If we want to do our jobs and study in daily life, we always need adequate energy to support these activities. If our bodies are always tired without any obvious reasons, we will be rather worried. In order to keep our bodies strong and healthy, we need to maintain a kind of healthy diet in our daily life so as to supplement essential nutrients and energy for ourselves.

Generally speaking, we should eat fruit, vegetables, staple food, meat, fish, eggs, dairy products and so on for three meals each day. It is necessary for people to arrange the food correctly and grasp the moderate intake so as to prevent malnutrition and overnutrition. For example, when we have dinner three times a day, we should also eat fruit for three times. Dairy products are also essential for each dinner. As the most basic nutrients, sugar and carbohydrates are the main sources for the body energy. The operation of all the internal organs inside the human body has to consume sugar. Complex carbohydrate is very beneficial to the body, as it will not be consumed rapidly. Various kinds of food like rice and bread contain the nutrient. 

Except the main foods, the subsidiary foods are also necessary. These foods can supplement energy for people. They mainly include biscuit, vegetables, fruits, red meat, nut and milk. Biscuit is mainly made of wheat. Therefore, it can provide energy for the body in the form of carbohydrates. The high content of energy contained in biscuit can support people to finish all the jobs before the next meal. The iron contained in red meat is the basic component of the red blood cells inside the human body, which can provide oxygen for all the internal organs. The lack of iron can cause anemia and weariness. The best sources of iron are liver, red meat and so on. After people do some exercises and jobs, they can eat some nuts to supplement the physical strength. Therefore, people can bring some nuts like almond with them. In addition, when people have dinner, they should drink at least a kind of dairy product, such as milk. Milk can provide abundant calcium for the human body. It is known to all that calcium is an important element for people to improve the development of bones. When people can not sleep well, they can also drink a cup of warm milk. The tryptophan contained in milk can help the human brain adjust the sleep.