Exchange plans are used in programs such as Weight Watchers to supply a framework for timing and content of meals as well as portion control.

Foods are separated into various categories such as "carbohydrates" that include milk, fruit, vegetables, and starches. Foods within each category are easily "exchanged" with each other to provide variety and personal choice. Portions of each food are regulated specifically to control calorie, protein, carbohydrate and fat content. A typical daily menu would look something like this -- Breakfast: 2 grains, 1 milk, 1 protein; Lunch: 2 grains, 1 milk, 2 proteins, 1 fruit; etc.

To follow an exchange diet, you'll need a food plan that lists different foods with their exchange equivalents. For example, one slice of bread might be equivalent to ¾ cup of cornflakes or 3 graham crackers. There is no single food plan, and they differ slightly between agencies. If you decide to make the exchange diet a permanent part of your dietary lifestyle, you'll be able to make up your own food plan to accommodate your personal tastes .

• Food exchange plans provide a flexible structure that allows numerous food choices. You're unlikely to get bored, which means you're more likely to stick with the diet.
  
  
• Food exchange plans typically are based on sound nutritional principles that provide adequate amounts of most nutrients.
  
  
• These plans can be easily followed for life, allowing long-term weight maintenance.

• Weight loss is typically slow and gradual, which may discourage some people who feel they have a lot of weight to lose.
  
  
• Food exchange plans require you eat foods from every food group, even if you don't like vegetables.