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Iron
For women, the RDA for iron is 15 milligrams per
day, 5 milligrams more than the RDA for men. Women need
more of this mineral because they lose an average of 15
to 20 milligrams of iron each month during menstruation.
Without enough iron, iron deficiency anemia can develop
and cause symptoms that include pallor, fatigue and headaches.
After menopause, body iron
stores generally begin to increase. Therefore, iron deficiency
in women over 50 may indicate blood loss from another source,
and should be checked by a physician.
Animal products--meat, fish
and poultry--are good and important sources of iron. In
addition, the type of iron, known as heme iron, in these
foods is well absorbed in the human intestine.
Dietary iron from plant sources,
called non-heme, are found in peas and beans, spinach and
other green leafy vegetables, potatoes, and whole-grain
and iron-fortified cereal products. Although non-heme iron
is not as well absorbed as heme iron, the amount of non-heme
iron absorbed from a meal is influenced by other constituents
in the diet. The addition of even relatively small amounts
of meat or foods containing vitamin C substantially increases
the total amount of iron absorbed from the entire meal.
Calories and Weight
Control
The Food and Nutrition Board of the National Research Council
recommends that the average woman between 23 and 50 eat
about 2,200 calories a day to maintain weight. (Chart of
Suggested Weights for Adults)
The best way for a woman
to determine whether she's eating the right number of calories
is to "keep stepping on the scale," says FDA's
Stephenson.
She cautions, however, that
cutting back on calories isn't always the answer to losing
weight. "You don't really want to cut back any more
[calories] if you're down around that [1,500 calories] range,"
says Stephenson. She explains that the fewer the calories
you have to work with, the harder it is to meet all your
daily requirements for a healthy diet.
"If you find you are
gaining weight, you need to think of not only cutting calories,
but also about increasing exercise," she says. "Calories
are only half the equation for weight control. Physical
activity burns calories, increases the proportion of lean
to fat body mass, and raises your metabolism. So, a combination
of both calorie control and increased physical activity
is important for attaining healthy weight.
"On the other hand,
if you've been pigging out--well, you know what you have
to do."
Cholesterol
Women tend to have higher levels than men of a desirable
type of cholesterol called HDLs (high-density lipoproteins)
until menopause, leading some researchers to believe there
is a link between HDLs and estrogen levels. But this doesn't
let women off the hook--a diet high in saturated fat and
cholesterol can still mean trouble.
For both women and men, blood
cholesterol levels of below 200 milligrams are desirable.
Levels between 200 and 239 milligrams are considered borderline,
and anything over 240 milligrams is high. High levels of
blood cholesterol increase the risk of coronary heart disease.
To keep levels in the good
range, the National Cholesterol Education Program of the
National Heart, Lung, and Blood Institute recommends eating
no more than 300 milligrams of cholesterol a day. Cholesterol
is found only in food from animal sources, such as egg yolks,
dairy products, meat, poultry, shellfish, and--in smaller
amounts--fish and some processed products containing animal
foods.
Even more important than
limiting cholesterol to under 300 milligrams is keeping
saturated fat to under 10 percent of total calories, says
Nancy Ernst, the nutrition coordinator for the National
Heart, Lung, and Blood Institute.
"Don't even think about
cholesterol in your diet," says Ernst. "Focus
on reducing saturated fat."
Fat
In the United States, out of every 100,000 women, approximately
27 die from breast cancer each year. In Japan, breast cancer
deaths are fewer than 7 per 100,000. Some scientists think
that the difference in death rates may be related to the
different amounts of fat in the average diet in each country--40
percent for American women versus 20 percent in Japan.
"We believe pretty strongly
in the link [between high-fat diets and breast cancer],"
says Jeffrey McKenna, director of NCI's Cancer Awareness
Program.
Population studies have also
linked high-fat diets to other cancers, particularly colorectal
cancer.
Fat does, however, serve
a purpose in the diet. Fats in foods provide energy and
help the body absorb certain vitamins. But it is as easy
as pie (and doughnuts, ice cream, and sirloin steaks) to
eat too much.
For a healthy diet, the diet
and health report of the National Research Council recommends
reducing fat to no more than 30 percent of total calories.
(Figure out your fat intake.) But that's not all. In terms
of heart disease, the kinds of fat you eat are as important
as how much.
There are three kinds of
fat--saturated, polyunsaturated and monounsaturated. All
three are equal when it comes to calories--9 per gram (compared
to 4 calories per gram for protein or carbohydrate). But
they aren't equal when it comes to how they affect your
health.
More than anything else in
the diet, saturated fat can raise your blood cholesterol
level. Because of this risk, less than one-third of your
daily fat intake (less than 10 percent of total calories)
should come from saturated fats.
That's the bad news. The
good news is polyunsaturated and monounsaturated may actually
lower blood cholesterol levels. The diet and health report
recommends that not more than 10 percent of total calories
should be from polyunsaturated fat, and monounsaturated
fat should make up the remaining 10 percent.
The foods with the highest
amounts of saturated fat come from animals--meat, of course,
and foods derived from animals, such as butter, cream, ice
cream, and cheese. In addition to animal products, coconut
and palm kernel oils are very high in saturated fat--over
90 percent.
The best sources for polyunsaturated
fats are plant-based oils--sunflower, corn, soybean, cottonseed,
and safflower. Monounsaturated fats are found in the largest
amounts in olive, canola and peanut oils.
Fiber
An apple a day--that is, a whole apple with the skin--will
give you approximately 3.6 grams of fiber. That's a good
start, but you still need a lot more fruits, vegetables,
and whole grains to meet the daily level of 20 to 30 grams
of fiber recommended by the National Cancer Institute.
Eating foods with plenty
of complex carbohydrates and fiber (vegetables, fruits,
and grain products) is part of a healthy diet for several
reasons. A fiber-rich diet is helpful in the management
of constipation and may be related to lower rates of colon
cancer. These types of foods are generally low in fat and
can be substitutes for fatty foods.
Fiber comes in two forms--insoluble
and soluble. Insoluble fiber, mostly found in whole-grain
products, vegetables and fruit, provides bulk for stool
formation and helps move wastes more quickly through the
colon. Another benefit is the full feeling fiber may create
in the stomach, a possible deterrent to overeating.
Soluble fiber has been linked
to lowering blood cholesterol levels, but that's still a
research area according to the Surgeon General's Report
on Nutrition and Health. There are many sources of soluble
fiber, including peas and beans, many vegetables and fruits,
and rice, corn and oat bran. There are even small amounts
in pasta, crackers, and other bakery products.
Although foods containing
fiber seem to exert a protective effect against some cancers,
the diet and health report points out there is no conclusive
evidence that dietary fiber itself, rather than other components,
exerts this effect. Therefore, the report does not recommend
the use of fiber supplements.
As important as fiber is
to good health, it can be overdone. NCI recommends an upper
limit of 35 grams a day. More probably won't further increase
the benefits from fiber, and may interfere with the body's
ability to absorb iron and other minerals.
When increasing the amount
of fiber in your diet, do it slowly, so your body can become
accustomed to handling it. Adding too much fiber too quickly
may lead to uncomfortable side effects, including abdominal
discomfort, flatulence and diarrhea.
Food Preparation
Carefully selecting foods for a well-balanced diet can end
up a wasted effort if equal care isn't used in the kitchen.
Some important points to help make the most of healthy food:
To help reduce fat, broil, bake or microwave food rather
than frying or deep-fat frying. Cook vegetables in as little
water as possible, or, instead of boiling food, try steaming.
The steamer basket keeps the food above the water so the
nutrients can't be washed away. Also, heat can destroy some
nutrients, so don't overcook. Use fresh foods as soon as
possible to avoid loss of vitamins. Season vegetables with
herbs and spices instead of high-fat sauces, butter or margarine.
Try lemon juice as a salad dressing. Substitute plain low-fat
yogurt, blender-whipped low-fat cottage cheese, or buttermilk
in recipes that call for sour cream or mayonnaise. Use skim
or low-fat milk in place of whole milk in puddings, soups,
and baked products. |
