It's no surprise that women have different nutrition needs than men. Hormonal changes that occur with menstruation, pregnancy, breastfeeding and menopause alter a woman's daily need for nutrients such as calcium, iron and folate.
The fact that women are at unique risk for osteoporosis, breast cancer and weight-related problems also influences what foods a woman should eat for optimum health.
Tailoring food intake to keep up with a woman's changing body can prevent vitamin deficiencies and unwanted weight gain, and help guard against chronic diseases.
While the basics of healthy eating are essentially the same for women and men, unique nutritional needs arise for women as they age. The following strategies will help women eat healthfully and meet nutrient needs across the decades.
In your twenties
If you're in your twenties, the focus should be on building a strong nutritional foundation for the future. And that starts with calcium, folate and iron.
Women continue to build bone density in their twenties. By the age of 30, peak bone mass - the maximum amount of bone you will have - is achieved. Meeting daily calcium requirements (1,000 milligrams) helps strengthen bones and reduce the risk of osteoporosis.
Research suggests that a high-calcium diet might even ease symptoms of PMS (premenstrual syndrome) including mood swings, fluid retention, food cravings and cramps.
To meet calcium needs, consume three daily servings of milk or milk alternatives. (One serving equals 250 millilitres of milk or soy beverage, 175 ml yogurt, or 45 grams cheese.) If your diet lacks calcium, reach for a supplement.
At this stage it's also important to ensure you're getting the recommended amount of folate (a B vitamin), especially if planning a pregnancy. Consuming 400 micrograms of folate each day from leafy greens, lentils, asparagus, fortified grains and a multivitamin helps prevent neural tube defects, birth defects that affect the brain and spinal cord.
Menstruating women need 18 milligrams of iron per day to help sustain energy, concentration and mood. (Vegetarians need an extra 14 milligrams to account for reduced iron absorption from plant foods.)
Good sources of iron include red meat, enriched breakfast cereals, whole grain breads, dried fruit, legumes, tofu and nuts.
A daily multivitamin with minerals will also help women meet daily iron needs.
In your thirties
A woman's metabolism starts to slow in her thirties because of age-related muscle loss. To keep your weight steady, you need to eat less and exercise more.
For every year after 30, women require seven fewer calories per day. In other words, by the age of 40 you should be eating 70 fewer calories each day than you did at 30.
Trim unnecessary calories from sweets, sugary drinks and refined starchy foods while still emphasizing foods rich in folate, calcium and iron.
Magnesium requirements increase in your early thirties. Women need 320 mg daily to help maintain strong bones and healthy blood pressure, and guard against heart disease.
Magnesium-rich foods include whole grains, wheat bran, nuts, seeds, legumes, dried fruit, spinach and green peas.
In your forties
During this decade, women begin the transition into perimenopause, the five- to 10-year period before the onset of menopause.
While vitamin and mineral requirements remain unchanged, women in their forties should concentrate on choosing nutritious foods to minimize perimenopausal symptoms such as hot flashes and insomnia and maintain good health.
Fine-tune your diet to reduce saturated (animal) fat, refined sugars and sodium. Consume no more than seven alcoholic beverages a week. Limit caffeine to 450 mg a day or less if you suffer sleep disturbances. (A 240-ml cup of coffee contains 100 to 150 mg of caffeine.) Incorporate more whole grains, oily fish, legumes, fruits and vegetables.
Adding foods rich in phyto (plant) estrogens such as tofu, soy beverages and soy nuts may help some women ease hot flashes.
Fifties and beyond
Most women reach menopause around age 50 and then enter post-menopause, the phase of life when osteoporosis, heart disease and breast cancer risks increase. (Menopause is deemed to have occurred when 12 months have passed since your last period.)
At the age of 50, calcium requirements increase to 1,500 mg daily. In most cases, women need to rely on calcium supplements to ensure they meet daily needs.
With age, women (and men) have a reduced capacity to produce vitamin D in the skin through sun exposure. For this reason, Health Canada advises adults older than 50 to take a daily vitamin D supplement of 400 IU (international units) to reduce the risk of osteoporosis and bone fracture. To guard against cancer, the Canadian Cancer Society recommends taking 1,000 IU of vitamin D all year round if you're older than 50.
Aging also affects the status of vitamin B{-1}{-2}, a nutrient needed for healthy nerve and blood cells and the production of DNA. To meet the recommended intake of 2.4 micrograms, adults over 50 are encouraged to take a multivitamin supplement, or consume fortified foods such as soy beverages.
While you can't prevent aging, eating right and staying active can help women feel energetic, prevent weight gain and maintain good health throughout your lifetime.
Leslie Beck is a Toronto-based dietitian at the Medcan Clinic. Her Food for Thought column appears every Wednesday in the Life section, on the Health page. She also appears on CTV's Canada AM every Wednesday. Her website is lesliebeck.com.
