Getting enough water also is important. Many experts recommend at least eight 8-ounce glasses of water daily—more if you exercise frequently or are exposed to extremes of heat and cold. The 2010 Dietary Guidelines for Americans emphasize drinking more water and other calorie-free beverages, along with fat-free or low-fat milk and 100 percent fruit juices, instead of calorie-packed regular sodas.
Much of the sugar we eat is added to other foods, such as regular soft drinks, fruit drinks, puddings, ice cream and baked goods, to name just a few. Soft drinks and other sugary beverages are the No. 1 offenders in American diets. A 12-ounce can of regular soda contains 8 teaspoons of sugar, exceeding the daily maximum amount recommended for women.
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).
Fats contain both saturated and unsaturated (monounsaturated and polyunsaturated) fatty acids. Saturated fat raises blood cholesterol more than unsaturated fat, which may even help lower harmful cholesterol. Reducing saturated fat (most comes from meat, dairy and bakery products) to less than seven percent of total daily calories may help you reduce your cholesterol level. Whenever possible, replace saturated fat with monounsaturated and polyunsaturated fats.
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.
The overall effect is a tighter, more toned physique, but body weight could stay the same or even increase. Therefore, the obsession with numbers on a scale is unfounded; one can greatly improve appearance, enhance fitness levels, and eliminate unwanted fat all while maintaining a constant weight. Focus instead on a combination of body fat measurements in trouble spots and the image in the mirror.
The guidelines also establish ranges (called acceptable macronutrient distribution ranges or AMDR) for fat, carbohydrates and protein, instead of exact percentages of calories or numbers of grams. The report maintains that since all three categories serve as sources of energy, they can, to some extent, substitute for one another in providing calories.
A year later, a second Harvard study added to the concern. The Physicians' Health Study of 20,885 men did not evaluate diet per se, but it did measure the blood levels of ALA in 120 men who developed prostate cancer and compared them with the levels in 120 men who remained free of the disease. Men with moderately high ALA blood levels were 3.4 times more likely to develop prostate cancer than men with the lowest levels; curiously, though, men with the very highest levels were only 2 times more likely to get the disease.