Each gram of fat gives about 9 Calories of energy. Every gram of protein gives only almost 4 Calories of effective energy (the equivalent to carbohydrates). Alcohol is absorbed completely, and each gram contributes 7 Calories of energy.
The 9 Calories per gram of fat exemplify the most compact form of food energy. 3500 Calories of energy, in practical terms, is the quantity that could be required daily by an active young athlete. This can be obtained in almost a pound of pure fat. Knowing this fact, the hoax of the high-energy capsules, often marketed to target athletes, becomes rather obvious. Because one teaspoon of fat weighs around 5 grams, it gives no more than 45 Calories. Presuming that a high-energy capsule weighed 5 grams (definitely jumbo for a capsule), its caloric share would also be at 45 Calories. And that’s the energy available in about half of a usual cola drink.
Athletes, having high energy requirements, might find it helpful to include extra amount of fatty foods. This is especially true for the young contender in energy-demanding sports, like soccer, basketball, and distance running, who can bring down the total bulk of his or her diet by having larger amounts of fat and still match the body’s energy needs. Nut-spreads such as
peanut butter and vegetable oils, margarine, and nuts all add up concentrated calories without an unneeded addition of bulk or saturated animal fats.
Carbohydrates give 4 Calories of energy per gram, less than half that of fats. However, sweets and starches may impart plenty calories to the diet and are often regarded “fattening.” They do offer a significant amount of energy, since they are drawn from refined carbohydrate sources such as table sugar and highly milled flour. They likewise have minimum water and fiber content, and therefore, comparatively concentrated sources of calories. Common
desserts like cakes, pies and pastries, which are customarily regarded as being
carbohydrate foods, really contain huge quantities of shortening, which is fat and accounts for many of their caloric contribution. Some carbohydrate foods, like noodles, spaghetti, potatoes, and rice, give fewer calories, unless consumed in very large quantities or in combination with fatty foods.
A few vegetables, like lettuce, celery and cabbage, hold large sums of carbohydrate in the form of
cellulose, but give very little energy. Humans can’t digest cellulose, and it only lends bulk to the diet. The fact is, foods high in cellulose are great for people who must cut back their caloric intake. But, due to their high bulk and low caloric content, they’re ineffective for those who have high energy requirements.
As referred earlier, protein is the least effective of the three energy sources in the diet. While protein provides 4 Calories of energy per gram, the mode in which it is metabolized tremendously brings down the availability of the energy it furnishes.
