Fixed-Menu Diet: A fixed-menu diet provides a list of all the foods you will eat. This kind of diet can be easy to follow because the foods are selected for you. But you get very few different food choices which may make the diet boring and hard to follow away from home. In addition, fixed-menu diets do not teach the food selection skills necessary for keeping weight off. If you start with a fixed-menu diet, you should switch eventually to a plan that helps you learn to make meal choices on your own, such as an exchange-type diet.

Exchange-Type Diet: An exchange-type diet is a meal plan with a set number of servings from each of several food groups. Within each group, foods are about equal in calories and can be interchanged as you wish. For example, the "starch" category could include one slice of bread or 1/2 cup of oatmeal; each is about equal in nutritional value and calories. If your meal plan calls for two starch choices at breakfast, you could choose to eat two slices of bread, or one slice of bread and 1/2 cup of oatmeal. With the exchange-type diet plans, you have more day-to-day variety and you can easily follow the diet away from home. The most important advantage is that exchange-type diet plans teach the food selection skills you need to keep your weight off.

Prepackaged-Meal Diet: These diets require you to buy prepackaged meals. Such meals may help you learn appropriate portion sizes. However, they can be costly. Before beginning this type of program, find out whether you will need to buy the meals and how much the meals cost. You should also find out whether the program will teach you how to select and prepare food, skills that are needed to sustain weight loss.

Formula Diet: Formula diets are weight-loss plans that replace one or more meals with a liquid formula. Most formula diets are balanced diets containing a mix of protein, carbohydrate, and usually a small amount of fat. Formula diets are usually sold as liquid or a powder to be mixed with liquid. Although formula diets are easy to use and do promote short-term weight loss, most people regain the weight as soon as they stop using the formula. In addition, formula diets do not teach you how to make healthy food choices, a necessary skill for keeping your weight off.

Flexible Diets: Some programs or books suggest monitoring fat only, calories only, or a combination of the two, with the individual making the choice of both the type and amount of food eaten. This flexible type of approach works well for many people, and teaches them how to control what they eat. One drawback of flexible diets is that some don't consider the total diet. For example, programs that monitor fat only often allow people to take in unlimited amounts of excess calories from sugars, and therefore don't lead to weight loss.

Questionable Diets: You should avoid any diet that suggests you eat a certain nutrient, food, or combination of foods to promote easy weight loss. Some of these diets may work in the short term because they are low in calories. However, they are often not well balanced and may cause nutrient deficiencies. In addition, they do not teach eating habits that are important for long-term weight management.

It is important to choose an eating plan that you can live with. The plan should also teach you how to select and prepare healthy foods, as well as how to maintain your new weight. Remember that many people tend to regain lost weight. Eating a healthful and nutritious diet to maintain your new weight, combined with regular physical activity, helps to prevent weight regain.

Source: National Institute of Diabetes and Digestive and Kidney Diseases