The Essential Functions of the Five Major Nutrients

Nutrients are the substances found in food that are essential to the human body and boost biological activity. They are classified into proteins, fats, carbohydrates (sugars, dietary fiber), vitamins, minerals, and nutritions, and perform vital functions. The phrase “you are what you eat” has been around for centuries, but it has taken decades of research to determine exactly what nutritions to eat to be as healthy as possible. Water is the most important essential nutrient; it participates in many of the body's vital functions and delivers other essential nutritions to cells. To ensure you get enough water, make sure each meal is accompanied by 1 cup of milk (or 1 serving of another type of dairy).

Fruits and vegetables are low in fat and contain important vitamins and minerals that help prevent disease, as well as fiber that can lower cholesterol, keep the gut healthy, and aid digestion. You should aim to eat at least five servings of fruits and vegetables a day. Fresh, frozen, canned, or dried fruits and vegetables all count towards your five a day. Check labels and choose low sugar and salt options.

Starchy foods, such as potatoes, bread, rice, and pasta, should make up about a third of what you eat. They are a good source of energy and essential fiber, calcium, iron and vitamins. Gram for gram, starchy foods contain less than half the calories in fat. Try not to add extra fat to starchy foods by adding butter, oil, spreads, cheese, or jam—that just means adding more calories.

Dairy products and dairy alternatives are good sources of protein and vitamins. They also contain calcium, which helps keep our bones healthy and strong. Semi-skimmed, skimmed and 1% fat milk contain less fat than whole milk, but still provide you with protein, vitamins and calcium. Dairy-free milk alternatives include soy milk and nut milks; if you choose dairy-free milk, opt for sugar-free varieties that have been fortified with calcium.

Try using a strong-tasting cheese such as ripe cheddar; the strong flavor means you can use less without sacrificing flavor and therefore reducing fat. Legumes are things like beans, peas, and lentils. They are a good source of fiber, vitamins and minerals and are very low in fat. They count for your five a day but only as one serving no matter how much you eat.

Legumes are great for increasing the volume of things like soups, stews, and meat sauces; they add extra flavor and texture which means you can use less meat. This reduces the amount of fat you eat and also means that your money will go further since legumes are usually cheaper than meat. Other plant-based protein sources include tofu, bean curd, mycoprotein and Quorn; they're protein-packed, low-fat options that can be used instead of meat in most recipes. Fish is a great source of protein, vitamins and minerals; try to eat at least two servings of fish a week with one being rich in oil (one serving weighs about 140 g). Choose between fresh frozen or canned fish; oil-rich fish such as salmon and mackerel contain omega-3 fatty acids that keep our hearts healthy as well as being a good source of vitamins A and D.Whitefish includes fish such as haddock flounder coley cod skate and hake; it is low in fat contains important vitamins and minerals and is an excellent alternative to meat. Choose fresh frozen or canned whitefish but remember that smoked fish or pickled canned fish can be high in salt so always check the label before buying. It is best to steam bake or grill fish; fried fish especially battered fish have more fat. Quiches and flans contain eggs but can be high in fat and salt so eat them less often. Meat is a good source of protein vitamins and minerals; it is one of the main sources of vitamin B12 an important vitamin found only in animal foods such as meat and milk. It's important to know how to cook handle meat safely. Some fats are healthier than others but they all have a lot of calories; limit them in your diet to help maintain a healthy weight. Water low-fat milk sugar-free beverages including tea coffee count; choose sugar-free options instead of sugary drinks.