Low Calorie Diet Reasons for Sudden Constipation

Although eating fewer calories than you burn is a key component of weight loss, low calorie diets can sometimes have adverse effects. Along with hunger and cravings, some types of low-calorie diets can result in constipation, which occurs when you have fewer than three bowel movements per week. Modifying your low-calorie diet may help prevent or relieve this condition.

A fibrous fruit, kiwi. (Image: iSailorr/iStock/Getty Images)

Low Fiber Intake

Fiber is essential for maintaining healthy bowel function, but some low calorie diets may cause a reduction in overall fiber intake or limit your intake of high-fiber foods. Low-carbohydrate diets, in particular, may lower your fiber intake and subsequently result in constipation. A study published in the February 1990 issue of the "International Journal of Obesity" found that adding fiber to a very low calorie diet helped increase the frequency of bowel movements. Taking a fiber supplement or consuming high-fiber foods like vegetables may help relieve constipation on a low calorie diet.

Dehydration

A common cause of constipation is dehydration, according to the National Digestive Diseases Clearinghouse. Because water and other liquids add bulk to your stools and fluid to your intestinal tract, dehydration can make it more difficult to have bowel movements. In addition, if your low calorie diet includes diuretics or caffeine to curb hunger, you may increase your risk of dehydration due to excreting more fluids from your body. MayoClinic.com recommends drinking 8 to 9 cups of water daily for optimal hydration.

Physical Inactivity

When you drastically reduce your calorie intake, you may feel fatigue or a lack of motivation to exercise. Although the exact mechanism is unclear, lack of physical activity can contribute to constipation. Making an effort to engage in exercise, or slightly increasing your calorie intake so you have enough energy to work out, may help relieve constipation on a low calorie diet.

Ketosis

Low calorie diets that induce ketosis, a condition where your body produces ketones for energy, may result in constipation. Diets that are very high in fat and low in carbohydrates and protein are most likely to result in ketosis and lead to bowel problems. Increasing your carbohydrate intake may help prevent constipation related to ketosis.