Food is any material eaten to provide nutrition to an organism. The word ‘food’ could mean any number of things, from plant matter to animal matter, and may be in any combination thereof. Food is generally of animal, plant or microbial origin, and is made up of necessary nutrients, including proteins, carbohydrates, vitamins, or minerals, with some remaining unneeded substances for supporting the organism’s existence. Humans have eaten food from all around the world since ancient times, when people first started keeping records of what they ate and how much of it they ate. Although the kinds and amounts of food available to modern humans are often limited by scarcity, we can still access natural food sources around the world, from wild greens and nuts, to preserved fruits and grains, to commercially produced foods that are both nutritious and convenient.

In this paper, we investigate the nutritional content of food, considering the three food groups – carbohydrates, proteins and fats – as representative foods. Each food group has its own recommended daily allowance of calories, so that a balanced diet is established which gives the greatest percentage of nutrients to each group. For example, a food that provides 20% of a person’s calories (a ‘sugar load’) would be classified as a food group in the carbohydrate range, while a food that provides twice that (a ‘fiber load’) would be classified in the protein group.

Carbohydrates provide fuel for the body and are obtained from cereals, breads, pasta, rice, beans and nuts. Some plants, such as rice, provide proteins and some vitamins and minerals as plant materials. Fats provide essential oils that are carried through the bloodstream and are necessary for nutrition. The average adult should eat about five servings of carbohydrates and protein per day, although the quantity of each varies by individual, height, activity, body size and diet.

Some fats are soluble in water and other fluids and have no dietary value. Fats are needed for energy production by the body, but too much fat or too little can cause obesity and other health problems. Some fats that are considered good dietary sources are unsaturated fats that occur in nuts, avocados and nuts spreads, olive oil, sunflower and seed oils, and butter. Unsaturated fats are found in fish, nuts, seeds, nuts spreads, palm nuts and mayonnaise.

The third main food group is carbohydrates. Carbs are the basic building blocks of food. They provide energy and starch for the body to use. Three main types of carbohydrates are simple sugars, complex carbohydrates and whole grains. Most people get their carbohydrates from fruit, vegetables, legumes (beans) and whole grain breads.

The fourth major food group is fats. Fats are necessary for the body’s health but can be bad for the health if eaten in large quantities. Fats come from animal sources such as dairy products, spreads, palm nuts, peanuts, beef fat, pork and poultry fat. To avoid fats, look for foods that are high in fiber such as nuts, seeds, olives and raw vegetable oils. For example, instead of eating a burger with its fat, choose a salad with a lot of vegetables and a little healthy oil instead.