Results and Risks:Mayo

Results

Initially, when you follow a low-carb diet you may lose more weight than if you followed a low-fat, low-calorie diet. However, this advantage slowly decreases after the first six months. After one year, the amount of weight loss is about the same between the two diets.

Four factors contribute to weight loss with low-carb diets:

• Loss of water weight. When you initially decrease your carbohydrate intake, your body burns glycogen. Glycogen contains large amounts of water, so burning glycogen leads to the release of water and increased urination, causing weight loss.
• Decreased appetite. Studies suggest that a low-carb diet decreases appetite, but why this occurs isn't clear.
• Increased feeling of fullness. Low-carb diets are higher in fat and protein. Fat and protein take longer to digest, which makes you feel fuller longer.
• Reduced calories. Most low-carb diets reduce your overall calorie intake because they strictly limit the variety of foods you can eat. Carbohydrates — including bread, pasta, rice, cereals, milk, most fruit and any sweets — usually provide over half of people's daily calories. On a low-carb diet, however, carbohydrates are limited or avoided, thus leading to a significant reduction in calorie intake.

Theoretically, in order to maintain weight loss if you do lose weight, you need to continue the program. But a low-carb diet doesn't appear to be easier to maintain than any other diet. Studies comparing low-carb diets and low-fat diets found that after a year, people dropped out of both diets at similar rates. This suggests that the low-carb diet, like so many diets, is no easier to stick to long term.

Risks

No one knows the long-term health effects of low-carb diets. Though some studies have looked at the benefits and risks, none has been conducted over a long enough period to show whether these diets increase the risk of health conditions that develop over many years, such as heart disease, cancer, and kidney or bone problems.