Food is any material food consumed to supply the organisms with required nutrition to maintain their existence. In the sense of human consumption food consists of foodstuffs that are consumed to satisfy human appetite or satiation, to keep up with the amount of food a person eats, or for health reasons. In simple words food is food meant for human consumption. In the contemporary period food is generally of animal, plant or fungi origin, and includes essential nutrients, like proteins, carbohydrates, vitamins, or other minerals.
Although all the foods we consume are rich in calories and nutrients and can sustain our needs for a number of days, there are certain foods that are rich in more than others in terms of nutrition and absorption levels. Generally speaking animal foods, such as meat, milk, butter, cheese, eggs, and poultry, contain the highest percentage of nutrients and are highly recommended dietary sources for optimal nutrition. On the other hand, plant foods, including cereals, pulses, whole-grain breads, fruits, vegetables, and legumes (beans) are extremely low in calories and so absorb fewer nutrients than animal foods. This is why animal-based proteins such as red meat are rich in protein but low in fat and therefore considered unhealthy for good nutrition; whereas plant-based proteins, especially legumes such as beans, are rich in fat but absorb higher percentages of nutrients due to their greater acidity.
The food pyramid is a useful tool to guide people on eating a healthy balanced diet by providing an estimate of the nutrient content of different food groups. It is a two-tier system, with food intake per body weight, and food groups represented by colours denoting the level of each nutrient needed by the body. For instance, fruits are the most balanced food group, orange being the most powerful colour indicating the highest concentration of vitamin C. A good way to start eating a well balanced diet is to include fruits in all the meals, and to eat some dairy products in case one doesn’t want to completely eliminate meat and other animal-based foods from the diet. Some experts even recommend that pregnant women and young children under six years old should not eat sugar-rich foods, which they should ideally replace with fruit juices or water, and may also eat small portions of cereal or grain bread for breakfast and lunch.