Nutrition is particularly important when you are pregnant. Weight gain during pregnancy is normal—and it's not just because of the growing fetus; your body is storing fat for lactation. The National Academy of Sciences/Institute of Medicine (NAS/IOM) has determined that a gain of 25 to 35 pounds is desirable. However, underweight women should gain about 28 to 40 pounds, and overweight women should gain at least 15 pounds. The IOM has not given a recommendation for an upper limit for obese women, but some experts cap it as low as 13 pounds. If you fit into this category, discuss how much weight you should gain with your health care professional. Remember that pregnancy isn't the time to diet. Caloric restriction during pregnancy has been associated with reduced birth weight, which can be dangerous to the baby.
Women's experience of health and disease differ from those of men, due to unique biological, social and behavioural conditions. Biological differences vary all the way from phenotype to the cellular, and manifest unique risks for the development of ill health. The World Health Organization (WHO) defines health as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity". Women's health is an example of population health, the health of a specific defined population.
In 2013 about 289,000 women (800 per day) in the world died due to pregnancy-related causes, with large differences between developed and developing countries. Maternal mortality in western nations had been steadily falling, and forms the subject of annual reports and reviews. Yet, between 1987 and 2011, maternal mortality in the United States rose from 7.2 to 17.8 deaths per 100,000 live births, this is reflected in the Maternal Mortality Ratio (MMR). By contrast rates as high as 1,000 per birth are reported in the rest of the world, with the highest rates in Sub-Saharan Africa and South Asia, which account for 86% of such deaths. These deaths are rarely investigated, yet the World Health Organization considers that 99% of these deaths, the majority of which occur within 24 hours of childbirth, are preventable if the appropriate infrastructure, training, and facilities were in place. In these resource-poor countries, maternal health is further eroded by poverty and adverse economic factors which impact the roads, health care facilities, equipment and supplies in addition to limited skilled personnel. Other problems include cultural attitudes towards sexuality, contraception, child marriage, home birth and the ability to recognise medical emergencies. The direct causes of these maternal deaths are hemorrhage, eclampsia, obstructed labor, sepsis and unskilled abortion. In addition malaria and AIDS complicate pregnancy. In the period 2003–2009 hemorrhage was the leading cause of death, accounting for 27% of deaths in developing countries and 16% in developed countries.
We only included studies that reported on women's health and nutrition outcomes, and excluded studies that were targeted to women but that reported only on health and nutrition outcomes of children (including birth outcomes). We included outcomes for adolescent girls ages 10–19 y, pregnant and lactating women, nonpregnant and nonlactating women of reproductive age (>19 y), and older women. Studies that described interventions targeting a wider age range of adolescent girls (e.g., ages 8–24 y) were also included but adolescent girls aged >19 y were reported in this review as nonpregnant and nonlactating women of reproductive age. Although many adolescents in low- and middle-income countries are married and bearing children, adolescents (10–19 y) as reported in this review reflect girls who are nonpregnant and nonlactating. The few interventions in low- and middle-income countries that target pregnant and lactating adolescents are reported under pregnant and lactating women. A description of the articles included in this review can be found in Supplemental Table 1.
Most experts recommend 1,300 mg of calcium a day for girls aged 9 through 19. Natural sources of calcium, such as low-fat dairy products, are the smartest choice, because they also contain vitamin D and protein, both required for calcium absorption. Milk, yogurt, and cheese contribute most of the calcium in our diets. Some vegetables are also good sources, including broccoli, kale, and Chinese cabbage. Many foods are supplemented with calcium, including some brands of orange juice and tofu. The daily intake for Vitamin D is 600 IU per day for most children and healthy adults.
Good sources of iron include liver, kidneys, red meat, poultry, eggs, peas, legumes, dried fruits and dark, green leafy vegetables. Three ounces of cooked chicken liver contains 7.2 mg of iron; a cup of cooked spinach contains 6.4 mg. Your health care professional will probably recommend iron supplements during pregnancy (probably starting at 30 mg per day).
Osteoporosis ranks sixth amongst chronic diseases of women in the United States, with an overall prevalence of 18%, and a much higher rate involving the femur, neck or lumbar spine amongst women (16%) than men (4%), over the age of 50 (Gronowski and Schindler, Table IV). Osteoporosis is a risk factor for bone fracture and about 20% of senior citizens who sustain a hip fracture die within a year.  The gender gap is largely the result of the reduction of estrogen levels in women following the menopause. Hormone Replacement Therapy (HRT) has been shown to reduce this risk by 25–30%, and was a common reason for prescribing it during the 1980s and 1990s. However the Women's Health Initiative (WHI) study that demonstrated that the risks of HRT outweighed the benefits has since led to a decline in HRT usage.
What you eat is even more important as you enter your 40s. Women need protein (meat, fish, dairy, beans, and nuts), carbohydrates (whole grains), fats (healthy oils), vitamins, minerals, and water. These foods have been linked to some disease prevention, such as osteoporosis, high blood pressure, heart disease, diabetes, and certain cancers. The American Academy of Family Physicians supports the development of healthy food supply chains in supplemental nutrition programs so as to broaden the availability of healthy food.
In addition to diet, exercise and other lifestyle factors can also play an important role in bone health. Smoking and drinking too much alcohol can increase your chances of developing osteoporosis, while weight-bearing exercise (such as walking, dancing, yoga, or lifting weights) can lower your risk. Strength or resistance training—using machines, free weights, elastic bands, or your own body weight—can be especially effective in helping to prevent loss of bone mass as you age.