Protein ping-pong - updates - amount of protein need in ideal diet unknown

Better Nutrition, Feb, 2003

Over the decades, experts have bounced back and forth on the amount of protein needed in the ideal diet, with no consistent advice for confused consumers.

But finally, amid the controversy, nutritionists at the October 21, 2002 meeting of the American Dietetic Association in Philadelphia basically admitted that they really don't know how much protein North Americans need.

The public has been bombarded with conflicting advice on the benefits--or dangers--of carbohydrates, fats and protein. But protein illustrates the problem best.

Nutritionists in the 1960s told the public they would be healthy if they ate lots of meat. Then, over the next two decades, health experts promoted high-carbohydrate diets and warned against eating too much protein.

When the low-carbohydrate, high-protein Atkins' diet debuted 30 years ago, and again after its recent resurgence, experts came out strongly against it, saying protein--along with fat--is what is killing us.

Too much protein may even hurt the kidneys and weaken bones, says the American Heart Association. Excess protein reduces the body's ability to absorb calcium after just six weeks, concludes a study in the August 2002 issue of the American Journal of Kidney Diseases.

And the weight loss associated with high-protein diets may actually be simple fluid loss, some experts say.

Even so, the tide again seems to be ebbing toward ingesting a higher level of protein.

So where are we now? That depends on whether or not you're trying to lose weight.

The latest general nutrition guidelines avoid hard and fast numbers for the percentages needed from the major food groups, leaving that choice to the consumer. Protein recommendations now range from as low as 10 percent to as high as 3 5 percent of total nutrient intake.

Dieting? Several new studies suggest that dieters who exercise and maintain moderately higher levels of protein may lose more weight in the form of fat, sparing more muscle mass than a high-carbohydrate weight-loss regimen.

Some experts now say that protein foods--more than carbohydrates or fat--lead to feelings of fullness and may help dieters stick to their programs longer.

And dieticians warn that the percentage of protein may have to be higher on a low-calorie diet because a minimum of 50 to 80 grams of protein--or 200 to 320 protein calories--is needed to support lean tissue.

But the latest wisdom still opposes a strict high-protein diet that recommends 120 grams of protein daily because it ignores the body's need for carbohydrates.

The Atkins' diet, for instance, limits total carbohydrate intake to just 20 grams a day. But carbs are a major source of fiber and should constitute at least 50 percent of daily consumption.

Now you're up to date--or at least that's the story this month. Check back with BN regularly to stay on top of the latest protein and carbohydrate studies.