As people grow older, their food and nutritional needs change. The pattern and sequence of aging changes are always the same, but the rate at which these changes occur differs significantly from one person to the other. Environmental factors, such as exposure to toxic chemicals or level of nutrition, influence the rate of physiological aging. Let us examine the benefits of an appropriate diet and exercise pattern on the physical health and life span of men and women.

In brief, critical changes in vital organ systems occur, making nutrition a soft target in older people. For example, cognitive function or the ability to self- feed diminishes, leading to weight loss and poor nutritional status.

The cardiovascular and renal systems become less competent in delivering nutrients and removing waste products from the body. The gastrointestinal tract is unable to absorb nutrients as effectively. Thus, as organ systems under go constant change decreasing in their functional capacity with age, it would only be right to provide the body with food that is easy on the bio-system and not a burden.

Energy needs decrease with age, as the elderly are more sedentary. However, this does not mean that the body should be deprived of its share amount of vitamins and minerals required to maintain body function. The amount of energy required by elderly people is based on changes in the resting energy expenditure (REE) and physical activity. Sex, age, body size, thyroid status and body composition influence the REE, but the major influence is the amount of lean body mass. Women at all ages have lower REE per unit of body height and weight than men. Thus, it would be advisable for women to stick to 1,500 to 2000 Kcal and for men to stay within the 1,800 - 2,800 Kcal range.

Protein definitely
Protein is one nutrient that is most susceptible to being lost from the body with age (through low grade infections, inflammation, cells lost from skin, hair, and gastrointestinal tract). If not adequately replenished from the diet, the body will fall prey to negative nitrogen balance.

Negative nitrogen balance leads to slow healing, poor skin and mucosal integrity, not to forget, a weak immune system. Thus nutritionists highly recommend high protein sources like 1 cup milk, curds, pudding, milkshake, or 1 ½ cups of ice-cream, cheese, or paneer, tofu, dry beans. ½ a cup of tuna, chicken legs/ thigh, 2 fish sticks, 2 eggs, 1 cup baked beans, 4 tbsp of peanut butter. 2-3 servings a day of these foods should see you in a positive nitrogen balance.

Water
Water is supplied to the body through food, liquids, and water of oxidation. In younger people, the thirst mechanism ensures adequate fluid intake, but diminished sensitivity to dehydration and reduced sensation to thirst generally lowers spontaneous fluid intake in older people. Elderly need 6-8 cups of water or liquid a day. Sources of liquid, in addition to water are fruit and vegetable juices, milk, caffeine free coffee, teas and herbal teas.

Vitamins
Vitamins, especially the water soluble ones, should be seen to on a daily basis. Thiamin, riboflavin, niacin, pyridoxine, folate and vitamin C levels may get affected due to low dietary intake, excessive alcohol consumption or overuse of prescription drugs. A safe and effective way to ensure that these are replenished on a timely basis is to provide 2-4 servings of fruit and 3-5 servings of vegetables daily. For example, 1 orange, banana, ¾ cup of fruit juice, 5 prunes, ½ cup of fruit cocktail, ½ a cup of strawberries. Similarly, for vegetables ½ a cup of corn, carrots, beans or mashed potato. 1 cup of salad greens, ¾ cup of vegetable juice should suffice.    
The increase in the number of older people presents both a challenge and a responsibility.

The author is a member, Health Professions Council, UK and can be contacted at uggoblin@hotmail.com