Protein: How Much is Too Much?
Fri, 4 Nov. 2011 - 6:41 p.m. MT
Credit: ARA Staff - American Running Association
Protein provides the building blocks for tissues, enzymes, and hormones that are needed for activity and movement. It also plays a role in immune function. It only accounts for between 10 and 15 percent of your energy during exercise, however, and so it can be ingested sparingly; let’s look at why that’s actually advisable for maximum positive effect. “Sparingly” is a relative term but we use it because most people, particularly Americans, get far more protein than their body needs. The USDA defines a serving size of meat as just three ounces (a deck of cards). This is far less than what you’d ever receive in a restaurant. As food manufacture has become inexpensive in the last few decades, serving sizes have gone up even further. Consequently, most people don’t really realize how much protein they’re consuming—in many cases, over-consuming. Still, protein is essential for fat oxidation during exercise. It increases oxygen delivery and strengthens muscle contractions. It prolongs muscle-glycogen stores, sustains aerobic metabolism, and helps repair damaged tissue after hard workouts. So how much protein does an athlete need to consume daily? Meeting requirements. The RDA for protein is .35 grams per pound of body weight. Athletes require more protein than sedentary people. But there is a clearly defined ceiling for even the most active among us: studies have shown that consuming more than .9 grams per pound per day of protein provides no additional health benefits. Some of the excess protein may be converted to glycogen for storage in the liver, but the rest is converted to fat for storage. In your Foundation mesocycle, during which you’re training largely to increase aerobic capacity, aim for .5 to .6 grams of protein per pound of body weight. A 165-pound athlete would need 80 to 100 grams daily (320 to 400 calories). You’ll likely find when you do the math that you are meeting or exceeding this requirement already. In that case, reduce your protein intake to better control overall calorie intake. Carbohydrate, by comparison, should be consumed at rates of 2.5 to 3 grams per pound of body weight. Carbs ought to make up 65 percent of total calories—and preferably from whole grains, fruits, and vegetables. Our 165-pound athlete, training 5 to 8 hours per week, would therefore consume 410 to 500 grams (this is 1,640 to 2,000 calories). At half a gram per pound of body weight, protein makes up just 13 percent—and healthy fats 22 percent (60 to 75 grams) —of your daily diet. Many popular nutrition programs advise as high as 25 to 30 percent of total calories for protein. But by basing the calculation on known optimal numbers in grams per pound of body weight that your body can absorb, you ensure that you will properly process and use the protein for energy, recovery, and developmental needs. Otherwise, it is very easy to overeat protein. Because your carbohydrate portions make up the majority of your diet, the proper amount of protein at meal time in comparison can look oddly small. Protein-rich foods are very dense; carbohydrate-rich vegetables and pastas are much bulkier. A 100-gram serving of pasta takes up much more room on a plate than a 100-gram serving of chicken. Going by eye, you are prone to the bias of “normal”-looking plates you see in restaurants or saw as a child at home.
Fiber first. Remember too that some forms of calories are more filling than others. Protein is the most satiating nutrient, followed by high-fiber grains, fruits, and vegetables. The Atkins diet once used this idea to great effect—at least in its marketing—but the diet has largely been discredited since. The far better option if you’re trying to eat less is to go for high fiber, which is extremely filling but passes through your system (providing myriad other health benefits).
The 2010 edition of the U.S. Dietary Guidelines for Americans frowns on eating 10 percent or more of calories from saturated fat and more than 35 percent from fats overall. So the Atkins diet, which is 64 percent fat calories overall and 18 percent saturated fat, is ill-advised. The idea behind Atkins is that insulin tells your body to make and store fat. When you restrict carbs, your insulin level goes down and you can burn body fat. Replacing refined carbs with high-fiber fruits and vegetables—and even unsaturated fats, as from fish and avocado—is a far better way to restrict insulin production than consuming huge quantities of saturated fat.
Protein should take its place as the accompaniment to carbs in each meal and snack. To determine how much protein you eat at meals, use the information on food labels and/or analyze your diet at websites such as www.fitday.com or www.sparkpeople.com. A word about the other extreme. Many vegetarians who think they eat well are surprised to learn how little protein plant foods offer. For example, a petite vegetarian athlete who needs at least 55 grams of protein per day might base her meals on these plant-proteins for the day: Breakfast: a dollop of hummus (4 g protein) on toast Lunch: a vegetarian burger (13 g) Dinner: a quarter-cake of tofu (9 g). That totals only 26 of the recommended 55 grams of protein. She gets a bit more protein from the grain foods and veggies that round out her meals, but she would be wise to double those protein portions. Food for Fitness by Chris Carmichael, 2004, G.P. Putnam’s Sons, New York, NY, pp. 41-44, 103-127 The Athlete’s Kitchen, “Protein and Athletes” by Nancy Clark, MS, RD, 2008 (RUNNING & FITNEWS® May / June 2011 • Volume 29, Number 3)