There are 3 macronutrients that the human body needs in order to function properly.

(A) CARBOHYDRATES:

Carbohydrates are your body's main source of energy. When
you ingest carbohydrates your pancreas releases a hormone
called insulin
Insulin is very important because:
- It grabs the carbohydrates and either stores them in the muscle or stores them as fat.
- It grabs the amino acids (protein) and shelters them inside the muscle cell for recovery and repair.
Most people that are overweight and are in low fat/high carbohydrate diets got into that condition because they are eating an overabundance of carbohydrates. Too many carbohydrates cause a huge release of insulin. When there is too much insulin in the body, your body turns into a fat storing machine. Therefore, it is important that we eat no more carbohydrates than necessary and that we eat the right amount of carbohydrates.
Now that we have talked about the importance of having just the right amount of carbohydrates, let's talk about which are the best sources of carbohydrates.
Carbohydrates are divided into complex carbohydrates and simple carbohydrates. The complex carbohydrates give you sustained energy ("timed release") while the simple carbohydrates gives you immediate energy. It is recommended that you eat mainly complex carbohydrates throughout the day except after the workout where your body needs simple carbohydrates in order to replenish its glycogen levels immediately, something that will aid faster recuperation and rebuild of the muscle. Below is a list of good sources of carbohydrates:

There are two types of carbohydrates: Complex and Simple

Complex Carbohydrates:

• Starchy

Oatmeal
Sweet potatoes
Potatoes
Rice
Pasta

• Fibrous

Beans
Broccoli
Cauliflower
Green beans
Lettuce
Mushrooms
Pepper
Spinach

Simple Carbohydrates:

Apples
Bananas
Grapefruit
Grapes
Oranges
Pears
Pineapple

(B) PROTEINS:

Every tissue in your body is made up from protein (i.e., muscle, hair, skin, and nails). Proteins are the building blocks of muscle tissue. Without it, building muscle and burning fat efficiently would be impossible. Its importance is paramount. Protein also helps to increase the metabolism. It also makes the carbohydrates timed release, so you get sustained energy throughout the day.

Everybody that is involved in a weight training program should consume about 1 gram of protein to 1.5 grams of protein per pound of lean body mass (meaning that if you are 200 lbs. And have 10% body fat, you should consume at least 180 g of protein since your lean body mass = 180 lbs.).
Good examples of protein are eggs, chicken breast (skinless) turkey, lean red meats, Whey Protein and tuna.

(C) FATS:

All the cells in the body have some fat in them. Hormones are manufactured from fats. Also fats lubricate your joints. So if you eliminate the fat from your diet, then your hormonal production will go down and a whole array of chemical reactions will be interrupted. Your body will then start accumulating more body fat than usual so that it has enough fat to keep on functioning. Since testosterone production is halted, so is muscle building. Therefore, in order to have an efficient metabolism we need fat.

There are three types of fats:

1. Saturated Fats: Saturated fats are associated with heart disease and high cholesterol levels. They are found to a large extent in products of animal origin. However, some vegetable fats are altered in a way that increases the amount of saturated fats in them by a chemical process known as hydrogenation. Hydrogenated vegetable oils are generally found in packaged foods. In addition, coconut oil, palm oil, and palm kernel oil, which are also frequently used in packaged foods and non-dairy creamers are also highly saturated.

2 -Polyunsaturated Fats: Fats that do not have an effect in cholesterol levels. Most of the fats in vegetable oils, such as corn, cottonseed, safflower, soybean, and sunflower oil are polyunsaturated.

3 - Monounsaturated Fats: Fats are good fats that have a positive effect on the good cholesterol levels. These fats are usually high on the essential fatty acids and may have antioxidant properties. Sources of these fats are Fish Oils, Virgin Olive Oil, Canola Oil, and Flaxseed Oil.

Twenty percent of ones calories should come from good fats. Any less than 20% and your hormonal production goes down. Good sources of fat are canola oil (1 tablespoon), natural peanut butter (2 tablespoons), olive oil (1 tablespoon), flaxseed oil (1 tablespoon), and fish oils (1 tablespoon). Each serving size contains approximately 14 grams of fat.

(D) WATER
Water is by far the most abundant substance in our body. Without water, an organism would not survive very long. Most people that come to me for advice on how to get in shape, almost always underestimate the value of water.
Water is good for the following reasons:

- Over 65% of your body is composed of water (most of the muscle cell is water).
- Water cleanses your body from toxins and pollutants that would get you sick.
- Water is needed for all of the complex chemical reactions that your body needs to perform on a daily basis. Processes such as energy production, muscle building, and fat burning require water. A lack of water would interrupt all of these processes.
- Water helps lubricate the joints.
- When the outside temperature is up, water serves as a coolant to bring the body temperature down to where it is supposed to be.
- Water helps control your appetite. Sometimes when you feel hungry after a good meal this sensation indicates a lack of water. Drinking water at that time would take the craving away.
- Cold water increases your metabolism.
In order to know how much water your body needs a day, just multiply your lean body weight by .66. This would indicate how many ounces of water you need in a day.