Food – The 4 Main Food Groups
To understand human nutrition, food refers to the food that humans eat to survive. Food is composed of any material consumed to give nutrition to an organism. In modern times, food is generally of animal, plant or microbial origin, and includes essential nutrients, like proteins, carbohydrates, vitamins, or mineral ions. The major groups of food include carbohydrates, proteins, fat, vitamins, and minerals.
Carbohydrates are the primary source of energy in plants; they are also used in animal production and may be used as the primary source of food in human diets. Animal products such as meat, dairy products, fruits, vegetables and whole grains provide a variety of carbohydrates. Plants, including legumes, roots, herbs, nuts and seeds contain mainly protein, with vitamins and minerals usually being minor components. The classification of foods according to their carbohydrate content is largely arbitrary; however, plants and animals share many common characteristics in the way they metabolize carbohydrates and in what quantities they accumulate them.
Many factors influence food choices and the amount of carbohydrates ingested per day. One of the major influences of carbohydrate consumption is food choice: people who consume a high volume of complex carbohydrates may suffer from poor nutrition and chronic disease. Therefore, diet and nutrition guidelines must take account of the type and quantity of carbohydrates consumed.
Carbohydrate nutrition is largely affected by the macronutrients eaten and the total daily calorie intake. Typically, the best dietary sources of macronutrients are complex carbohydrates such as grains, vegetables and legumes; good sources of monounsaturated fats are nuts, seeds and nuts oilseeds. Macronutrients vary according to body size and composition. Because some people have more need for carbohydrates than others, and because of the impact of body size on intake, weight loss and management of diabetes are considered important. Obesity and type II diabetes are associated with poor dietary intake of macronutrients and poor glycemic index (GI) ratings of foods. Both lack of dietary fiber and excess calories lead to increased body fat and decreased activity levels, both of which contribute to excess fat accumulation and potential for cardiovascular disease.
The macronutrients to focus on include fat, protein, carbohydrates and vitamins. Oils are considered a good source of fats and unsaturated fats. These fats and oils are used for heat and as cooking aids and in salad dressings. Health experts recommend limiting oils and fats in the diet. Fats and oils are also a good source of essential vitamins A, D, E and K.
Vegetable sources of fibre are legumes (beans, lentils and peas) and nuts. High-fibre vegetables (which include brussel sprouts, carrots, spinach, cucumbers, cabbage and lettuce) provide nutrients and are great for your diet. Nuts are high in protein, but are low in fibre. They can provide some of the following essential nutrients: protein, dietary fibre, unsaturated fats, magnesium and potassium. Nuts are also a good source of salt and fibre.