The theory is that certain carbohydrate-containing foods cause a higher insulin response than do others and that insulin promotes fat storage. Combinations of foods can alter how quickly the blood glucose rises. Dietary fat or protein, eaten with the carbohydrate food, can slow the rate of glucose absorption. Using the glycemic index as a guide results in screwy lists of allowed and forbidden foods. Okay foods are meats, margarine, cheese, and chicken.
Bad foods are carrots, rice, watermelon, bread, and potatoes.
For example, one day's menu plan adds up to 1200 calories. The forbidden foods list and the unsubstantiated claim for energy metabolism have little or nothing to do with the actual weight loss. Then there is the problem with ketosis. When the body's fuel is largely fat, the metabolic end-products are ketone bodies, for example, acetone. That causes bad breath, headaches, weakness, and potential kidney and liver damage.