3 or their restricted eating being praised despite the harmful effects to the body.

The effects of starvation on the body

Some symptoms of starvation syndrome can include2:


  • Bloating, constipation and diarrhoea
  • Dizziness and fainting from low blood pressure, reduced heart rate or low blood sugar
  • Hair falling out and skin dryness
  • Reduced heart muscle and weakening of other organs within the body - Poor immune response and slow wound healing
  • Reduced metabolism and extreme weakness and fatigue
  • Feeling cold all the time
  • Decreased hormone levels and shifts in electrolytes and fluids
  • Amenorrhea


  • Irritable mood and increased anger
  • Depression and anxiety
  • Loss of interest in usual activities and life
  • Difficulty coping with emotion or using food (restriction or bingeing) to cope


  • Difficulty concentrating and making decisions
  • Poor memory and impaired comprehension
  • Increased rigid and obsessive thinking
  • Thinking about food all the time
  • Inability to identify hunger and fullness cues


  • Reduced interest or engagement in usual activities
  • Strained relationships
  • Reduced sense of humour and change in personality
  • Low self- esteem and confidence
  • Reduced sex drive and intimacy


  • Cycles of restriction and then binge eating
  • Eating really slow (as to savour the food) or really fast (to get the eating over with) - Obsessive planning of meals or hoarding food
  • Delaying eating until hunger cues are extreme
  • Fear of foods or what the food will do to the body

Can we reverse starvation syndrome?

During recovery from starvation syndrome, an individual has higher energy requirements to reestablish functioning of the body symptoms that are shut down. Once a person is receiving regular, consistent and adequate nutrition, body functions can begin to recover.
These are the general phases taken to support someone to renourish their body and reverse starvation syndrome.

Phase 1: Refeeding

As dietitians we are trained in assessing for refeeding syndrome risk, caused by the body’s shifts in fluid and electrolytes that have adapted to help protect the body during starvation. If the patient may be at risk of refeeding syndrome, it is important to follow clinical guidelines as you begin the renourishing process. The Medical Emergencies in Eating Disorders (MEED)4 guidelines provide guidance for all professionals to safely support those at risk of refeeding syndrome caused by an eating disorder.

Phase 2: Mechanical eating

As starvation syndrome itself affects eating behaviours, attunement with the body’s needs and ability to make decisions, individuals need to be supported with regular eating of meals and snacks, irrespective of hunger, fullness and body attunement. With maintenance of regular and nourishing meals and snacks the body will begin to allocate energy back to the processes it has shut down.

Phase 3: Connection with the body

Only after the body has received adequate and regular nutrition and the individual is weight restored to their usual weight (or a safer weight if natural weight is not known), can connection with the body’s innate signals for hunger and fullness be established and the individual learn to eat intuitively. Disordered thoughts around body image and food fears can make this process more complicated. For those in larger bodies this process is further complicated by societal ideals and weight stigma.

If you suspect a client is experiencing starvation syndrome from dieting or an eating disorder, connecting with a specialist eating disorder dietitian or service is the first step.


Starvation syndrome is a survival mechanism triggered by prolonged energy restriction. Starvation syndrome can affect those with eating disorders or with disordered eating such as prolonged calorie restriction or fasting behaviours. The body shuts down the least important functions for survival to prioritise basic functioning in the body. As a result, starvation syndrome affects an individual’s social, emotional, cognitive and behavioural processes as well as causing physical symptoms.

Author Bio:

Emma Townsin is a UK Registered Dietitian, Certified Intuitive Eating Counsellor and owner of Food Life Freedom. She works with clients helping them to improve their relationship with food and to nourish their bodies without stress or guilt.

You can connect with Emma online

Instagram: @food.life.freedom

Facebook: Food Life Freedom

Website: www.foodlifefreedom.com

Email: emma@foodlifefreedom.com

Profile photo

  1. Eckert, ED et al. Minnesota starvation experiment. A 57-year follow up investigation and review of the Minnesota study on human starvation and its relevance to eating disorders. Archives of psychology. 2018 March; 2(3); 1-19.
  2. Centre for Clinical Interventions. What is starvation syndrome. https://www.cci.health.wa.gov.au Government of Western Australia. 2018 Jan 25. 2. 3.
  3. Harrop, EN et al. Restrictive eating disorders in higher weight persons: A systematic review of atypical anorexia nervosa prevalence and consecutive admission literature. Int J Eat Disord. 2021 Aug; 54(8) [Cited 2023 Feb 17]. 1328-1357. DOI: 10.1002/eat.23519
  4. Royal College of Psychiatrists. Medical Emergencies in Eating Disorders: Guidance on Recognition and Management. https://www.rcpsych.ac.uk/ 2022 May. 185.