By Food provides many benefits, including sustenance, cultural significance, economic stability, and mental stimulation. It also plays a role in our health.
Eating a balanced diet is important for our health. We need a wide variety of foods to get the nutrients we need. The Australian Guide to Healthy Eating groups foods into 5 food groups.
Proteins
Protein is one of the three primary macronutrients that provide energy for the body. The body uses proteins to build, repair and maintain tissues and organs. Proteins are made of amino acids, which are linked together in long chains. Some of the 20 different types of amino acids can be made by the body, but nine must come from food (they are called essential amino acids). Good sources of protein include nonfat yogurt, tilapia, chicken breast and peanut butter. Plant foods such as beans and nuts are also good sources of protein. Proteins can be classified as complete or incomplete, depending on whether they contain all the essential amino acids. Animal products and soy are complete proteins, while most plant foods are incomplete. The best sources of complete proteins are fish, skinless poultry and lean meat.
Carbohydrates
Carbohydrates are the body’s main source of energy. They are also found in foods that are delicious, comforting and satisfying. A healthy diet includes both complex carbohydrates (starches) and naturally occurring sugars. Added sugars provide empty calories and lack vitamins, minerals and fiber that are important for good health.
Complex carbohydrates are found in grains, legumes and starchy vegetables such as potatoes and corn. They are also found in fruits and milk. Added sugars can be found in processed foods, syrups and sugary drinks. Naturally occurring sugars include monosaccharide and disaccharide sugars, which are found in vegetables, fruit, milk and honey.
The body uses carbohydrate to get energy for all cells in the body, especially the brain. If the body does not use all the glucose it needs right away, it is stored in the liver and muscles as glycogen for later use. Carbohydrates are also a source of tryptophan, which is used to make serotonin (the mood-enhancing chemical in the brain). A diet rich in carbohydrates helps people feel full and may help prevent high blood sugar, heart disease and diabetes.
Fats
Fats supply energy to the body and help keep us feeling full. They also add flavor and satisfaction to food. They make baked foods moist and flakey, fried foods crispy and creamy ice cream smooth and delicious. Fat is an important part of many of our favorite foods, including butter, oil, nuts, seeds, avocados and fish.
Although fat has gotten a bad rap, it performs several vital functions in our bodies and in the diet. It stores energy, transports fat-soluble vitamins and contributes to the structure of hormones and cell membranes.
However, too much dietary fat can be unhealthy. A gram of fat provides 9 calories, more than twice that of carbohydrates or protein. It is therefore essential to eat a variety of healthy fats, such as mono- and polyunsaturated fats, while limiting unhealthy fats, such as trans fats. This helps to maintain a healthy weight and decreases heart disease risk. It also reduces cholesterol, blood sugar and blood pressure levels.
Minerals
Minerals are naturally occurring substances with a specific chemical composition and a characteristic crystalline structure. Minerals are also the building blocks of rocks such as granite or marble.
Minerals may be identified by their colour, cleavage, tenacity and other properties. Cleavage is the ability to break into flat surfaces with smooth, even splits. A mineral’s tenacity is its resistance to being crushed. The hardness of a mineral is determined by its crystal structure and how the atoms are arranged within it.
Most minerals are found in foods, but some are only required in small quantities for human health. For instance, selenium (Se) is important for normal immune function. However, in the US, daily dietary Se intake has been decreasing due to the use of North American wheat which has less Se than UK wheat.
Minerals are essential nutrients and we need to be sure that our diets contain enough of them to keep our bodies healthy. If you are at risk of a mineral deficiency, it is important to see your doctor and discuss this with a dietitian. Multivitamin/mineral supplements are also an option if your diet isn’t providing enough of the recommended minerals.
Vitamins
The body needs 13 essential vitamins to perform many vital functions. Eating a balanced diet of whole-natural foods should provide most of the vitamins you need, though vitamin supplements are sometimes necessary to ensure that your nutritional requirements are met.
Fat-soluble vitamins are absorbed with the fats you eat, and they stay in your liver and other tissues for months until needed. The most common fat-soluble vitamins include vitamin A, vitamin D and vitamin E. A lack of vitamin A can lead to blindness, while a deficiency of vitamin D causes rickets, which affects the bones and results in soft, weak bones.
Water-soluble vitamins circulate in the bloodstream, and the kidneys regulate levels by shunting excesses out of the body in urine. The eight B vitamins (thiamin, riboflavin, niacin, pantothenic acid, biotin, vitamin B6, vitamin B12 and folate) help release energy from carbohydrates, fats and proteins and are involved in several other bodily functions.
Vitamin C helps heal wounds, support blood vessels and form and maintain healthy teeth and bones. It also helps the body absorb iron from food. Sources of vitamin C include citrus fruits, berries and leafy vegetables, tomatoes, potatoes and fortified cereals.