The idea is that when foods are combined inappropriately, they cannot be absorbed from the intestinal tract. Weight gain is a result of eating patterns, not excess calorie intake.

The food combining diet is based on the chemistry of digestion. According to its advocates, when starches and proteins are combined in meals, they work against each other and cause the digestion process to slow down. This means that not all the nutrients in the food are digested, potentially leading to gastrointestinal problems and weight gain.

The food combining diet is based on the following rules:

• Protein (e.g., meats, nuts, beans) and starches (e.g., bread, pasta, potatoes) should not be combined in meals.
  
  
• In each meal, either a protein or a starch should be combined with a vegetable.
  
  
• Fruits should never be combined with other foods.

In the food combining diet, 70 percent of the foods allowed are fruits and vegetables and the other 30 percent consist of one or two servings of starch such as rice or pasta and minimum amounts of animal protein. Dairy products are prohibited.

Variations of this diet have been around since the early 20th century and have been courting controversy ever since.

• Eating more fruits and vegetables is highly encouraged by most health authorities.
  
  
• Meals that follow this diet have the potential to be lower in calories. Because some proteins and starches are high in calories, restricting your meal to only one of these food types might mean ingesting fewer calories.
  
  
• Weight loss may occur rapidly because of the limits on types of foods allowed (e.g., dairy products, processed foods).

• You might find that you'll miss the traditional "meat and potato" meal. With this diet, you can say goodbye to spaghetti and meat sauce, Asian stir-fry with noodles, and chicken and rice.
  
  
• This diet can be deficient in many nutrients if people don't make sure that they eat a balanced diet. Nutrients that could drop off the radar include protein, calcium, zinc, and vitamins D and B12.
  
  
• The concept of food combining is controversial. In fact, there is plenty of evidence to show that combining foods in the same meal actually enhances the absorption of nutrients. For example, eating oranges (high in vitamin C) with steak has been shown to increase the absorption of iron from that meal.