They are the main sources of energy for the body and are vital for building muscle. How the body converts food to fuel relies upon several different energy pathways. Having an understanding of these nutrients can help you exercise and eat for improved sports performance.
Simple carbohydrates
Simple carbohydrates come in various forms of sugar, such as glucose and sucrose (table sugar), are simple carbohydrates. They are small molecules, so they can be broken down and absorbed by the body quickly and are the quickest source of energy. They quickly increase the level of blood glucose (blood sugar). Fruits, dairy products, honey, and maple syrup contain large amounts of simple carbohydrates, which provide the sweet taste in most candies and cakes. Simple carbohydrates get absorbed very quickly and give rise to increase in blood sugar level immediately. Sugars and starches supply energy to the body in the form of glucose. Glucose is the energy source for red blood cells and the brain, central nervous system. Fruits, vegetables, grains and milk are the main sources of carbohydrates. It is recommended that 60 percent of total energy be distributed by carbohydrates.
Complex carbohydrates
Complex carbohydrates are composed of long strings of simple carbohydrates. Because complex carbohydrates are larger molecules than simple carbohydrates, they must be broken down into simple carbohydrates before they can be absorbed. They tend to provide energy to the body more slowly than simple carbohydrates because they need to be broken down, but still more quickly than protein or fat. Because they are digested more slowly than simple carbohydrates, they are less likely to be converted to fat. They also increase blood sugar levels more slowly and to lower levels than simple carbohydrates but for a longer time. (Better for exercising) Complex carbohydrates include starches and fibers, which occur in wheat products (such as breads and pastas), other grains (such as rye and corn), beans, and root vegetables (such as potatoes).
Protein
Mainly found in body skin, muscles, organs, and glands. Protein is required to help the body repair cells and make new ones. Protein produces hormones, enzymes, antibodies and maintains alkali-acid balance. Protein plays an important role in growth and development during childhood, adolescence and pregnancy. Animal foods such as meat, fish, poultry, eggs and plant foods like beans, peas, nuts, seeds, grain, and soybeans are the sources of proteins. The United States RDA is 0.8g/kg or 0.4g/lbs. This is 80g protein per day if you weigh 200lbs. But this recommendation is based on studies done on average, sedentary people. The minimum if you train hard is 1g protein per pound of body-weight per day. That’s 200g daily protein if you weigh 200lbs. You’ll reach this amount easily by eating a serving of protein source with each meal.
Fats
They are the most concentrated form of energy and are needed throughout your life, in right amounts. They make certain vitamins available for the body, they cushion vital organs and help to maintain body temperature. Intake of fats and oils high in saturated fatty acids are to be kept low. (Saturated fats have been linked to high levels of bad cholesterol more than cholesterol increases cholesterol itself) Monounsaturated fatty acids found in vegetables, nuts, olive oil, peanuts, and canaola oil are effective in reducing bad cholesterol without affecting good cholesterol. Recommended total fat intake is 20 to 35 percent of calories for adults.



