1, low basal metabolic rate;?

2, cardiovascular system function decline;

3, digestive system function decline;

4, body composition changes;

5, metabolic function is reduced;

6, oxidative damage in the body aggravated by the elderly, myocardial and brain tissue in the rate of deposition of lipofuscin is significantly higher than that of young people;

7, immune function decline.

Second, nutritional needs?

1, energy: the need for energy in the elderly is reduced, so the dietary energy intake to maintain energy balance, to achieve and maintain ideal body weight is appropriate.

2, protein: the elderly are prone to negative nitrogen balance, and because the elderly liver and kidney function is reduced, excessive protein intake can increase the burden on the liver and kidneys. Therefore, dietary protein intake should be appropriate for a moderate amount of high-quality protein, protein energy accounted for 12% -14% of the total.

3, lipids: due to the elderly bile secretion and esterase activity decreases and the decline in fat digestion, so the fat intake should not be too much fat energy accounted for 20% of the total dietary energy - 30% is appropriate. Some foods containing high cholesterol such as animal brain, fish eggs, crab, egg yolk, liver, kidney and other foods should not be eaten.

4, carbohydrates, the elderly glucose tolerance is low, the role of blood glucose regulation is weakened, easy to occur blood sugar increase. Too much sugar in the body can also be converted to fat, causing obesity, hyperlipidemia and other diseases. It should be appropriate to reduce the intake of monosaccharide, disaccharide and sweets, and increase the intake of dietary fiber appropriately.

5, minerals Daily dietary supply of calcium, iron, selenium, zinc, copper, chromium, etc., to meet the needs of the body.

6, vitamins The utilization rate of vitamins in the elderly declined; outdoor activities to reduce the function of the skin to synthesize vitamin D decline, coupled with the decline in liver and kidney function leads to a decrease in the generation of active vitamin D, easy to vitamin A, vitamin D, folic acid and vitamin B and other deficiencies.

Three reasonable dietary principles

"Chinese residents in the Dietary Guidelines" on the dietary guidelines for the elderly in particular emphasized the following points:

1, a small amount of more than one meal drink, to prevent nutritional deficiencies.

2, active drinking water, active outdoor activities.

3, delay muscle decay, maintain appropriate weight.

4. Adequate food intake and encourage eating with company.