If you lose weight suddenly or for unknown reasons, talk to your health care professional immediately. Unexplained weight loss may indicate a serious health condition. And even if it doesn't, simply being underweight is linked to menstrual irregularity, menstrual cessation (and sometimes, as a result, dental problems, such as erosion of the enamel and osteoporosis) and a higher risk of early death.
Both your nutritional needs (the food and water) and your metabolism (how fast your body converts food to energy) change at this age. Your metabolism gets slower. Women lose about half a pound of muscle per year starting around the age of 40. That makes losing weight even more difficult. Some of the changes women experience are due to decreased hormones, reduced activity level, and medical conditions.
All youth need calcium to build peak (maximum) bone mass during their early years of life. Low calcium intake is one important factor in the development of osteoporosis, a disease in which bone density decreases and leads to weak bones and future fractures. Women have a greater risk than men of developing osteoporosis. During adolescence and early adulthood, women should include good food sources of calcium in their diets This is when bone growth is occurring and calcium is being deposited into the bone. This occurs in women until they are 30 to 35 years of age. Women 25 to 50 years of age should have 1,000 mg of calcium each day, while women near or past menopause should have 1,200 mg of calcium daily if they are taking estrogen replacement therapy; otherwise, 1,500 mg per day is recommended. Women older than 65 years of age should have 1,500 mg per day.
In the past, women have often tried to make up deficits in their diet though the use of vitamins and supplements. However, while supplements can be a useful safeguard against occasional nutrient shortfalls, they can’t compensate for an unbalanced or unhealthy diet. To ensure you get all the nutrients you need from the food you eat, try to aim for a diet rich in fruit, vegetables, quality protein, healthy fats, and low in processed, fried, and sugary foods.