Will I shrink if I don't eat?

November 18, 2025 •

4 min read

Malnutrition affects nearly one in three people globally, encompassing both under- and over-nutrition. While the notion of shrinking from not eating seems like a myth, the science shows that severe, prolonged nutritional deficiency can indeed lead to a reduction in height, particularly through the loss of bone density. This phenomenon is a serious consequence of long-term starvation or eating disorders, not a simple result of dieting.

Quick Summary

Severe, chronic malnutrition can cause a gradual reduction in height in adults due to bone mineral density loss, not a physical shrinking of the stomach. While dieting does not make you shrink, prolonged starvation depletes vital nutrients, leading to serious skeletal health issues like osteoporosis and vertebral compression, particularly in vulnerable groups.

Key Points

Genetic Potential: Adult height is determined by genetics once growth plates close during adolescence; dieting will not make you shrink.
Malnutrition Impacts Bone Density: Severe, chronic malnutrition can cause osteoporosis, a loss of bone mineral density, leading to weak bones susceptible to fractures.
Vertebral Compression Causes Height Loss: The physical 'shrinking' in extreme malnutrition cases is often due to the collapse of weakened vertebrae in the spine, a serious medical condition.
Children are at Risk for Stunting: Malnutrition during childhood and adolescence, a critical growth period, can lead to irreversible stunting and failure to reach genetic height potential.
Health Consequences go Beyond Height: Starvation causes serious health issues, including heart problems, weakened immunity, muscle wasting, and cognitive decline, which are far more critical than height loss.
Appetite Changes, Not Stomach Shrinking: While eating less can reduce your appetite, your stomach itself does not physically shrink in size unless surgically altered.

The idea that you can shrink simply by not eating is a common misconception, often conflated with temporary weight loss from dieting. However, the reality is far more complex and dangerous. A healthy adult’s height is determined by their genetic potential and is primarily achieved during childhood and adolescence before the growth plates in their bones close. The fear of shrinking is not unfounded in cases of severe and long-term malnutrition, but the mechanism is not about literal physical contraction but rather about the degeneration of skeletal health.

The Real Reasons Height Can Decrease

While an adult's skeletal frame is fixed, several factors can cause a loss of height over time. The primary drivers are not related to casual dieting but rather to chronic, severe nutritional deficiencies or disease states. This process is gradual and reflects a profound breakdown of the body's structural integrity.

Bone Mineral Density Loss: The body requires a constant supply of calcium, vitamin D, and other nutrients to maintain bone strength. When food intake is severely restricted, the body pulls calcium from bones to support vital functions, leading to reduced bone mineral density, or osteoporosis. This makes bones brittle and susceptible to fracture.
Vertebral Compression: In cases of severe osteoporosis caused by malnutrition, the vertebrae in the spine can weaken and collapse, a condition known as vertebral compression fractures. The shortening of the spinal column due to multiple compressed vertebrae is one of the most direct ways that a person can "shrink" in height. This is a severe medical condition, not a side effect of skipping a few meals.
Muscle Wasting (Cachexia): Starvation forces the body to break down muscle tissue for energy. The loss of muscle mass, particularly in the core and back, can weaken the support system for the spine, contributing to poor posture and a hunched-over appearance that can make a person appear shorter.

Chronic Malnutrition vs. Short-Term Dieting

It's crucial to distinguish between severe malnutrition and conscious caloric restriction for weight loss. Short-term dieting, even if it involves periods of fasting, does not cause permanent skeletal damage leading to a loss of height. The body is highly resilient and will adapt to moderate caloric deficits without compromising bone structure.

Comparison of Dieting and Malnutrition Effects on Height


Feature	Short-Term Dieting	Chronic Malnutrition/Starvation
Effect on Height	No effect on adult height.	Can cause height loss due to bone density loss and vertebral collapse.
Skeletal Health	No significant impact on bone mineral density.	Severe decrease in bone mineral density leading to osteoporosis.
Appetite	Appetite may decrease as the body adjusts, often leading to smaller food intake requirements.	Changes in hunger hormones like ghrelin, often alongside severe mental and physical health deterioration.
Weight Loss	Primarily involves fat loss, and some muscle if not combined with adequate protein and exercise.	Involves significant loss of fat and critical muscle mass (wasting), potentially including muscle used for breathing and organ function.
Recovery	Reversible, with a return to normal eating and appetite.	Often irreversible skeletal damage, requiring aggressive and monitored nutritional rehabilitation.

The Critical Window for Growth in Children

For children and adolescents, the impact of poor nutrition on height is even more pronounced. The period of active growth, before the closure of growth plates in bones, is a critical window. Chronic undernutrition during this time can result in stunted growth, meaning a child does not reach their full genetic height potential. Factors like eating disorders such as anorexia nervosa that begin in adolescence can have irreversible effects on final adult height. Nutritional deficiencies during infancy and early childhood are major causes of stunting globally.

The Body’s Adaptive Mechanisms

When starved of energy, the body enters a state of high conservation, prioritizing critical functions over non-essential ones like growth or bone maintenance. The hormonal changes that occur are a desperate attempt to stay alive:

Hormonal Shift: During prolonged caloric deprivation, the body decreases the production of hormones that support growth and metabolism, such as insulin-like growth factor 1 (IGF-1). This shifts the metabolic focus from building tissue to preserving energy for immediate survival.
Resource Mobilization: The body cannibalizes its own tissue—first fat, then muscle—to provide the necessary energy and amino acids. This catabolic state is not sustainable and eventually leads to a breakdown of bone and organ systems.

The Bigger Health Picture

Fixating on the fear of shrinking distracts from the far more serious health consequences of severe undereating, such as:

Heart Problems: Severe malnutrition can lead to heart muscle atrophy and dangerous heart rhythm abnormalities.
Weakened Immune System: The immune system is compromised without adequate nutrition, making the body highly vulnerable to infections and diseases.
Mental and Cognitive Decline: Brain function requires a high amount of energy. Nutritional deficiencies can lead to severe cognitive impairment, anxiety, and depression.

If you or someone you know is struggling with a severely restricted eating pattern, it's essential to seek professional medical help. The immediate and long-term health consequences extend far beyond a change in stature.

Conclusion: A Misconception with a Serious Truth

In conclusion, the idea that a person will shrink from dieting is a myth. For a healthy adult, their height is largely determined by genetics and is fixed once growth plates fuse. However, the misconception is rooted in a serious, medical reality. Severe, long-term malnutrition can cause a loss of height in adults due to the weakening of bones (osteoporosis) and the subsequent collapse of vertebrae. This is a symptom of a severe medical crisis, not a simple byproduct of weight loss. For children and adolescents, malnutrition is even more damaging and can lead to permanent growth stunting, preventing them from ever reaching their full genetic height potential. The focus should therefore be on prioritizing health and balanced nutrition, not fearing a mythical shrinkage from dieting.

Frequently Asked Questions

No, normal dieting will not cause you to shrink permanently. Adult height is fixed after your growth plates close. A loss of height only occurs in cases of severe, long-term malnutrition, which leads to skeletal problems like osteoporosis, not from typical dieting.

No, your stomach does not physically shrink from eating less. It is a muscular organ that expands and contracts, and its size remains relatively constant once you reach adulthood. Eating smaller portions can, however, reduce your appetite over time as your body adjusts to new eating habits.

Stunting refers to a failure to reach full genetic height potential, primarily caused by malnutrition during childhood and adolescence when bones are still growing. Shrinking in adults is a pathological process involving a loss of height due to severe bone density loss and vertebral collapse, typically from chronic and extreme undernutrition.

To maintain strong bones, key nutrients include calcium, vitamin D, and protein. Chronic deficiency in these, particularly in older adults, can lead to osteoporosis and bone weakening, which is a cause of height loss in severe cases.

In adults, severe and prolonged malnutrition can cause the body to leach calcium from the bones, leading to osteoporosis. This weakening of the bones can result in vertebral compression fractures, causing the spine to shorten and a person to lose height.

For children experiencing stunting due to malnutrition, catch-up growth is possible with aggressive nutritional rehabilitation, but it is not always complete, especially with long delays in treatment. For adults, the bone damage causing height loss from severe malnutrition and osteoporosis is often irreversible.

Yes, malnutrition in childhood has severe long-term consequences. It is a leading cause of stunted growth, which is often irreversible and can lead to impaired brain development, lower cognitive function, and increased risk of chronic diseases later in life.