A person's caloric requirement depends on his body size and exercise level. Sedentary people of both genders will keep their weight stable by taking in about 13 calories per pound of body weight each day. Moderate physical activity boosts this requirement to 16 calories a pound, and vigorous exercise calls for about 18 calories a pound. On average, a moderately active 125-pound woman needs 2,000 calories a day; a 175-pound guy with a similar exercise pattern needs 2,800 calories. And like women, men will lose weight only if they burn more calories than they take in.
Although growing bodies need plenty of energy in the form of calories, many children and teenagers consume way too many, says Ruth Frechman, RD, a spokesperson for the American Dietetic Association. The latest findings from federal surveys show that 18% of adolescents and teenagers are fatter than they should be. Kids who are obese are 16 times more likely than healthy weight children to become obese as adults, other findings show.
The trick to biking uphill is to look ahead and anticipate. “Try to plan for what's coming,” says Georgia Gould, a LUNA pro athlete and 2012 Olympic bronze medalist in women's mountain biking. “Start shifting down one gear at a time for a smooth, energy-saving transition. Ideally your cadence should stay the same as you transition from harder to easier gears.”
Iron: Essential for healthy blood cells, iron becomes especially important when girls begin to menstruate. With each period, a woman loses small amounts of iron. “About 10% of American women are iron deficient,” says Dorothy Klimis-Zacas, PhD, a professor of nutrition at the University of Maine and co-editor of Nutritional Concerns of Women (CRC Press, 2003). “About 5% have iron deficiency anemia.” Symptoms of low iron include fatigue, impaired immunity, and poor performance at school or work.
Dairy. Women should get 3 cups of dairy each day, but most women get only half that amount.6 If you can’t drink milk, try to eat low-fat plain yogurt or low-fat cheese. Dairy products are among the best food sources of the mineral calcium, but some vegetables such as kale and broccoli also have calcium, as do some fortified foods such as fortified soymilk, fortified cereals, and many fruit juices. Most girls ages 9 to 18 and women older than 50 need more calcium for good bone health.