Question: I am following an extremely strict weight-loss diet. Should I take vitamins to keep my energy level up when I'm not eating as much as usual?
Answer: No. Vitamins cannot give you extra energy. Energy - or, in everyday terms, calories - comes from carbohydrates, proteins, fats and alcohol. These are the energy nutrients. In order for our bodies to make use of the energy - "burn the calories" - we also need other nutrients: vitamins and minerals. Without them, we would develop symptoms of deficiency.One such symptom is fatigue. But taking vitamins to cure fatigue will only work if a vitamin deficiency is the reason behind the fatigue. Vitamins themselves don't provide you with pep and energy.
If you want to take a mul-ti-vitamin/mineral supplement containing no more than 100 percent of the Recommended Dietary Allowance for each nutrient it contains, that is perfectly acceptable. Beyond that, eat a diet rich in essential nutrients and devoid of empty calories, and exercise regularly.
If your diet is extremely strict because you wish to lose weight fast, you may feel tired due to insufficient calories. Taking vitamins won't counteract this. It's better to lose weight slowly and steadily.
Question: My 8-year-old daughter has suddenly developed a great sensitivity toward animals and has decided that she will no longer eat meat, poultry or fish. I respect her feelings but I worry about her health. Will she be able to grow properly on a vegetarian diet?
Answer: Provided she eats milk, cheese and eggs, she should do just fine. They contain all the essential amino acids needed to meet the demands of growth and to repair body tissues. An egg and either three cups of milk or yogurt or 3 ounces of hard cheese will just about cover her daily requirement for amino acids.
You can also bolster her diet with other sources of protein, such as dried beans, nuts, seeds and vegetables. The protein in these foods isn't as high-caliber as that in animal foods, but if they are eaten as part of a meal containing dairy products or eggs, the missing amino acids will be supplied, improving their quality and making them more useful to the body.
It's also a good idea to include a vitamin C source at meals, since it improves iron absorption. Citrus fruits, strawberries, broccoli, tomatoes, peppers and kale, for example, will enhance iron absorption from legumes, nuts, seeds or whole-grain or enriched breads and cereals.
Perhaps in the future your daughter may change her mind and resume eating meat, fish and poultry. Meanwhile, it sounds as if you are taking a sensible tack in respecting her feelings. With a little extra effort, it certainly is possibleto ensure that she eats a nutritious diet that promotes health and development.
Question: With all of the focus on vitamins that seem to help protect against bowel cancer, fiber seems to have assumed a back seat. Is this because scientific opinion has changed, or is fiber still considered quite important?
Answer: The bulk of the evidence continues to suggest that fiber is important in protecting against bowel cancer. The incidence of cancer is higher in populations where fiber intake is low than in societies where people typically consume large amounts. Similarly, when researchers compare the diets of individuals who have the disease with those who do not, fiber exerts a protective role.
Some evidence suggests that increased intake of fruit and vegetable fiber may be more protective against rectal cancer, while increased grain fiber may protect against cancer further up the bowel. And while the findings are not completely consistent, one recent study following people over time and tracking new cases found that increased intake of vegetables and high-fiber grains reduced the risk of fatal colon cancer.
Animal studies also generally support the hypothesis that fiber, - wheat fiber, in particular - exerts a protective effect against bowel cancer. This effect may, in part, be related to the gases and fatty acids which are produced as bacteria in the gut ferment it.
In short, our understanding of the potential protective role for fiber is quite incomplete. What we do know is that different types of fiber have different effects and that it is unwise to focus on consuming large amounts of one type over others. The "last word" on fiber may be decades away. But there is enough evidence to support increasing your fiber intake to between 20 grams and 35 grams a day by eating generous amounts of a variety of grains, legumes, vegetables and fruits.
Washington Post Writers Group