People do lose weight on high-protein, low-carbohydrate diets, though the weight loss is due to water loss and reduced calories, not to lower insulin levels as the authors claim. Even so, nutrition experts do not recommend these diets. First, the weight loss is difficult to maintain over the long term. Second, there is some evidence that these diets may increase the risk of coronary heart disease (CHD) and kidney damage—conditions for which people with diabetes are already at high risk.
Diets high in protein tend to be high in fat, particularly saturated fat. For example, the Atkins diet and Protein Power provide about 20% to 25% of calories from saturated fat. In comparison, the American Diabetes Association recommends that less than 10% of calories come from this type of fat.
Diets high in saturated fat can raise blood cholesterol levels, which in turn increase the risk of CHD. In a study of the Atkins diet, published in the Journal of the American Dietetic Association in September 1980, people who followed the diet for eight weeks experienced an increase in blood cholesterol levels, even though they had lost weight.