Essentials of Nutrition for Sports

Nitrogen waste is excreted in the urine as either urea or
ammonia.

The digestion of protein releases acids that the body usually

neutralizes with calcium and other buffering agents in the blood. High protein intakes can increase urinary calcium excretion. The effect on calcium balance is controversial since amino acids also increase the efficiency of intestinal absorption.

In the Nurses’ Health Study, women who ate more than 95

grams of protein a day were 20 percent more likely to have broken a wrist over a 12-year period when compared to those who ate less than 68 grams a day.

The relationship of long-term high protein intakes to liver

disease, kidney disease and diabetic ne

phropathy is controversial and

uncertain.

Bad Company

A 6-ounce untrimmed T-bone steak provides 40 grams of high-

quality protein. It also delivers 38 grams of fat, 15 of them saturated—almost three-fourths of the daily allowance for saturated fat.

A pint (16 ounces) of whole milk provides 300 calories; 16 grams

of protein, 24 grams of carbohydrate, and 16 grams of fat. Fat calories account for 47% of total calories. Depending upon the brand, about 60% of fat calories are saturated.

A pint (16 ounces) of fat-free milk provides 172 calories; 16

grams of protein, 24 grams of carbohydrate, and 0.8 grams of fat. Fat calories account for 5% of total calories.

Six ounces of swordfish provides 44 grams of protein but only 9

grams of fat, 2 of them saturated. However, methylmercury levels are high, 1 part per million. Six ounces deliver almost an entire weekly safe allowance of methylmercury.

A cup of cooked lentils has 18 grams of protein, less than 1 gram

of fat, and negligible contaminants.

Allergy

Proteins in food may cause allergic reactions including hives,

cardiovascular collapse, and death.

Relatively common culprits include peanuts and shellfish.

Diabetes

Some evidence shows that protei

ns found in cow’s milk may

play a role in the development of type I diabetes, perhaps on an immune or allergic basis.

Athletic Considerations Protein

Many athletes, particularly those involved in strength training,

believe that to build muscle you need more protein. Almost all Americans get more than enough.

Exercise, not extra protein, is the way to increase muscle size

and strength.

Excess protein does not build muscles. It is either burned as

energy or stored—not as muscle, but as fat.

Endurance athletes have a higher requirement than most body-

builders due to protein breakdown and losses of lean body mass following aerobic exercise.

The FNB adult daily RDA is about 0.75 grams per kilogram

(0.35 gram per pound). Studies support up to a maximum of twice that amount, 1.5 grams per kilogram (0.7 grams per pound), for full-time aerobic endurance athletes.

This increased requirement can be readily met without

supplementation with the high caloric intakes required by athletes. Amino Acid Supplements

Amino acids are the building blocks of protein. If you consume

good quality protein in your diet

, you are probably getting many

times the amounts hyped in most supplements.

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