Eat, Drink & Be healthy

Image Gallery A hamburger provides a full day?s supply of protein, but is it good for you? Protein from leaner meats and from vegetable sources has fewer calories and less saturated fat.

We hear a lot these days about the popularity of high-protein diets, but protein has been studied far less intensively than fats and carbohydrates in relation to long-term health and disease.

Intriguing research on soy has kindled new interest in protein that may eventually yield better information, however, that’s several years away. In the meantime, getting more protein from fish, chicken and vegetable sources, such as beans and nuts, and less from red meat and dairy products is high on the list of healthy eating strategies.

A Basic Human Need

Your hair and skin are mostly protein. Ditto your muscles, the oxygen-carrying hemoglobin in your blood and the multitude of enzymes that keep you alive and active. Proteins are long, intricate chains fashioned from just 20 or so basic building blocks called amino acids. Because our bodies are constantly making new proteins and because we don’t store amino acids as we do fats, we need a near-daily supply of protein.

Some dietary proteins are complete, meaning they contain all the amino acids needed to make new protein. Others are incomplete, lacking one or more essential amino acids. Meat, poultry, fish, eggs and dairy products tend to be good sources of complete proteins, but vegetable protein is often incomplete. That’s why it is important for vegetarians to eat combinations that complement each other, such as rice and beans, peanut butter and bread, tofu and brown rice.

We know from laboratory studies and from the horrible “natural experiments” of war and famine that adults need per day about 8 grams of protein for every 20 pounds of weight, or about 50 grams (about 1.8 ounces) for an adult woman and 65 grams (about 2.3 ounces) for an adult man. You can hit this goal almost without thinking, given the abundance of protein-containing foods. Because it is so easy for Americans to get protein, it’s uncommon for healthy adults in this country to have a protein deficiency.

Aside from the minimum amount of protein needed to keep the body healthy, little guidance is available on the ideal amount of dietary protein. International comparisons aren’t much help because diets around the world tend to have similar amounts of protein. In the average American diet, which we tend to think of as meat-centered, about 15 percent of calories come from protein. In the largely vegetarian, rice-based diets that are common throughout Asia, about 12 percent of calories come from protein. (Rice, which we think of as a carbohydrate, is about 8 percent protein.) Other types of human studies haven’t paid that much attention to protein. Until there’s a good reason to change, a minimum of 8 grams of protein per 20 pounds of body weight is a good guide.