You need to maintain a healthy, balanced diet as you age to prevent a host of age-related conditions ranging from osteoporosis to cancer to cardiovascular disease. At the same time, your metabolism is slowing, so you need to reduce your calorie intake to avoid gaining weight. Although you're slowing down in your twilight years, your body still needs adequate nutrition to maintain good health.
Calories
You need to eat a variety of foods while you keep your calorie intake to a level consistent with your age and gender. According to the National Institute on Aging, women older than 50 who are not very active should consume about 1,600 calories a day to maintain your weight and metabolism. Eat 1,800 calories if you're moderately active and closer to 2,000 if you engage in an active lifestyle and exercise regularly. Sedentary men should eat about 2,000 calories a day, 2,200 to 2,400 if you're moderately active and no more than 2,400 to 2,800 if you are active most days.
Calcium
Calcium and vitamin D are tantamount to preserving your active lifestyle as you age. According to the Weight-control Information Network, you should consume at least three servings of calcium rich, vitamin D-fortified food or drink every day. Low-fat milk, cheese and yogurt are effective sources of calcium and vitamin D, vital to maintain healthy bones and prevent osteoporosis. Soy-based foods or those that are low in lactose, such as buttermilk, may suit your tastes and digestive system better. Talk to your doctor about supplements if you have trouble getting vitamin D and calcium from your diet.
Fiber
Fiber is an important part of a healthy diet for seniors to keep your digestive system regular and reduce your risks of developing chronic conditions such as Type 2 diabetes and heart disease. Eat at least six servings of high fiber foods such as the whole grains in cereal, bread and pasta. Fiber, minerals and vitamins in your diet should come from fresh fruits and vegetables. The U.S. Department of Agriculture recommends two to four servings of fruit and three to five servings of vegetables every day. Beans are another effective source of fiber that also provide you with lean protein. Substitute your two to three servings of protein and meat dishes occasionally with beans to maintain a high fiber diet.
Limitations
While you're lowering your calorie intake as you age, you also need to limit the empty fat calories that could cause you to gain weight, increase your blood pressure and increase the risk of becoming obese with all its related medical issues. Read food labels to limit your intake of saturated and trans fats, sodium, added sugar and cholesterol. At the same time, you need some fat in your diet to maintain cell regeneration. Limit consumption of healthy fats that come from nuts, olive oil and fish to about 20 to 25 percent of your total calorie intake every day.
