”It is difficult to buy a thousand dollars to be thin in old age”. However, if you lose weight too quickly, do not be careless, should be early to the hospital for examination. There are degrees of thinness in the elderly. The normal thinning should be measured by the body mass index BMI = weight (kg) / height (m) squared, BMI value as long as the fluctuations in the range of 20 to 24, is basically a normal change. There is also an easier way to determine this: elderly people should be checked for illness if they lose 2.5 to 5 kg in a month. In addition, attention to some details of life can also detect changes in the body, such as the formerly fitted clothes become loose, the belt is loose or feel the shoes fat, should not be careless. The disease that can cause the elderly to lose weight is more common is diabetes, because the typical characteristics of diabetes on the body wasting this one, that is, “three more and one less”. If an elderly person suddenly becomes thin, they should go to the hospital for an early checkup to prevent missing the best time for treatment. If you are really suffering from diabetes, it is recommended to go to a regular hospital endocrinology department for treatment, rather than blindly listening to advertising. Of course, there are also some thinning is not caused by disease, but also can not be ignored. This is because weight loss affects the immune function of the body, leading to a decrease in resistance and therefore an increase in the chances of acute and chronic diseases. Lighter people lack fat protection in case of a fall and are more likely to break bones; people who are too thin lack the ability to withstand the cold and cannot withstand disease consumption. The elderly should take health as a priority and should not blindly restrict their diet to vegetarians, but ensure nutritional supply.