We should eat the right number of calories in order to remain active. Eating or drinking too much will put on weight. On the other hand, eating and drinking too little, will be the cause of weight loss. The average man needs around 2,500 calories a day (10,500 kilo joules). The average woman needs 2,000 calories (8,400 kilo joules). We should eat as per our required calories.Eating wide range of foods can ensure getting a balanced diet which is very essential for the nutrition of the body.