Most Americans get far more protein than they really need. In theory, that may not be wise. Like carbohydrates, protein provides 4 calories per gram, and excess calories from any source will be stored as body fat. Excess dietary protein increases calcium loss in the urine, perhaps raising the risk for osteoporosis ("thin bones," more a worry for women) and kidney stones (a particular worry for men).
A 55-year-old woman who gets less than 30 minutes of daily physical activity should eat five ounces of grains; two cups of vegetables; one and a half cups of fruit; three cups of milk; five ounces of meat and beans; five teaspoons of oils, and no more than 130 calories of additional fat and sugar. If she got 30 to 60 minutes of daily exercise, she could increase her intake to six ounces of grains; two and a half cups of vegetables; and up to 265 additional calories of fat and sugar.
A BMI of 25 to 29.9 is considered overweight and one 30 or above is considered obese. For an idea of what this means, a 5-foot 5-inch woman who weighs 150 pounds is overweight with a BMI of 25. At 180 pounds, she would be considered obese, with a BMI of 30. Keep in mind that the tables aren't always accurate, especially if you have a high muscle mass; are pregnant, nursing, frail or elderly; or if you are a teenager (i.e., still growing).
Here, too, body size is the main difference between the needs of males and females. Despite all the hype about high-protein diets, our protein requirements are really quite modest — only about a third of a gram per pound of body weight. For a 125-pound woman, that amounts to about 42 grams, for a 175-pound man, 58 grams. That's a tiny difference, just about half an ounce a day.
Sugar is a source of calories, not nutrients. Consuming too much sugar can lead to weight gain and tooth decay. Contrary to what many people think, there is no evidence linking high-sugar diets to hyperactivity or diabetes. However, high-fructose corn syrup, found in most processed foods, is linked with obesity, and obesity increases your risk for developing diabetes and other conditions.
Even if you are the most independent exerciser around, give a group fitness class a shot at least once a week—you may find that you enjoy it more than sweating solo. “Happiness and health are shared through social connectedness and closeness,” says Greg Chertok, director of sport psychology at the Physical Medicine and Rehabilitation Center in New Jersey. “Geography and proximity are predictors of how contagious emotions can be, and this may translate into an athletic environment too.” Sign up for Bikram, CrossFit, spin, or Zumba, and you could find yourself—gasp!—smiling at the gym thanks to your classmates.
Iron: Iron, too, remains a critical nutrient. Adult women between the ages of 19 and 50 need 18 mg a day. Pregnant women should shoot for 27 mg a day. “The volume of blood almost doubles when women are pregnant, which dramatically increases the demand for iron,” Schwartz tells WebMD. After delivery, lactating women need far less iron, only about 9 mg, because they are no longer menstruating. But as soon as women stop breast-feeding, they should return to 18 mg a day.
Among other things, you need calcium to build healthy bones and teeth, keep them strong as you age, regulate the heart’s rhythm, and ensure your nervous system functions properly. Calcium deficiency can lead to, or exacerbate, mood problems such as irritability, anxiety, depression, and sleep difficulties. If you don’t get enough calcium in your diet, your body will take calcium from your bones to ensure normal cell function, which can lead to weakened bones or osteoporosis. Women are at a greater risk than men of developing osteoporosis, so it’s important to get plenty of calcium, in combination with magnesium and vitamin D, to support your bone health.
If you thought texting changed your love life, imagine what it could do for your waistline. When people received motivational text messages promoting exercise and healthy behaviors twice a week (i.e., “Keep in the fridge a Ziploc with washed and precut vegetables 4 quick snack. Add 1 string cheese 4 proteins”), they lost an average of about 3 percent of their body weight in 12 weeks. Participants in the Virginia Commonwealth University study also showed an improvement in eating behaviors, exercise, and nutrition self-efficacy, and reported that the texts helped them adopt these new habits. Find health-minded friends and message each other reminders, or program your phone to send yourself healthy eating tips.