Sports Nutrition News From The Academy of Nutrition and Dietetics
The Athlete’s Kitchen
Copyright: Nancy Clark MS RD CSSD Nov 2012
The Academy of Nutrition and Dietetics (formerly the American Dietetic Association; the nation's largest group of food and nutrition professionals) recently convened in Philadelphia (Oct., 2012). The following highlights from that convention may shed new light on ways for you to optimize your sports diet and manage your weight.
Protein: How much is enough?
Many athletes believe more protein is better. Not necessarily true, according to exercise physiologist Doug Paddon-Jones from the University of Texas Medical Branch. Research subjects who ate a 30-gram dose of protein (about 4 ounces of meat) had similar rates of protein synthesis as those who ate a 90-gram dose (~12 ounces of meat, i.e., a big steak). Because the body does not temporarily store extra protein as muscle, about 60 grams of the protein got “wasted” (or rather, burned for energy or stored as fat). Yet, if you eat only 10 grams of protein at breakfast (1 egg + 1 white), you may not have eaten enough to maximally stimulate muscle synthesis. Paddon-Jones recommends athletes target about 30 grams of protein at three meals per day. That means, cut your hefty dinner steak into thirds and enjoy two-thirds of it the next day at breakfast and lunch!
Although 30 grams is the number often mentioned by researchers, Paddon-Jones reminds us this is not an exact science. Protein research is incredibly expensive; few researchers are able to do dose-response studies to precisely determine the number of grams of protein needed per pound of body weight. Hence, Paddon-Jones suggests athletes simply enjoy a moderate portion of protein-rich foods at each meal.
He also recommends you eat protein after you exercise, so your muscles will have the tools they need to do the building and repairing that peaks in the next 3 to 5 hours. “Mind you, following this strategy will not make a massive difference in your musculature, but it may optimize muscle maintenance. This could make a meaningful difference over the course of a year, particularly for athletes over 30 years old who slowly lose muscle as a normal part of the aging process.”
Enjoying an even distribution of protein throughout the day has another benefit: you'll feel less hungry all day. For yet-unknown reasons, eating protein-rich foods for breakfast contributes to greater satiety than protein eaten at other times of the day. Research suggests a higher protein breakfast can result in consuming 200 fewer calories at dinner. Theoretically, that's enough to lose 20 pounds of fat in a year! How about boosting your breakfast with more Greek yogurt, cottage cheese, and omelets?
Weight Management: How much exercise is enough?
If you want to lose weight temporarily, you don't have to exercise; you “simply” need to create an energy deficit by eating less food. (Think about people in the hospital who lose weight without exercise.) But if you have already lost a lot of weight and want to maintain that fat-loss (and help minimize fat-regain), you need to be active for about one hour a day. According to obesity researcher Dr. Jim Hill, “Unfortunately, that's the price a person who has lost 70 pounds needs to pay for having been obese.”
Dr. Hill suggests there is a yet undefined “sweet spot” where just the right amount of exercise (not too much, not too little) enhances fat loss. As many frustrated runners have learned, too much exercise forces the body into starvation mode and the traditional weight loss ruleto knock off 500 calories per day to lose one pound of fat per weeka myth. The less you eat (or the more you run), the more your body down-regulates to conserve energy and your metabolic system adapts. The body has a very complex system that makes weight reduction difficult.
While any type of exercise is good for weight management, lifting weight and doing other forms of strength training help maintain muscle mass. Dr. Brenden Gurd of Ontario suggests high intensity interval training can contribute to fat loss, particularly abdominal fat. Plus, you’ll effectively improve your fitness in less time!
Weight and Taste Buds
Weight gain is related to not only too little exercise, but also to eating too much food. Why do some runners routinely overeat? According to Dr. Beverly Tepper of Rutgers University, the answer might be related to their taste buds! About 30% of the population has a genetic variation in bitter taste that results in a preference for the taste and texture of high fat foods, such as creamy salad dressings, cheese, and ice creamas well as spicy hot foods. Combine this with our enticing food environmentvoila, overeating! When compared by body mass index (BMI, a ratio of weight and height), fat-preferring women have a higher BMI (30 vs. 24; obese vs. average physique) as compared to women with a different version of this gene.
When presented with a buffet lunch (that encourages overeating), genetic “fat lovers” need to muster more dietary restraint to consciously choose foods that are lower in fat. Otherwise, they may eat 88% more calories than usual, while those without the gene will consume “only” about 38% more calories. (Buffets can be dangerous!)
In a three-day food experiment during which women ate a standard breakfast (OJ, yogurt, toast) and then selected their lunch and dinner, the genetically predisposed “fat lovers” chose more added fats (butter, salad dressing), cakes, and pies, while the others preferred more fruits and vegetables. Perhaps obesity prevention programs could include genetic screening so these people can be taught to better manage our food environment?
Cooking tip: Mushrooms have an “umami” (meaty, savory) flavor that allow them to easily substitute for meat. Taste-testers equally enjoyed tacos made with 100% beef, 50% beef with 50% mushrooms, or 20% beef with 80% mushrooms. How about adding more mushrooms to your next beef stew, spaghetti sauce, or meatballs to save calories and saturated fatas well as help save the environment? According to the Center for Science in the Public Interest, for every two pounds (1 kg) less beef we eat, we spare the environment about 60 pounds (27 kg) of greenhouse gasses. This adds up; we don’t need more super-storms like Hurricane Sandy.
Nancy Clark, MS, RD, CSSD (Board Certified Specialist in Sports Dietetics) counsels both casual and competitive athletes at her office in Newton, MA (617-795-1875). Her Sports Nutrition Guidebook and food guides for new runners, marathoners, and soccer players offer additional information. They are available at www.nancyclarkrd.com. Also see www.sportsnutritionworkshop.com.