Your body needs macronutrients and micronutrients in order to survive. Macronutrients, which include protein, fat, carbohydrates and macrominerals are required in relatively large quantities. Micronutrients, such as vitamins and trace minerals, are required in smaller amounts. Fiber is a non-digestible carbohydrate that is also essential to human health.
Carbohydrates
Carbohydrates provide your body with its main energy source. Carbohydrates are broken down in your body to create glucose, which all of your cells and organs use. Starchy foods such as fruits, potatoes and yogurt are high in carbohydrates. Other sources include cheese, beans, grains and vegetables. Carbohydrates provide 4 calories per gram and should make up between 45 and 65 percent of your daily caloric consumption, according to the University of Illinois at Urbana-Champaign’s McKinley Health Center.
Protein
Your body uses protein to repair damaged cell tissue, bolster growth, support immune function and synthesize enzymes and hormones. Your digestive system breaks the protein you eat into its basic building blocks, called amino acids. Foods such as meat, chicken, tofu, dairy products, eggs, nuts and beans are good sources of protein. Protein provides 4 calories per gram and should make up between 45 and 65 percent of your daily caloric consumption.
Fat
Fat should not be feared. It is a necessary nutrient that your body uses to support normal growth, cushion sensitive internal organs, maintain cell membranes and aid in the absorption of vitamins. However, fat is higher in calories than protein or carbohydrates. It provides 9 calories per gram and should make up between 20 and 35 percent of your daily caloric consumption.
Fiber
Fiber is a type of carbohydrate, but your body doesn’t digest it. It doesn’t provide any calories, vitamins or minerals, but instead passes through your gastrointestinal system and is excreted intact. Despite this, fiber is a vital part of a healthy diet. It acts as a natural laxative and helps prevent constipation. Fiber’s ability to help food pass through your intestines may decrease your exposure to cancer-causing substances produced by your intestinal bacteria. Fiber is present in whole grains, fruits and vegetables.
Vitamins
The word “vitamin” is a combination of the Latin word “vita” and the word “amine.” Casimir Funk, originator of the term, believed that all vitamins were vital for life and derived from substances called amines. He was right about the first part and wrong about the second - not all vitamins are amines. Vitamins are organic compounds that your body requires, but can’t synthesize. Some vitamins are water-soluble, meaning that excess amounts are excreted in your urine. Vitamin C and the B vitamins are water-soluble. Fat-soluble vitamins do not dissolve in water, and excess amounts are stored in your fat. The fat-soluble vitamins are A, D, E and K.
Minerals
Minerals don't provide calories, but they do contribute to the formation of many substances your body needs. Like vitamins, your body cannot synthesize minerals. Macrominerals are those required in daily dosages that can be measured in grams. You only need trace minerals in minute quantities. The macrominerals are iron, calcium, potassium, chloride, sodium and phosphorus. Microminerals include copper, cobalt, zinc, iodine, fluorine and manganese.
References
- The Merck Manual; Overview of Nutrition; July 2007
- McKinley Health Center, University of Illinois at Urbana-Champaign McKinley Health Center; Macronutrients: the Importance of Carbohydrate, Protein, and Fat; March 2008
- Elmhurst College Virtual Chembook; Overview of Metabolism; Charles E. Ophardt; 2003
