Ketonic diet is also known as Atkins diet. Dr. Atkins was a cardiologist who first developed his diet in the early 70's. It is based on a low carb diet.

The diet is based on the theory that overweight people eat too many carbohydrates. Our bodies burn both fat and carbohydrates for energy, but carbs are used first. By drastically reducing carbs and eating more protein and fat, our bodies naturally lose weight by burning stored body fat more efficiently.

By restricting carbohydrates drastically, the body goes into a state of ketosis, which means it burns its own fat for fuel. A person in ketosis is getting energy from ketones, little carbon fragments that are the fuel created by the breakdown of fat stores. When the body is in ketosis, you tend to feel less hungry, and thus you're likely to eat less than you might otherwise. However, ketosis can also cause a variety of unpleasant effects (such as unusual breath odor, weakness and constipation) in a small number of people.

As a result, your body changes from a carbohydrate-burning engine into a fat-burning engine. So instead of relying on the carbohydrate-rich items you might typically consume for energy, and leaving your fat stores just where they were before (alas, the hips, belly, and thunder thighs are popular fat-gathering spots), your fat stores become a primary energy source. The purported result: weight loss.

In slightly more detail, consider what happens when you eat a high-carbohydrate meal. Sugar from the carbohydrate quickly enters the bloodstream. To keep the blood sugar from rising too high, the body secretes insulin. Insulin allows the extra sugar to be stored in the liver and muscle as glycogen, but these stores are rapidly filled to capacity. The insulin then converts any extra sugar to fat - the stuff we're trying so hard to get rid of.

For most people, the carb consumption must be no more than 40 grams a day for this biochemical mechanism to occur. Although exercise isn't stressed, the Atkins theory holds that some people will need to add physical activity for ketosis to kick in. People are urged to supplement with vitamins, since they won't be getting enough of them from sources such as vegetables and fruits. Amount of carbs translates to three cups of loosely packed salad or two cups of salad with two-thirds cup of certain cooked vegetables a day.

There are no exceptions to these rules during the first two weeks because low-carb consumption (no fruits and only a few leafy green vegetables) is supposed to jump-start the weight-loss biochemical activity of the diet. You're not counting calories (in fact, you may be eating more calories than you were before).

Later, the carb allowance is increased in the form of fiber-rich foods, but you do not return to eating refined sugar (by the teaspoonful or in desserts), milk, white rice, white bread, white potatoes or pasta made with the dreaded white flour. Those remain on a lifelong list of forbidden pleasures.

The diet does allow for adding fruits, vegetables, and whole-grain foods after the two-week induction period.

Then, over time, the transition from weight loss to weight maintenance is made by gradually increasing carbs so long as gradual weight loss is maintained.

Exercise in all phases as part of a healthy lifestyle is now emphasized more than when the diet was first introduced.

Health experts, anyway, remains concerned about the long-term safety of the diet. This diet requires more testing. The diet is very prescriptive, very restrictive, and limits half of the foods we normally eat, so you must know, it's not healthy to be on this diet for more than 3 months. It should not be considered as a way of life, but if you are looking for weight loss, yes, it works.

Diet:
* Sets few limits on the amount of food you eat but instead severely restricts the kinds of food allowed on your plate: no refined sugar, milk, white rice, or white flour
* Allows you to eat foods traditionally regarded as "rich": meat, eggs, cheese, and more
* Claims to reduce your appetite in the process.
* On this diet, you're eating almost pure protein and fat. You can consume red meat, fish, fowl, and regular cheese (not "diet" cheese). You can cook with butter, have mayo with your tuna, and put olive oil on your salads.

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