The sheer number of reducing diets and "miracle" weight-loss products is mind-boggling. We survey some of this variety below. No matter how you approach it, permanent weight loss requires effort, may require substantial changes in eating and exercise habits, and is never accomplished overnight.
Almost any reducing diet that reduces caloric intake will result in weight loss if it is rigidly followed. However, such diets are hard to sustain, and serious weight maintainance problems immediately appear when the diet is abandoned and no new healthy eating patterns have been established to replace ones that resulted in weight gain in the first place. In order to be recommendable, a reducing diet should encourage sensible weight loss, and encourage healthy eating and exercise habits both during and after 'dieting' is complete.
Low Fat Diets
As dietary fats carry almost twice as many calories as carbohydrates and proteins, reducing dietary fat intake seems a natural approach to weight loss. In fact, the current USDA Food Pyramid recommends a low fat diet for healthy living. As the name implies, a low fat diet involves careful regulation of the amounts of dietary fats one may eat, reducing fat intake to 30% of one's total intake with only 10% of total calories in saturated fat form. Both obvious (butter and spreads, fried foods, mayonnaise, etc.) and subtle sources of dietary fat (many restaurant-prepared foods are surprisingly high in fat)must be identified and restricted for this dietary approach to work.
A common misconception dieters have regarding low fat diets is that they can eat as much low fat food as they want and still lose weight. There is nothing magical about eating a low fat diet, however. Such a diet can help with weight loss only when it succeeds in reducing the total amount of calories a person eats. Dieters who increase portions of low fat foods end up eating as many calories as they did before and fail to lose weight. All calories count.
It is a good idea to use judgment and to keep nutritional principles in mind while selecting foods to eat for a low fat diet. Some so-called low fat foods are really only low fat versions of high fat foods. Low fat ice cream, for example, may be low fat in comparison to premium ice cream, but it is still essentially a high fat item that shouldn't be eaten while on a low fat diet. Also, some packaged low fat foods are made with all sorts of unpronounceable chemicals. As always, the best low fat food choices will be unprocessed, naturally low fat foods, such as fresh fruits and vegetables.
Low fat diets are one thing, and very low fat diets are another. Recommended by some medical doctors (including Dean Ornish and John McDougal) as a part of a balanced plan for heart disease rehabilitation, very low fat diets require limiting fat intake to 5% or 10% of total calories. Diets this low in fat tend to be high in starches and carbohydrates. While not harmful for most adults, this type of diet may not be suitable for those with diabetes or insulin resistance. A very low fat diet is difficult to follow over the long term as it requires people to avoid tasty foods they like to eat. Some dieters give into cravings for higher fat or protein foods and lapse off their diet, sometimes abandoning it all together. Suggestions for managing cravings and dietary lapses are described below.
Low Carbohydrate Diets
Low or restricted carbohydrate diets such as the Atkins Diet have become popular because they can produce rapid weight loss. Such diets work as do any reducing diets, by severely reducing calorie intake. Unlike other restrictive diets, low carbohydrate diets encourage a blatantly unbalanced approach to caloric restriction, reducing not only carbohydrate intake but also intake of fruits, vegetables, legumes and grains. By restricting carbohydrates and encouraging meat eating, low carb diets end up encouraging people to eat far more saturated fat than is healthy. Such a diet is not sustainable over the long term.
Low carb diets do nothing to prepare people to maintain their weight loss once they have achieved their goals. Low carb dieters thus tend to regain weight they have lost once they resume their normal diets.
The South Beach Diet takes a different approach to carbohydrate restriction than the Atkins diet. Like the Atkins diet, the South Beach Diet's first phase restricts eating of carbohydrates, producing rapid weight loss. However, the diet's second and third phases reintroduces 'good' carbohydrates and promote moderate consumption of a wide variety of nutritional foods. The South Beach diet thus combines the weight loss benefits of the unsustainable low carbohydrate diet with the healthy and nutritional diet necessary for sustained weight maintainance and health.