Food is composed of a wide variety of nutrients. Some are essential to the body because it cannot make them on its own. The others are called non-essential because the body can produce them on its own with the essential nutrients that it is provided. Nutrients are divided into two main groups, macronutrients and micronutrients.
The prefix "macro" suggests a large amount thus macronutrients are the ones the body needs to be supply in great amounts. They make up the majority of an individuals diet. The body needs these for growth, maintenance and activity. They are especially important to teens because we are doing a lot of all three of the above. Macronutrients consist of three main groups:
Role: Carbohydrates are the main source of energy. They are the main fuel important for athletes and brain function. They supply the much-needed short-term energy used for executing tasks high in intensity and last for shorter durations of time. This is because it is easy for the body to turn it into energy. Composition: Carbohydrates are all made of and broken down by the body as sugar. Carbohydrates can be broken down further into groups:
§ Monosaccharides
- eg. glucose (blood sugar), fructose (sugar found in fruit)
§ Disaccharides
- eg. sucrose (table sugar)
§ Polysaccharides
- eg. starch and fiber like potatoes, bread, pasta
Monosaccharides and disaccharides are collectively known as simple sugars while polysaccharides are known as complex sugars and take longer to turn into energy.
*A calorie is the unit of measurement for the potential energy the food supplies
Role: Proteins support the growth and repair of muscles, ligaments, tendons, bones, nails, skin, and hair. It is also responsible for producing enzymes, hormones, and antibodies. Composition: All proteins are made of amino acids. There are 22 amino acids. 9 are essential (can not be made by the body) and 13 are non-essential (can be made by the body). Proteins can be further divided into two groups:
§ Complete proteins (made of the 9 essential amino acids)
- eg. Red meat, poultry, milk, cheese, fish, eggs
§ Incomplete proteins(made of the 13 non-essential amino acids)
- eg. Nuts, legumes
(a pescitarian should compensate for not eating land animals by eating for example more fish, milk, and cheese to be sure they receive enough complete proteins)
Recommended intake: about 15% of daily caloric intake (based on a 2000 calorie diet), contain 4 calories per gram.
Role: Fats, in their recommended values are part of a healthy diet. Fats supply long- term energy for activities that entail lower intensity done over a long duration of time. They also insulate the body and protect its organs. Composition: Fats are all made from fatty acids but not all fats are the same. Fats can be broken down into groups:
§ Trans fats- are also known as partially hydrogenated oils. They are produced industrially and should be avoided completely. They can be found in fried foods, baked goods, and shortenings.
§ Saturated fats – produce cholesterol. High levels of saturated fats lead to high levels of low-density-lipoprotein (LDL "bad cholesterol) that build up in and clog arteries. Examples of common sources are milk, butter, beef, and pork.
§ Unsaturated fats- there are two categories of unsaturated fat. Monounsaturated fat increases levels of high-density-lipoprotein (HDL good cholesterol) lowers only low-density-lipoprotein (LDL bad cholesterol) and lowers risk of coronary heart disease (examples of sources-olive oil, canola oil, avocados, almonds, pecans). HDL cholesterol seeks out the LDL cholesterol and takes it to the liver to be disposed of. Polyunsaturated fats lower both good and bad cholesterol and are not thought to contribute to or protect the body from heart disease (examples of sources- sunflower oil, corn oil).
§ Essential fatty acids- (Omega 3, Omega 6, and Omega 9) are a class of unsaturated fat. The body must consume 3 and 6 but can produce 9 on it's own. They are thought to protect against heart disease and are necessary for healthy cardiovascular, reproductive, immune, and nervous systems. They can be found in walnuts, pumpkin seeds, dark leafy green vegetables, and oily fish.
Recommended intake: 15-30% of daily caloric intake (based on a 2000 calorie diet), trans fat should be avoided completely, less than 10% of daily intake of fat should be saturated fat, unsaturated fats should make up the majority of total consumed fat. Each gram of fat contains 9 calories.
Micronutrients are to the nutrients that are only needed by the body in small values. This group consists of:
§ Vitamins- organic substances ingested with food that trigger reactions in the body
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