Low-carbohydrate diets can lead to weight loss, but they are not without risk. If you cut your carb intake too low or you eliminate certain food choices completely, you may find yourself struggling with muscle aches, pains or cramps. Tweaking your diet to address the reasons behind aching and cramping can help. However, if your muscle aches become concerning or do not subside over time, contact your doctor.
If you are very active, your muscle aches may be occurring due to a lack of carbs. Your body stores carbs in the muscles in the form of glycogen, which is used during exercise for energy production along with stored fat. The proportion of fat and carbs used for fuel during exercise varies depending on the intensity. Higher-intensity exercises, like interval training, rely more heavily on stored glycogen. If you are not eating enough carbs to give your muscles the energy they need, you will likely struggle through your workout routine and end up with sore, achy muscles in the following days. The only two fixes for this problem are to increase the amount of carbs you eat each day or to reduce the intensity of your workouts.
The initial weight loss in low-carb diets is mostly water weight, as carbs are stored in the muscles with molecules of water. A significant reduction in carb intake and concurrent weight loss may result in mild dehydration. Some researchers believe dehydration may play a role in muscle aches and cramps. To address this issue, stay well hydrated every day. The Institute of Medicine recommends men drink approximately 3 liters and women approximately 2.2 liters of fluid per day for optimal hydration.
Lack of Potassium
If your muscle ache occurs as a cramping sensation, then the problem could be a lack of potassium. Potassium is a mineral involved in electrolyte balance and muscular contractions, and some researchers believe it plays a role in muscle cramping. It is found in many fruits and vegetables that are sometimes limited on a low-carb diet, including bananas, cantaloupes, potatoes, sweet potatoes and beans. The Institute of Medicine recommends adults consume at least 4,700 milligrams of potassium each day. To meet these needs, consider adding back some of the foods mentioned, or focus on including a variety of low-carb sources of potassium including beet greens, spinach, avocado, mushrooms, tomatoes, fish and meat.
Lack of Magnesium
Magnesium is another electrolyte involved in muscular contractions. Limited evidence suggests that lack of magnesium in the diet may lead to muscle aches and cramps. In addition, magnesium is sometimes used as a treatment protocol for cramping, especially among pregnant women. Since low-carb diets may fall short in magnesium by reducing or eliminating two of the most common sources -- whole grains and beans -- it could be a potential reason for muscle aches or cramps on this type of diet. To ensure you are meeting your needs each day, add in extra servings of lower-carb magnesium-rich foods like leafy green vegetables, almonds and pumpkin seeds.
- The American Journal of Clinical Nutrition: Substrate Utilization During Exercise in Active People
- Human Kinetics: Learn the Connection Between Diet and Muscle Cramping
- Medline Plus: Muscle Cramps
- The Beverage Institute for Health and Wellness: Hydration Guidelines
- Institute of Medicine: Dietary Reference Intakes: Water, Potassium, Sodium, Chloride, and Sulfate
- Canadian Family Physician: Muscle Cramps and Magnesium Deficiency: Case Reports
- The Cochrane Database of Systematic Reviews: Magnesium for Skeletal Muscle Cramps
- Linus Pauling Institute: Potassium
- Linus Pauling Institute: Magnesium