By now, you've certainly heard the testimonials. If you want to lose weight, look good, or simply have more energy, you should be on a high protein diet. The words of Dr. Atkins and Barry Sears are becoming as commonplace as daily bread, or, more specifically, daily meat. Whether they are a fad or not, high protein diets have developed a lifestyle following.
The buzz surrounding these diets has prompted some to wonder about basic information about protein: What is it? What does it do? Do these diets really work? Read below to learn more about the basics of this key nutrient.
So what is protein, anyway?
Your body uses protein to build and repair itself. Amino acids are the building blocks of proteins. Of the 20 amino acids that humans need, 11 are made by the body and are considered nonessential. The remaining nine must be obtained from food and are therefore essential - it is 'essential' that these amino acids are part of your diet.The 'protein quality' of a food is determined by its amino acid make-up. Foods that contain all nine essential amino acids are referred to as 'complete proteins'. These are usually animal products such as meat, milk, cheese, poultry, and fish (soybeans are the exception). Tofu, tempeh, and other foods made from soy are also considered 'complete.' More commonly, plant proteins (such as rice, grains, and nuts) are deficient in one or more essential amino acids or are 'incomplete.' But if you eat them together, like having peanut butter on whole wheat bread or eating beans and rice, your protein is 'complete.'
Protein requirements
The government mandated Recommended Dietary Allowance (RDA) for protein is based on body weight. Take a minute to calculate your protein requirement, and you may be surprised by the amount you require compared to the amount you take in. The RDA is as follows:Multiply .36 grams by your weight in pounds. This will equal the grams of protein needed each day. For example, a woman who weighs 118 pounds would require 43 grams of protein each day (.36 x 118 = 43 grams).
The average American easily reaches and often exceeds this protein requirement without even being on a high protein diet. Actual daily protein consumption ranges from 88-92 grams for men and 63-66 grams for women.
However, there are many conditions in which extra protein is needed, including childhood/adolescence (growth), pregnancy, lactation, intense strength and endurance training, and some diseases such as AIDS and cancer. Elderly persons also may require additional amounts of protein.
For the general population, the body does not need or use excess protein. Any excess protein can hang around and become a burden for the kidney and liver.
Schools of thought
One big concern that nutrition professionals have about high protein diets is that they tend to be higher in animal fats, which can increase cholesterol levels and raise the risk for heart disease, cancer, stroke, and diabetes over time. The low amount of carbohydrates allowed from fruits, cereals, vegetables, or other food groups can lead to deficits in vitamins, minerals, fiber, antioxidants, and other nutrients that fight cancer and maintain bone density.Nutrition experts say that high protein diets may not be harmful for most healthy people over the short term. They're wary, though, since they believe the "science" used to promote these diets is based on unpublished research or unproven and potentially invalid studies.
Dr. Alice Lichtenstein, Tufts nutrition professor and vice-chairman of the American Heart Association's Nutrition Committee, recently spoke to the media about the problems with these diets. "These diets prescribe lots of animal proteins and those tend to be high in saturated fats, which increases cholesterol. And because these diets restrict the intake of fruits and vegetables, that compounds the increases of LDL [bad] cholesterol and lessens the benefits of weight loss on the reduction of blood pressure," she said in an Oct. 9 HealthScout interview.
Lichtenstein offers some practical advice. "Follow a diet high in fruit, vegetables, and whole grains, and consume low-fat dairy, meats and fish," she said. Of course, the other part of the equation is to maintain exercise so that food consumption is balanced with energy expenditure.
Parting words on protein
If you are thinking about jumping on the high-protein bandwagon, make sure you understand that it carries some risk. Aside from the potential long term problems (heart disease, osteoporosis, and kidney/liver damage), these diets can severely crimp a healthy lifestyle and mindset. Planning your food for the entire week and avoiding alcohol might not be such bad things but wouldn't you just rather exercise and eat what and when you want?You don't have to be an expert on nutrition to eat healthfully. However, be curious and question what you read. If only someone could make sensible eating flashy and turn it into a best selling diet book...
Tara Mardigan, a Registered Dietitian, is a combined Nutrition and Masters of Public Health student at Tufts.
