The food you eat every day provides the nutrients you need to survive. These food components include the macronutrients – protein, carbohydrate and fat – that offer calories as well as play specific roles in maintaining your health. Micronutrients, such as vitamins and minerals, don’t act as an energy source but do serve a variety of critical functions to ensure your body operates as optimally as possible.
Protein
Protein, found in meats, milk, eggs, soy, legumes and whole grains, supplies your body with a pool of amino acids, the building blocks of this nutrient, and is a component of all your cells. As part of muscle, bone and skin tissue, it supports your body’s structure. It also repairs these tissues if they become damaged and provides antibodies and other immune cells to cope with inflammation and infection. Your dietary protein helps create hormones and enzymes to keep your cellular machinery running smoothly. Finally, this macronutrient can serve as a fuel source if other calorie sources are unavailable.
Carbohydrate
The principal purpose of the carbohydrates in the foods you eat is to provide energy to fuel your activities. The energy comes from the breakdown of starches and sugars to their simplest forms, which your cells can then convert to usable power. Although protein and fat can also supply you with energy, your cells prefer the calories from carbohydrates, and, in fact, some organs – your brain and kidneys, for example – have a specific need for a carbohydrate fuel source. Some carbohydrates pass through your system undigested, and this dietary fiber offers no calories but can improve your gastrointestinal health.
Fat
Fat supplies more than twice the calories per gram as protein or carbohydrate and, as such, is a highly concentrated source of energy your body stores for later use. It provides structure to cell membranes and cushions your internal organs to help prevent damage to tissues. Fat serves as a vehicle for delivering fat-soluble vitamins, and it can also store these nutrients as insurance against a deficiency. Dietary fats can come from both animal and plant sources, with plant-based foods, nuts and fish offering a healthier version of this nutrient than that found in animal sources such as beef and full-fat milk products.
Vitamins and Minerals
Vitamins and minerals are small-molecule food components you need in varying amounts to support your health. Vitamins are involved in energy production, wound healing, eye and skin health, bone formation and immunity. Minerals provide structure to your skeleton, maintain your cardiovascular health, help transmit nerve impulses and serve as a cofactor for enzymes throughout your body. Consuming a well-balanced diet with a variety of fruits and vegetables helps ensure you have plenty of these nutrients in your body.
Considerations
Food can provide compounds other than macronutrients and micronutrients that might improve your health. For example, phytochemicals are plant-based molecules that can serve as antioxidants, anti-inflammatories and, potentially, anti-cancer agents. Brightly colored fruits and vegetables are rich in phytochemicals. Consuming them as a component of food is preferable to taking supplements, as their specific actions and possible toxicity at high doses is under investigation.
