When a person enters old age, physiological functions begin to decline, such as metabolism slows down, gland secretion decreases, chewing, digestion, absorption and other abilities to reduce the muscle activity ability to weaken the body's resistance to decline, which easily lead to cardiovascular disease, metabolism and endocrine disorders, bones and joints, constipation and muscular atrophy, and so on, some of the diseases of old age occur. Changes in the physiological functions of the elderly have led to changes in the nutritional and dietary requirements of the elderly. Adequate nutrients must be consumed to maintain the normal functioning of the organism. \x0d\\ Nutritional Requirements in Old Age \x0d\\ As age increases, the various functions of the human body undergo varying degrees of degeneration. \x0d\\ Due to the physiological changes that characterize the elderly, the demand for nutrients is very different from that of adulthood, so it is necessary to supply a variety of nutrients that are consistent with the physiological condition of the elderly. According to the physical characteristics of the elderly, the principles that should be followed in diet are: reduce the supply of calories, eat less sugar and salt, eat more high protein foods, eat more vegetables and fruits, and pay attention to calcium supplementation. \x0d\calorie\\x0d\\usually the basal metabolic rate of the elderly is 10% to 15% lower than that of young adults, coupled with the reduction of physical activity in the elderly, so the energy consumption is also less, and thus the supply of calories should be appropriately lowered. total calorie supply for those over 65 years of age should be controlled at 1,900 to 2,400 kcal. Therefore, the elderly to maintain a healthy and sturdy body, do not consume too much caloric energy, so as not to be converted into fat stored in the body, too obese people prone to atherosclerosis and diabetes and other diseases, which will affect the life expectancy of people. \x0d\\protein\x0d\the elderly to maintain vitality, delay aging, the supply of protein must be sufficient, especially should pay attention to the amount of food and digestion and absorption rate. Good protein nutritional status can also enhance the ability of the elderly to resist disease. Elderly people should eat more animal food, such as meat, eggs, milk and soy products, its protein is rich in amino acids, and the number of adequate, appropriate ratio, easy to digest, suitable for the elderly to eat. According to our country's dietary situation, the demand for protein in the elderly is generally 1 gram per kilogram of body weight, accounting for 12% to 14% of the total calories in the diet, if consumed in excess, it will increase the burden on the kidneys. \x0d\carbohydrates\\x0d\\\x0d\carbohydrates are the main source of calories, and starch and sugar in rice, flour, and mixed grains are common carbohydrates. The diet of the elderly should not contain too much sucrose, because it will contribute to the increase in blood lipid content, the elderly health is not favorable, and sucrose in addition to the supply of calories, almost no other nutrients, if you eat too much, but also affect the balance of other nutrients. Fructose is most suitable for the elderly, therefore, the elderly should have an appropriate intake of various fruits and honey that contain more fructose. \x0d\fat\x0d\ for the elderly, intake of fat too much or too little are not beneficial, more is not easy to digest, on the cardiovascular, liver is not favorable; less affect the absorption of fat-soluble vitamins and dietary distribution. The daily fat intake of the elderly should be limited to 20% to 25% of the total energy. Should try to give less cholesterol-containing and more unsaturated fatty acid-containing foods, more vegetable oils and less saturated fatty acids in lean meat, fish, poultry and so on. Minimize the consumption of foods high in cholesterol such as egg yolks, animal brains, liver and fish. \x0d\hydration\x0d\ elderly people should be given the right amount of water, generally drinking water is controlled at about 2,000 milliliters per day is good. In order to give the elderly supplemental water, can be appropriate to increase the soup and other foods, these foods can help digestion, but also to replenish water. For the elderly who have the habit of drinking a lot of water, the amount of water consumed should be appropriately reduced so as not to drink too much water and increase the burden on the heart and kidneys. \x0d\ trace elements\x0d\\ more supplemental calcium, phosphorus, iron, iodine and other trace elements. Milk, shrimp, kelp rich in calcium; fish, meat, eggs, milk, beans in high phosphorus content; animal liver, egg yolks, fish and aquatic products in iron content, can be selected according to the situation; kelp, seaweed, nori in the potassium, sulfur, iron content is more beneficial to the prevention and treatment of hypertension, atherosclerosis. Regular use of tamarind, kelp, mushrooms, peanuts, walnuts, sesame, etc. can increase the intake of essential trace elements such as zinc, selenium, copper, etc., to help prevent and control hypertension and atherosclerosis. \x0d\vitamins\x0d\\the elderly should eat more vitamin-rich foods, which play an important role in maintaining the health of the elderly, strengthening resistance, promoting appetite and slowing down the aging process. Eat more fresh colored leafy vegetables or fruits, every day can food part of coarse grains; in addition, fish, beans and lean meat can supply high-quality protein and vitamin b2 and so on. However, according to our people's dietary structure and characteristics, some vitamin intake is more difficult to meet the standard, such as vitamin a, vitamin b2, etc., can be considered in addition to the diet, supplemented with a certain amount of vitamin preparations. However, it should be noted that the supplementation of vitamins, fat-soluble vitamins, such as vitamin A, vitamin D, vitamin E, the dosage can not be too large, so as not to cause adverse reactions.