We don't really know enough about all the factors that cause specific food cravings. More research is needed to help understand appetite. Many studies suggest that a decrease in blood sugar stimulates hunger. This might help explain a craving for foods high in carbohydrates, which are a quick energy source.
Other studies suggest that the "mind-mood-food connection" may be explained by decreases in the brain chemical serotonin (sair-oh-TO'nin). Serotonin helps you feel less pain, anxiety and stress, so it improves mood by increasing relaxation. Some experts think that people who crave carbohydrates have low serotonin levels. Others caution that these cravings may just be a learned response.
What is "carbohydrate craving" or "carbohydrate addiction?"
These terms are used in a theory about the relationship between carbohydrate, insulin and appetite. (The body uses the hormone insulin to convert sugar, starch and other foods into energy.) We know that eating carbohydrates raises insulin, which then lowers blood sugar. This causes a desire (or craving) for more food and, in some people, carbohydrates.
Some people advocate severely reducing carbohydrate intake to reduce the insulin response and cravings. Others suggest that choosing carbohydrate-containing foods with a lower glycemic (gli-SE'mik) index also can lower insulin response and appetite. There isn’t enough research in this area for us to know what’s right. Also, individual responses may vary considerably.
What are the potential problems of severely reducing carbohydrate intake?
Diets low in carbohydrate are likely to lack sufficient amounts of essential nutrients found in plant foods that promote good health. People following these diets may not get enough vitamins, minerals and fiber to avoid blood chemistry imbalances, constipation and other health problems.
What's missing if carbohydrate-containing foods are severely restricted?
The American Heart Association recommends choosing a wide variety of foods low in saturated fat, trans fat and cholesterol. While people need to watch their calorie intake to prevent overweight and obesity, they should consume a diet rich in vegetables, fruits, and whole grains/high-fiber foods daily. Combined with two to three servings of fat-free or low-fat dairy products, most healthy diets will contain at least 45–65 percent of calories from carbohydrates. Diets severely restricted in carbohydrate may be low in components that we need. For instance,
- Diets low in grain products are likely to be low in B vitamins and minerals. Whole grains are also rich sources of potassium and fiber.
- Low-fat or fat-free milk and yogurt are excellent sources of calcium, protein and riboflavin.
- Vegetables and fruits are rich sources of vitamins, minerals and fiber. They may also have other components with health benefits that are still being discovered.
Some experts stress the importance of eating breakfast and at least two other meals a day to help control hunger. People with insulin resistance or diabetes may need to spread their calories out over a whole day by having small meals and two to three small snacks. (This can also help reduce hunger.)
Related AHA publications: