Dr. Nelson, I've been reading a lot about high protein, low-carb diets, like Dr. Atkins' and The Zone. Should I try one?

Protein is a critical component to our body's functioning. Protein is important for synthesizing enzymes and hormones, maintaining fluid balance, and assisting in vital functions such as building antibodies against infection, blood clotting, and scar formation. In addition, our muscles, bones, cartilage, skin, hair, and blood are all made in part from protein.

In general, Americans consume more than enough protein to maintain all of these functions—and then some. In fact, most Americans consume enough excess calories from protein, (and fat and carbohydrates, too) that are not converted to energy or otherwise used by the body and are therefore stored as fat.

Protein is found mostly in animal products such as meat, cheese, milk, fish, and eggs, but it can also be found in vegetarian combinations such as rice and beans, corn and beans, and tofu or soy products as well. Many people may think that because protein helps to build muscle, that extra protein will give an added boost to muscle mass and strength. However, there is no scientific evidence that this is true unless a person is malnourished to being with. In reality, it is progressive strength training—not extra protein—which will increase muscle mass and strength safely and effectively.

With that said, not only is extra protein not beneficial to gaining muscle mass or strength more rapidly or an effective means for weight loss, it can also be harmful to your body. When you cut carbohydrates drastically and make up the difference with protein, you force your body to utilize an inferior fuel source; these are fat metabolites called ketones. Your kidneys are then thrust into overdrive to flush these ketones out of your body, as they are toxic. As a result, you can lose an impressive amount of weight fairly quickly, but it is not fat you are losing! When your kidneys are ridding your body of these toxic ketones, you also lose a significant amount of water, and since one pint of water weighs about a pound—the scale looks good. And perhaps even better because people tend to eat a little less in general on these diets. The Atkins' diet is a ketogenic diet that works on this principal.

But the unfortunate reality is that water isn't all you have lost, and it is unlikely that you have conquered the real demon: fat. In the process of losing the "weight" (water), you have lost muscle and calcium from your bones. Also, the diet has put a lot of strain on your kidneys, and it has left you dehydrated which means stress on your heart muscle, too. Worse yet, a ketogenic diet will likely produce adverse side affects on how you feel. Many women feel weak and dizzy after a week or so on this type of diet. Bad breath and other problems may also develop. And in the long run, when the body's water is restored, most people find that they have not lost much weight, if any at all. It is important to note that The Zone diet is much more moderate and is not ketogenic. There is no research that confirms that a thirty percent protein diet helps with weight loss, but the author does advocate a diet low in simple sugars which is in fact helpful.

The best diet for you to follow for long-term weight loss is one that is rich in fruits, vegetables, and whole grains and as few processed foods as possible. Try to get the majority of your protein from fish, tofu, and the leanest cuts of meats. To keep your bones strong, get calcium from cottage cheese, low-fat milk, green leafy vegetable, hard cheeses, or calcium fortified orange juice. Although you will need to follow a low-fat diet, remember that some fat is necessary to maintain a properly functioning body.

by Miriam Nelson, PhD
Created October, 2000