Based on the physiological changes in the various systems and organs of the elderly, their nutrition should focus on anti-aging and disease prevention, aiming to maintain physical and mental health and extend lifespan. Therefore, the requirements for various nutrients differ from those of young and middle-aged adults.
1. Energy: The energy requirements of the elderly decrease with age. For instance, while individuals aged 20-34 generally require 9623-10878 kilojoules per day, those aged 70-90 require 7531-8360 kilojoules. This is due to a reduced basal metabolic rate and decreased physical activity. Therefore, nutrition experts recommend that for the 50-90 age range, energy intake can be reduced by 10% compared to adults, by 20% for the 60-90 age range, and by 30% after age 70. However, a reduction in energy often leads to a decrease in total food intake, while the requirements for other nutrients do not necessarily decrease with age, which requires attention.
2. Protein: The protein requirements of the elderly are no lower than those of adults. Due to increased catabolism and gradually slowing anabolism, a negative nitrogen balance is more likely to occur. Therefore, the protein intake for the elderly should not be lower than that of adults, especially when calculated per kilogram of body weight. It is advisable to choose high-quality proteins for better utilization. Under normal circumstances, the proportion of protein in the total daily intake should also be increased, to around 12%-14%.
3. Carbohydrates: The elderly should consume a variety of carbohydrates, but the proportion of polysaccharides should not be too small. Fructose is less likely to be converted into fat in the body, so fruit jams and honey can be consumed as part of the sugar intake. Under normal conditions, a proportion of carbohydrates in the total caloric intake of around 60% is appropriate.
4. Lipids: The elderly, like adults, require lipids, which aid in the absorption of fat-soluble vitamins and enhance the flavor of vegetable-based foods. Lipids should be primarily from plant oils, but it is not necessary to eliminate all animal fats, as an excessive amount of unsaturated fatty acids in the diet is not necessarily beneficial.
5. Iron and Calcium: Elderly women may experience varying degrees of anemia for complex reasons, including a reduced stomach capacity, decreased absorption of iron due to lower gastric acid and intrinsic factor, impaired hematopoietic function, and insufficient intake of vitamin C and trace elements. However, under normal circumstances, the quality of iron is a primary concern; the absorption rate of iron from animal muscle and blood is higher than that from plant-based foods, which must be noted. Elderly women are prone to osteomalacia and reduced bone density, leading to osteoporosis, which is related not only to hormones and vitamin D but also to calcium supply. The calcium from dairy products has a higher absorption rate than that from plant-based foods. The total calcium intake should not be lower than the standard for adults, and elderly women should consume no less than 800 milligrams of calcium per day.
6. Salt: The elderly should consume less salt, with 5 grams per day being generally appropriate. Individuals with hypertension or coronary heart disease should limit their intake to less than 3 grams.
7. Vitamins: The vitamin requirements for the elderly are the same as for young people. Nutritional surveys of the elderly often reveal inadequate intake of vitamin A and B-complex vitamins. Vitamin C is also very important for the elderly, but vitamins A and D are not better in excess.
8. Dietary Fiber: Dietary fiber is relatively important for the elderly. It aids digestion and intestinal motility, prevents constipation, helps prevent colon cancer, and lowers blood cholesterol. Therefore, coarse grains should not be excluded from the diet of the elderly, and special attention should be paid to consuming fresh vegetables and fruits.
In summary, the nutritional needs of elderly women can be summarized as "Three Lows," "Three Adequates," and "Three Moderates": low fat, low salt; adequate vitamins, adequate dietary fiber, and adequate minerals (calcium, magnesium, iron, etc.); moderate energy, moderate high-quality protein, and moderate trace elements.