Starvation mode is a physiological response that occurs when the body is deprived of adequate nutrition over an extended period of time. This can occur when food and calories are reduced for an extended period of time. It is not limited to people of a certain size or weight, and can occur for a variety of reasons.
The effects are the same, regardless of why the restriction occurs. For example, it can occur due to eating disorders, or an external cause, like the experiment below. In this state, the body’s metabolism slows down and its energy requirements decrease in order to conserve energy and preserve vital organs. This response is an adaptive mechanism that the body uses to cope with a lack of food.
What is Starvation Syndrome?
Starvation mode is commonly associated with an eating disorder, such as anorexia nervosa and bulimia nervosa. These involve restriction of food intake or episodes of bingeing and purging. When the body is restricted of nutrition in this way the bodies may enter a state of starvation mode. In an attempt to conserve energy and protect against further weight loss.
You may have heard that your body will go into “starvation mode” if you try to lose weight too quickly, making it harder to lose weight in the long run. Restricting your calories can, counterintuitively, make your body hold on to fat stores. One reason for this is because your body simply doesn’t know the difference between intentional weight loss and actual food scarcity, and so it will try to protect you from a perceived famine. Ultimately the body does not want to be sick or to die, so it will do its best to preserve itself.
Effects of Semi-Starvation:
Starvation mode is not all about feeling hungry, whilst this is a part of it, there are more side effects. In addition to physiological changes, starvation mode can also have psychological effects. These can include increased anxiety, irritability, and depression. You may have noticed these in yourself, think about times you have skipped a meal and reached “hangry” status. In semi-starvation this is a lot worse. Then of course these effects may contribute to the development and maintenance of eating disorders.
- Physical effects: When the body is in a state of semi-starvation, it slows down its metabolism in order to conserve energy. As a result, weight loss occurs, and the body may start to break down muscle tissue for energy. The immune system also weakens, making individuals more susceptible to infections and illnesses. Nutrient deficiencies can also occur, leading to a range of health problems, such as anaemia, vitamin deficiencies, and osteoporosis.
- Mental effects: Semi-starvation can also have significant psychological effects. Individuals may experience increased anxiety, irritability, and depression, as well as difficulties with concentration and memory. There may also be a preoccupation with food, as well as feelings of guilt and shame surrounding eating.
- Social effects: Semi-starvation can impact an individual’s social life, as it may interfere with their ability to engage in social activities or maintain relationships. Additionally, it may lead to isolation, as individuals may feel ashamed or embarrassed about their eating habits or physical appearance.
- Eating disorder development: Semi-starvation can also contribute to the development of eating disorders, such as anorexia nervosa and bulimia nervosa. Individuals who engage in semi-starvation may develop an unhealthy relationship with food and body image, leading to disordered eating patterns.
The Effects of Semi-starvation: The Minnesota Starvation Experiment.
Much of our understanding of semi-starvation comes from the Minnesota Starvation Experiment. This was a trial from the 1940’s that can’t be repeated today due to it’s unethical long-term restriction of nutrition. A group of young, healthy men had their calorie intake reduced by half for 6-months to measure the impact on their health. The impacts of this restriction included:
- Heart muscle reducing in size
- Reduced blood pressure and heart rate
- Feeling cold
- Dry skin
- Hyperfixation on food -such as planning, thinking about food, hoarding recipes, eating very quickly (or slowly)
- Impaired focus, concentration and decision-making skills
- Reduced alertness
- Depression, anxiety, irritability and a lack of interest in life
- Social withdrawal and strained relationships
So what does a decades-old study have to do with you? The Minnesota Starvation diet demonstrates what can happen after a few weeks or months of calorie-restriction. In fact, the amount of calories eaten by the participants of the study was of a similar amount to some popular diets.
Is starvation mode real?
Semi starvation isn’t just something that occurs only in the most extreme of restricted diets or for eating disorder in-patients. It can occur through prolonged dieting and restriction. It also isn’t limited to a certain body weight. Even if your body weight is above the “underweight” BMI category, you may still be affected by semi-starvation. Starvation syndrome occurs in response to the intensity of and time spent in caloric restriction, not the number on the scales.
According to the Centre for Clinical Interventions, “Starvation syndrome may be observed if a person’s nutritional intake is poor, irregular, or unbalanced, or if they engage in compensatory behaviours that reduce energy absorption, irrespective of their weight. Individuals with anorexia nervosa, bulimia nervosa and binge eating disorder are therefore all vulnerable to experiencing symptoms of semi-starvation.” This shows how eating irregularity, cutting out food groups or engaging in compensatory behaviours can also lead to semi-starvation, as well as restriction.
How to recover from semi-starvation?
The only way to recover from semi-starvation is to increase calories and/or nutritional intake, and to restore weight to a healthier level where needed. This will likely involve eating a balanced diet that includes all food groups (excluding those removed for allergies/intolerances or cultural reasons), eating at regular intervals and reducing compensatory behaviours. If you have an eating disorder, this may feel scary.
Because of this, a structured “renourishment” period is recommended. Here, food intake is gradually increased to meet the body’s needs in a safe, supported manner. Because long periods of restriction can impact your feelings of hunger/fullness or control around food, there can be an adjustment period. Having a renourishment plan gives time to return to more “normal” levels of control and hunger cues.
Recovery can take time, and symptoms of semi-starvation may persist for a while after food and calories have increased. Know that this is normal, and expected, and not a sign that you can’t recover. Consistency is key, as irregular eating can be a driver of semi-starvation. Focus on following a structured approach to recovery and eating to best support your recovery and relationship with food.
It is important to note that while starvation mode is a natural response to a lack of food, the impacts of this on your body can be complex and long lasting -there is a much bigger picture going on than just how easily you may lose weight. Prolonged starvation can lead to nutrient deficiencies, organ damage, and even death. Therefore, it is important for individuals with eating disorders to seek treatment to restore their physical and mental health.