Carbohydrates, Lipids And Protein Characteristics

Calories come in three main varieties: carbohydrates, lipids/fats and protein. Also known as macronutrients, they serve to provide energy. Per gram, carbohydrates and protein each provide 4 calories, while lipids/fats provide 9 calories per gram. Each macronutrient has distinct characteristics that make it uniquely suited to fulfill important body functions.

Carbohydrates

Carbohydrates are the most abundant organic molecules in nature, and the average person's diet is made up mostly of carbohydrates, which have a wide range of functions beyond serving as your main energy source. As glycogen, which is found in the liver, they also act as a storage form of energy. Carbohydrates are classified based on their structure. Monosaccharides, or simple sugars, include glucose and fructose. Disaccharides include lactose and sucrose. Complex carbs, or starches, are made up of simple sugars strung together to form larger molecules.

Lipids/Fats

Dietary fats, also known as lipids, serve as a concentrated form of energy. They also help your body digest fat-soluble vitamins, such as vitamins A, D and E. In addition, lipids can be converted into substances such as prostaglandins, which modulate pain and inflammatory responses. Hormones, including testosterone and estrogen, are derived from lipids, which are categorized based on the structure of their fatty acids. Saturated fatty acids contain no double bonds. These fats are found mainly in animal products, as is cholesterol. Unsaturated fatty acids are found in vegetable oils. Trans fats are a type of man-made lipid found in margarine and vegetable shortening.

Protein

Protein is unique among the macronutrients in that it contains nitrogen. Lipids and carbohydrates, on the other hand, are made up of atoms of oxygen, carbon and hydrogen. The presence of nitrogen in protein makes it an essential nutrient. Your body can turn protein into fat or carbs, but because these macronutrients do not contain nitrogen, the reverse does not hold true, and protein is therefore required in the diet. Proteins are made of different combinations of 20 amino acids. In your tissues, protein is required for growth and repair. It also maintains muscle. As an enzyme, protein helps power the chemical reactions in your body.

Recommendations

Because protein, lipids and carbohydrates perform such a variety of essential bodily functions, assuring you consume adequate amounts of each macronutrient is important for optimal health. Based on a 2,000-calorie diet, the USDA recommends 50 g of protein, 300 g of carbohydrates and 65 g of fat. When choosing fat sources, take care to minimize saturated fat and cholesterol, as these fats are associated with an increased risk of certain diseases.