1. Changes in Body Composition
The composition of the human body undergoes slow changes with aging. The main components of the body are water, inorganic salts, proteins, and fats. The first three are lean tissues, which decrease with age, while fat increases with age. The distribution of fat within the body also changes, with more fat being deposited around the abdomen and visceral organs.
2. Changes in Organ System Function
Changes in the digestive system include loose and missing teeth, which affect chewing; a decrease in taste buds, resulting in diminished taste perception for sweet and salty flavors; decreased stomach acid secretion and lower activity of digestive enzymes, which affect the hydrolysis and digestion of food, leading to decreased absorption of various nutrients; slowed intestinal motility, making constipation more common, and increasing the time harmful substances stay in the intestines, leading to toxin accumulation or allergies.
3. Changes in Metabolic Function
Basal metabolic rate decreases, synthesis metabolism decreases, and breakdown metabolism increases. Basal metabolism refers to the energy required for basic life activities in a resting state, in an appropriate temperature environment. The rate of basal metabolism per unit time is called basal metabolic rate. With a decrease in basal metabolic rate and a decrease in physical activity in the elderly, energy expenditure decreases.
In addition, due to disturbances in fat metabolism, high blood lipid levels are more likely to occur, leading to atherosclerosis in various organ systems, resulting in inadequate blood supply and decreased function of important organs such as the heart, brain, liver, and kidneys.
Nutrition is closely related to longevity
With aging and nutritional imbalances, older adults become more sensitive to internal and external stimuli, injuries, and various diseases. The immune regulatory function and adaptability to environmental changes in the body decline, leading to a decrease in immune defense, self-stability, and immune surveillance. This makes older adults more susceptible to infectious and non-infectious diseases.
Food is better than medicine
Many elderly people have the misconception that they should eat certain foods to supplement specific nutrients, such as calcium for calcium deficiency or vitamins for vitamin deficiency. While it is important to supplement vitamins when food intake is insufficient or in special cases, it should be done under the guidance of a doctor. Excessive intake can cause side effects and even harm. Due to the decreased metabolism and immune function in the elderly, it is necessary to ensure an adequate intake of various vitamins. Since most vitamins cannot be synthesized in the body and the elderly often have decreased food intake, it is important to consume foods rich in vitamins. For example, vitamin A can be obtained from animal foods and yellow-green vegetables rich in carotenoids. Vitamin D can be synthesized in the skin through exposure to sunlight and can also be obtained from animal foods such as fish, liver, and egg yolks. Foods rich in vitamin B1 include meat, beans, and coarse grains. Vitamin B2 is mainly found in animal foods such as meat, poultry, fish, and green leafy vegetables. Vitamin C is mainly obtained from fresh vegetables and fruits.
The recommended daily intake of folate for the elderly is the same as that for adults, which is 400 micrograms. Folate is widely found in various animal and plant foods, not just leafy greens. It is also found in animal liver, beans, fruits, and nuts.
Eating well does not necessarily prevent anemia in older adults, as one of the reasons may be poor absorption and utilization of iron. When choosing foods, it is important to select those with high heme iron content, such as pork liver, poultry, and fish, and also consume vegetables and fruits high in vitamin C to enhance iron absorption.
Dietary Recommendations for Older Adults
A well-balanced diet for older adults should include approximately 300 grams of grains per day, 50 grams of meat and poultry, 50 grams of fish and shellfish, 25 grams of eggs, 50 grams of beans and soy products, 500 grams of vegetables, 250 grams of fruits, 250 grams of dairy products, and 25 grams of cooking oil.
Meals should be consumed at regular times and in appropriate portions, aiming to feel 70% full. It is important to prioritize high-quality foods that are fresh and diverse, and to maintain a balanced diet.
