Nutrition Knowledge: Answers to the Top Ten Questions
Nancy Clark, MS, RDTHE PHYSICIAN AND SPORTSMEDICINE - VOL 24 - NO. 10 - OCTOBER 96
With as many sports nutrition ideas as choices in a supermarket, it's no wonder people become perplexed. Sometimes the results from a new study on food can completely contradict what you may have previously heard, leaving you more confused than ever. To help you out, here are some basic questions that I am routinely asked—and their straightforward answers.
1. What's the right balance of carbohydrate, protein, and fat?
If you eat too many carbohydrates, you may deprive your body of protein and fat. The best balance for a sports diet is 60% to 65% of the calories from carbohydrates, 10% to 15% from protein, and 20% to 30% from fat. This means that meals are based on carbohydrates, not made up exclusively of carbohydrates.
Your protein intake should be two small servings per day to build and protect muscles. A few examples of a serving would be 2 tablespoons of peanut butter, 3 ounces of chicken, or 1/2 cup of beans. You should also include three to four servings of calcium-rich foods (such as yogurt or milk) for building strong bones. Also, having a little bit of fat will balance your diet, provide essential fatty acids, and assist with absorption of certain vitamins.
2. Should I stop eating red meat?
Stop eating fatty red meat. Too much fatty meat not only clogs your arteries, but it may also take the place of carbohydrates you could be eating, which can lower stamina.
Lean cuts of beef, pork, and lamb can be easily included in your diet. The Food Guide Pyramid recommends two 2- to 3-ounce servings of lean meat a day for a total of 5 to 6 ounces. Lean meats are excellent sources of not only protein but also iron and zinc, two minerals particularly important for athletes.
Keep portions small. Slice a small piece of lean steak into thin strips, then stir-fry it with veggies and serve with lots of carbohydrate-rich rice. Or add a little extra-lean hamburger to spaghetti sauce.
3. Should I take vitamin pills?
If you are active and have a good appetite, you can get a lot of vitamins in your diet. Unlike an inactive elderly person, who might eat 1,000 to 1,500 calories per day, an athlete may top 3,000 calories. By choosing wholesome foods, then, you can double or triple your vitamin intake. For example, if you drink 12 ounces of orange juice, you'll get 200% of the recommended dietary allowance (RDA) of vitamin C.
If you eat fewer than 1,500 calories per day, one multivitamin and mineral pill might be good. If you do not eat meat, iron and zinc supplements can be helpful. Note that some fortified breakfast cereals and energy bars provide 100% of the RDA for many nutrients.
But you need to eat well even if you take a supplement. Without a doubt, fruits and vegetables are the best sources of important nutrients. The ones with the most vitamins are oranges and orange juice, cantaloupe, strawberries, kiwi, bananas, green and red peppers, broccoli, spinach, tomatoes, carrots, and sweet potatoes. These powerhouse foods provide vitamins and may also guard against aging, cancer, heart disease, and other diseases.
4. Is an energy bar best for an afternoon snack before I work out?
An energy bar is a convenient, but expensive, calorie source. You can get the same energy from snacks such as yogurt, a banana and juice, a bagel, or fig cookies. Find out which foods settle best in your stomach.
The popularity of energy bars has highlighted the importance of eating before exercise. Fueling within an hour before you work out boosts stamina and endurance (1).
5. I don't drink eight glasses of water every day. Is that bad?
You don't have to drink water, per se, to fulfill your fluid requirement. Many foods are water filled: juice, oranges, lettuce, soup, yogurt, milk. Even coffee and tea provide water, but they tend to increase urination.
Because your fluid need is based on the calories you burn, you may need more than the proverbial eight glasses per day. You need 1 mL of water per 1 calorie burned. For an inactive person who requires about 2,000 calories per day, this comes to 2,000 mL, or about 8 glasses. Clearly, athletes who burn off 3,000 to 6,000 calories per day need even more fluids. The easiest way to tell if you are drinking enough is to monitor your urine: It should be clear in color.
6. Which is better to replace sweat losses—water or a sports drink?
Sports drinks are important during endurance exercise like marathons to help replace fluids and energy. This helps prevent both mental and physical fatigue. So if you exercise for more than an hour, a sports drink (or other source of water and carbohydrates) taken during the workout will provide the energy you need. If you are exercising for less than an hour, water is generally fine.
After a hard workout, you can easily replace carbohydrates and fluids with juices. Because sports drinks are dilute for rapid absorption, they are a weaker source of carbohydrates than juice. So you need to drink twice as much sports drink (about 32 ounces) to get enough carbohydrates, about 50 g (200 calories) every 2 hours after exercise (2).
7. How much should I weigh?
Because weight is largely under genetic control, look at your immediate and extended family. Genetics aside, the rule of thumb to estimate appropriate weight is:
This means a 5'8" woman should weigh around 140 pounds, and a 5'8" man, 154 pounds. This formula, though, does not account for bone structure and musculature. So add or subtract 10% if you have a large or small bone or muscle structure.
8. I do lots of fat-burning exercise and don't eat any fat. Why haven't I lost weight?
To lose weight, you have to burn off more calories than you eat. Some people do this by adding exercise. In the process, they lose fat but build muscle—and weigh the same.
Other people exercise but end up eating more. Even though they eat fat-free foods, they get plenty of calories that negate the deficit. Because fat creates a feeling of fullness, people who eliminate fat often tend to feel hungry and continue to eat. Those calories add up!
You might have better success if you include a small amount of fat with each meal. Most female athletes, for example, can lose weight on about 1,600 to 1,800 calories per day. Given that 25% of calories can appropriately come from fat, they can eat 35 to 50 g of fat per day.
9. How do I best gain weight?
To gain weight, you have to consistently eat more calories than when you are maintaining weight. The easiest way to do this is to drink extra fluids like low-fat milk or juices. Cranberry juice is particularly high in calories. Also, the carbohydrates in juices provide lots of energy for muscle-building exercise that helps you bulk up.
You can also eat extra snacks and larger portions at meals. You don't need expensive weight-gain drinks; they are simply high-priced calories-in-a-can. Simply eat and drink 500 to 1,000 more calories per day of wholesome foods.
10. I think my teammate has an eating disorder. What can I do?
Although resolving the problem should be left to professionals, you can tell your teammate that you are worried about her health. For example, mention that she seems unhappy or tired. Or maybe she has a poorly healing injury or can't finish workouts. When you focus on her health and happiness, she may listen. But if you talk about food and weight, she'll likely deny any problem.
Don't expect her to open up right away. Talk to her coach or parents, or give her lists of local resources. (Call the American Anorexia/Bulimia Association, Inc, at  501-8351.) Remember that eating disorders can be life threatening.
Remember: You, your physician, and your nutritionist need to work together to discuss nutrition concerns. The above information is not intended as a substitute for appropriate medical treatment.
Ms Clark is director of Nutrition Services at SportsMedicine Brookline in the Boston area. She is a fellow of the American College of Sports Medicine, a fellow of the American Dietetic Association, and a member of its practice group, Sports and Cardiovascular Nutritionists (SCAN).