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Starvation Syndrome – The Effects of Semi-Starvation

The Starvation Syndrome – Effects of Semi-Starvation handout provides an overview of the Minnesota Starvation Experiment and common symptoms of semi-starvation. It describes how disordered patterns of eating can cause to semi-starvation and the benefits of normalizing food intake through regular eating.

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Introduction & Theoretical Background

Disordered patterns of eating play a central role in the maintenance of anorexia nervosa, bulimia nervosa, binge-eating disorder, and other specified feeding and eating disorders (OSFED). For this reason, psychoeducation regarding the consequences of abnormal patterns of eating are an important aspect of treatment. The transdiagnostic model of eating disorders identifies several processes which contribute to disordered eating across diagnostic groups (Fairburn et al., 2003). These include:

  • Overvalued beliefs about shape, weight, eating, and control. People with eating disorders base much of their self-worth on their ability to control their shape, weight, and eating. Other features of eating disorders are believed to stem from this ‘core psychopathology’, including extreme weight control behaviors (e.g., self-induced vomiting, driven exercise), body-shape checking and avoidance, and preoccupation with weight and appearance (Cooper & Dalle Grave, 2017).
  • Dietary restraint. Overvalued beliefs about shape, weight, and eating lead individuals to establish strict dietary rules which are challenging to maintain. In restrictive eating disorders (e.g., anorexia nervosa), restraint can result in significant weight loss and a severely low body mass index (BMI) due chronic food restriction. In eating disorders where there is a binge-eating component (e.g., bulimia nervosa), difficulties adhering to these strict dietary rules can cause people to abandon attempts to restrain their eating, resulting in episodes of binge-eating.
  • Broader maintaining factors. These can perpetuate disordered eating for some individuals. They include:
    • Mood intolerance.
    • Interpersonal difficulties.
    • Low self-esteem.
    • Perfectionism.

Failure to meet the body’s energy requirements plays an important role in disordered eating (Waller et al., 2007). When the human body is deprived of energy from food, individuals experience a range of problematic symptoms. The Minnesota Starvation Experiment (Keys et al., 1950) provides a vivid account of how food restriction affects people. Most notably, it highlights common symptoms of semi-starvation and the ways in which this ‘starvation syndrome’ can establish and reinforce key features of disordered eating.    

The Effects of Semi-Starvation 

The Minnesota Starvation Experiment is a well-known research study which explored the effects of starvation on behavior between 1944 and 1945. The project took place against the backdrop of World War II: hunger and starvation were commonplace around the globe, but relatively little was known about the effects of starvation or the process of rehabilitation following extended periods of malnutrition.  

Led by the physiologist Ancel Keyes (physiologist), the Minnesota study began in November 1944 and ended in October 1945. The participants were 36 healthy young men who were conscientious objectors to military service. Recruitment into the project was rigorous: participants needed to be in good physical and mental health and demonstrate an ability to work well with others in difficult circumstances.  

The gruelling study was divided into three phases. During the first phase (lasting three months), the participants ate a normal diet while their eating patterns, behavior, and psychology were closely monitored. During the second phase of study (lasting six months), the participants’ food intake was roughly halved, which caused most of them to lose around 25% of their body weight. During the third phase, the men underwent a period of rehabilitation during which they were refed and restored weight. The participants were required to engage in educational activities and exercise throughout the study. 

The changes observed in the participants during the semi-starvation phase of the experiment were variable but nonetheless dramatic. Importantly, some of these changes persisted after the participants had restored weight and resumed normal eating. These side-effects of restricted eating (often referred to as ‘symptoms of semi-starvation’) included the following: 

Biological changes:

  • Increased hunger, cravings
  • Reduced strength, tiredness
  • Gastrointestinal pain
  • Reduced need for sleep
  • Headaches, dizziness
  • Sensitivity to cold
  • Hair loss
  • Edema (swelling)
  • Reduced basal metabolic rate

Psychological changes:

  • Preoccupation with food (e.g., planning meals in detail)
  • Impaired concentration
  • Reduced alertness
  • Impaired judgment and decision-making
  • Rigid and obsessional thinking

Behavioral changes:

  • Changes in the speed of eating (often prolonging meals)
  • Urges to binge and occasional loss of control over food intake
  • Highly ritualized patterns of eating
  • Increased interest in food (e.g., collecting recipes)
  • Desire to hoard
  • Use of hunger-relief behaviors (e.g., chewing gum)
  • Creating unusual ‘concoctions’ of food (e.g., excessive use of spices)
  • Disinterest in other activities 
  • Neglect of personal hygiene

Emotional changes:

  • Depression
  • Anxiety
  • Irritability and angry outbursts
  • Impatience
  • Interpersonal sensitivity
  • Apathy
  • Brief periods of elation

Social changes:

  • Withdrawing from others
  • Isolation
  • Feelings of social inadequacy
  • Strained relationships (e.g., conflicts)
  • Disinterest in sex 
  • Loss of sense of humour

For some participants, the effects of semi-starvation were extreme: two were briefly admitted to a local psychiatric facility and one admitted to eating scraps of food out of garbage cans (Kalm & Semba, 2005). 

The results of the Minnesota Starvation Experiment reveal a great deal about the consequences of food restriction and weight loss. In the context of eating disorders, the results have several important implications. 

  • Symptoms of starvation and symptoms of eating disorders are very similar. This suggests that starvation plays a central role in the experience of eating disorders including anorexia nervosa, bulimia nervosa, binge-eating disorder, and other eating difficulties. 
  • Starvation symptoms are universal and understandable. All the participants in Minnesota study began the experiment in physically and psychologically healthy state, but this changed as a result of food restriction. Many disordered eating behaviors that initially seem unusual, frustrating, or shameful may stem from universal effects of starvation, rather than reflecting anything deeper about the people who carry them out.      
  • Semi-starvation drives eating disorder symptoms. Restricted eating leads to many of the symptoms that individuals with eating disorders struggle with (e.g., preoccupation with food, urges to binge). For this reason, normalizing food intake and reaching a healthy weight play a vital role in recovery from an eating disorder.
  • Semi-starvation maintains eating disorder symptoms. Symptoms of semi-starvation are likely to perpetuate aspects of eating disorders. For example, social isolation may lead to increased preoccupation with weight and eating, while starvation-related emotional distress may fuel disordered eating (e.g., restricting or binge-eating in response to distress).
  • Severe food restriction is not the only cause of semi-starvation. Symptoms of semi-starvation can also arise when people eat irregularly or intermittently, limit their intake of energy-rich foods (most notably, carbohydrates), or engage in compensatory behaviors which reduce energy absorption and storage (e.g., self-induced vomiting or driven exercise).    
  • Starvation effects sometimes persist. Some participants in the Minnesota study continued to struggle with symptoms after their weight and eating had returned to normal. This suggests that learning to regulate food intake and eat intuitively may take some time after food intake has begun to normalize.

Therapist Guidance

Research shows that how we eat and how much we eat can have a big impact on the way we think, feel, and behave. The reason scientists know a lot about this is because of a famous study called the Minnesota Starvation Experiment, which explored the effects of starvation. Can we look at this handout together? I think it could be relevant to the difficulties you are experiencing.
  • Which symptoms of semi-starvation do you relate to? What problems do they cause you?
  • What does the Minnesota study suggest might be causing those symptoms?
  • Semi-starvation can be a result of long periods of restriction, eating irregularly, avoiding foods like carbohydrates, or compensating after eating. How does that fit your pattern of eating?
  • The researchers found that many of the participants’ symptoms of semi-starvation reversed when they ate more regularly and restored weight. How might things improve for you if you tried that?
  • How would you feel about eating more regularly / restoring weight and finding out what happens?

References And Further Reading

  • Kalm, L. M., & Semba, R. D. (2005). They starved so that others be better fed: remembering Ancel Keys and the Minnesota experiment. The Journal of Nutrition, 135, 1347-1352.
  • Keys, A., Brozek, J., Henschel, A., Mickelsen, O., & Taylor, H. L. (1950). The biology of human starvation. University of Minnesota Press.
  • Waller, G., Cordery, H., Corstorphine, E., Hinrichsen, H., Lawson, R., Mountford, V., & Russell, K. (2007). Cognitive behavioral therapy for eating disorders: A comprehensive treatment guide. Cambridge University Press.