The Catabolic Diet was based on what the author, Victor Lindlahr, M.D., called (back in 1920s) "reverse calories" or "negative calories." The foods that are allowed in the diet are claimed to burn more calories than they provide the body. If the "catabolic foods" require more energy to digest than they provide, it can mean only one thing: they create negative energy balance.
What is energy balance? Generally, it takes precisely matching caloric intake to caloric expenditure to maintain proper energy stores. Depending on energy storing or spending prevalence, the body can be in only two states: catabolic and anabolic.

The anabolic system is activated during negative energy balance. As soon as the negative energy balance occurs, this system increases food intake and decreases energy expenditure to regain lost energy stores. It is trying to return the body to the energy-saving mode.

The catabolic system is activated during positive energy balance. This system decreases food intake and increases energy expenditure. So only a positive energy balance activates the genuine catabolic system, which seriously contradicts the Catabolic Diet theory.

But this doesn’t mean that the Catabolic Diet theory doesn’t work; it only means that it works in a manner quite different from what the advocates claim.



The Diet’s Claim:

  • Catabolic foods contain what may be called reverse calories. When mixed with regular fattening foods, catabolic foods make them less fattening, by destroying their fat before it can be stored.
  • You can indulge in 1/3 of your menu as regular (anabolic) foods if you have 2/3 from catabolic foods.
  • Catabolic foods are all very low in calories. When we add up the daily caloric value of the catabolic diet, the three pounds of catabolic foods total only an average of 600 calories.
  • Most catabolic foods have a very high water content.
  • The foods allowed in the diet are very high in vitamins and minerals.
  • The diet is very easy to stick to: There is little cooking, no fuss, no bother and is a perfect diet for on-the-go eaters, or people who often eat out in restaurants.
  • There's a list of substitutes so the diet is very flexible.
  • Adherence to the diet helps you decrease the risk of many types of cancers, including colon and rectal cancer.
The Facts:
Though dieters have claimed success while on the Catabolic Diet, factors other than calorie-burning foods, such as the low-calorie, high water content of the foods allowed, also contribute to weight loss. The diet could also have negative health effects, as the energy stored in muscle as well as fat are also tapped. Technically, catabolism refers to something that applies to the overall basic processes in the body's cells, not the properties of foods.

The Medical Lowdown:
Catabolism occurs when complex molecules are broken down into smaller, simpler molecules with the release of energy. Simply put, it occurs when the body weight is decreasing because of calorie restriction, exercise, fever or even emotional stress. Catabolism occurs during the major metabolic cycle -the Krebs cycle -- as well as during cellular respiration, during the breakdown of sugars stored in the liver and muscles and also during digestion. Catabolism does not target fat exclusively; the body's muscles and other tissues are also targeted. This is a major concern of doctors, especially when patients become so ill that the body is wasting away.

A Closer Look at Foods and Digestion:
During digestion, the amount of energy spent is small -- for all foods. Proteins and carbohydrates yield 0.6 percent of available energy. That is, available after the food is chewed, salivated, swallowed, treated with the enzymes, etc. Fats yield even less -- about 0.1 percent.
Another aspect of the diet is to consider how the energy yielded by a food is being used: If we burn a piece of beef with fire, the energy will be yielded exclusively as heat. Believe it or not, almost the same thing is going on within our insides. There's no way a cell can tell where molecules came from-- cabbage, spinach, bacon, or eggs -- it can't distinguish the origins.

Truth or Fiction?
If the catabolic diet works, it works before the digestion is over. This being the case, it's simple to tell what foods will work better than others - those that are harder to chew, with lower so-called energy density, high-fiber, and those that are served raw.
If the dieters' statements are true, Dr. Lindlahr's patients who are eating three pounds of food a day lose more weight than those patients who were fasting.

most of this info was from dietandbody.com