A netter recently informed me that the Atkins diet was effective in losing his weight. In each of the two week sessions, he successfully lost more than ten pounds without feeling too much uncomfortable.

How could this happen? The Atkins diet has been criticized by all kinds of nutrition societies and has gone bankrupted after Dr. Atkins died. Market has proved that the Atkins diet is a failure. So the netter’s story puzzles me.

When we eat something, to some extent, we intake nutrients because human body (except for stomach and intestine) doesn’t care about the shape or texture of foods. All the body wants are nutrients, and cells work on these small molecules.

Human body needs macronutrients: carbohydrate, protein, and fat; and micronutrients: all sorts of vitamins, minerals, and other chemicals. In modern time, we can supply the body with quite a lot of micronutrients by taking pills, but we still have to gobble down a big chunk for macronutrients. Thus, most diet formula focus on the different combination of macronutrients.

The Atkins diet is a high-protein, low-carbohydrate diet with a liberal fat intake. It assumes that a high intake of protein will satiate the body while providing enough body building nutrients. This is partially true, but not the whole story.

Dietary proteins, when digested and absorbed, are decomposed into different types of amino acids, and these acids are reconstructed in the body to build necessary proteins. Glucose, usually derived from dietary carbohydrate, is the main energy source for human body. Fat is a second important energy source but given an abundant supply of glucose in modern diet, fat only stores energy. Fat is also a critical component in maintaining cell structure.

If dietary carbohydrate intake is limited, human body may quickly deplete the glucose reserve (such as glycogens in the liver and muscles) and start to burn fat in muscle cells. On the other hand, glucose may be generated through gluconeogenesis in which proteins are converted to glucose. So low-carb high-protein diet may change the way human body utilizes the energy.

But the liver has limited capability to process proteins. The byproduct during this conversion, the urea, has to be excreted through kidney. So high protein diet may overwhelm the liver and kidney. Protein poisoning such as nausea, diarrhea, or even death, is possible for those high protein diets. For example, an arctic explorer, Stenfasson, once tried the protein only foods for a week and got seriously sick, although he did loose more than 10 pounds.

Speaking of high-protein low-carbohydrate diet, one cannot avoid examining the Inuit paradox. For a long time, these arctic living people only ate fat and meat with little vegetables. Apparently they survived and were not tremendously obese, and the prevalence of heart disease was not higher than that of modern western people. What was the secret behind their diet?

Although Dr. Atkins may not derive his diet from the Inuit diet, he did use the Inuit diet as the proof for his high protein high-fat diet. However, there are still substantial differences between the Atkins diet and the Inuit diet.

First is the fat content. People who adopted the Atkins diet consume a lot saturated fat and processed vegetable oil which has high concentration of trans fat, while fat in the original Inuit diet contains much unsaturated fat (e.g., fish meat). Inuit people also ate the fat in a relatively raw form which provides them essential nutrients such as vitamin C.

Second, modern people spend much less time in physical activity while the original Inuit people were basically hunter gathering tribe. Inuit people needed such a energy dense diet to support their heavy physical activity, while for modern people, the weight loss though the Atkins diet is essentially a disease-inducing process.

In a sense, Inuit people had adapted to the high protein high fat diet, while modern people are adapted to high carbohydrate diet. Try to switch diet style may work temporally, but only temporally. People cannot stay on the Atkins diet for too long. The myriad of side effects caused by the Atkins diet will teach dieters that the Atkins diet is not a good idea, which is proved by the market itself.

Dr. Atkins diet has been out of fashion, and now the south beach diet is coming, so do other exotic diets such as negative calorie diet. No matter what diet you are trying, you have to remember human body needs a balanced diet. Restricting your total energy intake may be better than consuming brand named weight losing bars.