Yes, Your Muscles Can Hurt From Not Eating Enough

October 13, 2025 •

4 min read

According to studies, severely restricting food intake can lead to muscle soreness, general weakness, and reduced physical endurance. This confirms the uncomfortable truth: your muscles can indeed hurt from not eating enough, a symptom of your body operating in survival mode.

Quick Summary

Restricting calories or specific nutrients can lead to muscle aches, cramps, and atrophy. The primary causes involve electrolyte imbalances, protein deficiency, and the body breaking down muscle tissue for energy.

Key Points

Muscle Catabolism: Not eating enough forces your body to break down its own muscle tissue for energy, causing muscle atrophy, weakness, and pain.
Electrolyte Depletion: Inadequate nutrition leads to low levels of minerals like magnesium, potassium, and calcium, resulting in painful muscle cramps and spasms.
Protein Deficiency: Insufficient protein intake prevents proper muscle repair after daily activities or exercise, causing chronic soreness and slow recovery.
Glycogen Depletion: Muscles rely on carbohydrates for fuel. A low-carb or low-calorie diet can deplete glycogen stores, impairing muscle function and leading to cramps.
Micronutrient Shortfall: A deficiency in vitamins like B-complex and D can interfere with nerve signals and mineral absorption, negatively impacting muscle health.
Severe Consequences: In severe cases of malnutrition, the body can break down muscle so rapidly that it can lead to dangerous conditions like rhabdomyolysis.

The Body's Survival Response to Calorie Restriction

When you consistently fail to consume enough calories, your body goes into a defensive, energy-conservation mode. It first uses up its readily available fuel sources, like glucose stored in the liver and muscles as glycogen. Once these reserves are depleted, the body turns to its next available energy sources: stored fat and, critically, muscle tissue. This process, known as catabolism, involves the breakdown of muscle protein to provide amino acids for other vital functions. This muscle wasting, or atrophy, is a direct cause of weakness, pain, and a feeling of general malaise.

The Link Between Depleted Glycogen and Muscle Pain

Carbohydrates are a muscle's primary and most efficient fuel source during exercise. When a low-carb or low-calorie diet leaves your glycogen stores exhausted, your muscles don't have the energy needed to contract and relax properly. This can lead to uncontrolled muscle spasms and cramps, which feel like sharp, intense pain. Athletes, in particular, need to ensure adequate carbohydrate intake to fuel their workouts and prevent post-exercise soreness and fatigue.

The Crucial Role of Electrolytes and Nutrients

Muscle function relies on a delicate balance of electrolytes and key micronutrients. Undereating can easily disrupt this balance, leading to a cascade of painful symptoms.

Electrolyte Imbalances: Minerals like sodium, potassium, calcium, and magnesium are essential electrolytes that conduct the electrical signals responsible for muscle contraction and relaxation. When these minerals are depleted, often due to dehydration or low intake, you can experience painful muscle cramps, twitches, and spasms. Diets that cut out entire food groups can be particularly risky for causing these imbalances.
Protein Deficiency: Protein is the building block for all muscle tissue. If your dietary protein intake is insufficient, the body must break down its own muscle to get the amino acids it needs. This catabolic state not only leads to muscle loss but also impairs the repair process after normal wear and tear, resulting in chronic aches and pain.
Vitamin and Mineral Deficiencies: Beyond electrolytes, other micronutrients play a significant role. A deficiency in vitamin D can interfere with calcium absorption, affecting nerve and muscle function. B vitamins, particularly B6, are crucial for nerve health, and their deficiency can trigger cramps. These deficiencies can cause a range of symptoms, from muscle weakness to severe, widespread pain.

Comparison of Nutritional Effects on Muscle Health


Feature	Adequate Nutrition	Undernutrition
Energy Levels	High and stable, fueled by consistent nutrient intake.	Low and variable, characterized by fatigue and sluggishness.
Muscle Mass	Maintained or increased, especially with adequate protein intake.	Reduced due to muscle breakdown (atrophy).
Muscle Soreness	Occurs typically after strenuous activity and subsides within 48-72 hours.	More frequent, prolonged, and may occur even without exercise.
Cramping	Infrequent and usually tied to dehydration or intense exertion.	More frequent due to electrolyte and glycogen depletion.
Physical Endurance	High, supported by robust energy stores.	Significantly reduced, leading to quicker fatigue.
Recovery	Quick and efficient, as muscles have fuel and building blocks to repair.	Slow and impaired, as the body lacks protein and other nutrients for repair.
Overall Mood	Stable, as the brain has the amino acids for neurotransmitters.	Prone to irritability and mood swings due to nutrient deficiencies.

Risk Factors and Consequences

While occasional muscle soreness from a missed meal is common, chronic or severe pain is a red flag. Individuals on extreme diets, such as very-low-calorie plans or prolonged fasting, are at a higher risk. Eating disorders like anorexia nervosa are also strongly linked to severe muscle pain and weakness caused by chronic malnutrition and multiple nutrient deficiencies. A more serious, though rarer, complication is rhabdomyolysis, a condition involving the rapid breakdown of damaged muscle, which has been reported in cases of severe malnutrition and hypophosphatemia.

Practical Steps to Prevent and Treat Muscle Pain

Preventing muscle pain from undereating begins with a balanced and consistent dietary approach. If you've been experiencing persistent aches, cramps, or weakness, consider the following:

Re-evaluate Caloric Intake: Ensure you are consuming enough total calories to meet your body's energy needs, especially if you are physically active. A registered dietitian can help you determine the right balance for your activity level and goals.
Prioritize Macronutrients: Focus on a balanced intake of carbohydrates, protein, and healthy fats. Carbs provide fuel, while protein is vital for muscle repair.
Replenish Electrolytes: Hydrate properly, especially during and after exercise, and eat foods rich in magnesium, potassium, and calcium, such as leafy greens, nuts, seeds, and bananas.
Get Enough Micronutrients: Include a variety of fruits, vegetables, whole grains, and lean proteins to ensure you are getting a wide spectrum of vitamins and minerals. For deficiencies, a doctor might recommend supplements for short-term support.

Conclusion: Listen to Your Body's Signals

Muscle pain is not always a sign of a good workout; it can be a critical signal from your body that it isn't getting the fuel and nutrients it needs. Ignoring these warning signs can lead to more severe health issues over time, including significant muscle atrophy, fatigue, and systemic health complications. By prioritizing a well-rounded diet, staying hydrated, and listening to your body's feedback, you can protect your muscles and ensure they remain healthy and strong. If your muscle pain persists or is severe, consult a healthcare professional to rule out underlying medical conditions and address any nutritional deficiencies. For more information on nutritional deficiencies, resources like the National Institutes of Health provide valuable insights.

Frequently Asked Questions

When you don't eat enough, your body enters a survival mode where it prioritizes essential functions. It will break down muscle tissue to use as a last resort fuel source, which is a process called catabolism. This breakdown causes muscle atrophy, weakness, and soreness.

Yes. A lack of food and water can cause an electrolyte imbalance, as minerals like sodium, potassium, and magnesium become depleted. These electrolytes are crucial for nerve impulses and muscle contraction, so their low levels can directly cause painful cramps and spasms.

The muscle pain can manifest as frequent and intense cramps or spasms, general aches, and a feeling of weakness or fatigue that doesn't go away. This discomfort can affect muscles even without strenuous physical activity.

Protein is vital for the growth and repair of muscle tissue. Without enough protein from your diet, your body can't repair the micro-tears that occur in muscles from normal use, leading to prolonged soreness and impaired recovery.

Some people on intermittent fasting or very low-calorie diets may experience muscle aches and cramps. This is often due to dehydration and electrolyte imbalance that can occur during the fasting period. Staying hydrated and mindful of nutrient intake is key.

For optimal muscle function, you should focus on adequate intake of protein and carbohydrates. Crucial minerals include magnesium, potassium, and calcium. B vitamins and vitamin D also play important roles in nerve and muscle health.

Normal muscle soreness (DOMS) typically occurs after a strenuous workout and subsides within a few days. Pain from undereating is more chronic and can occur without exercise. It is often accompanied by fatigue and poor energy levels.