Losing weight requires tipping the energy balance scale by eating less, exercising more or some combination of the two. A pound of adipose tissue provides about 3500 Calories. Therefore, to lose a pound of fat, you need to reduce intake and increase expenditure by this amount. To lose a pound in a week, energy balance is required to maintain about 500 Calories/day.
The medical goal for weight loss in an overweight person is to reduce the health risks associated with being overweight. For most people, a loss of 5% to 15% of body weight will significantly reduce the chances of diseases. Losing weight slowly, at a rate of 1/2 to 2 lbs/week, helps ensure that most of what is lost is fat and not lean tissue. The more severe energy restriction needed for rapid weight loss leads to greater losses of water and protein and causes a more significant drop in BMR. People who lose weight rapidly are more likely to regain the weight, leading to repeated cycles of weight loss and gain. Successful long-term weight management involves a combination of decreasing intake, increasing activity, and changing the behavior patterns that led to weight gain in the first place.
Decreasing energy intake
For healthy weight loss, intake must be low in energy but high in nutrients in order to provide for all the body’s nutrient needs. Even when choosing nutrient-dense foods, it is difficult to meet nutrient needs with an intake of fewer than 1200 Calories/day; therefore, dieters consuming less than this amount should take a multivitamin/ multi-mineral supplement. Medical supervision is recommended if intake is below 800 Calories/day.
Increasing physical activity
Exercise increases energy expenditure and therefore makes weight loss easier. If food intake stays the same, adding enough exercise to expend 200 Calories five days a week will result in the loss of a pound in about three and a half weeks. Exercise also promotes muscle development, and because muscle is metabolically active tissue, increased muscle mass increases energy expenditure. In addition, physical activity improves overall fitness and relieves boredom and stress. Weight loss is maintained better when physical activity is included.
The Dietary Guidelines for Americans recommend an hour of moderate to vigorous activity on most days to prevent gradual weight gain in adulthood. For those who need to lose weight or have lost weight and want to keep it off, more than 60 minutes of moderate exercise per day may be necessary.
After people lose weight, they typically go off their “diet.” When eating patterns return to what they were previously, these dieters then regain the weight they lost. To manage your weight at a healthy level, you need to establish a pattern of food intake and exercise that allows you to enjoy foods and activities you like and that you can maintain throughout your life without gaining weight. Changing food consumption and exercise patterns requires identifying behaviors that led to weight gain and replacing them with new ones that promote and maintain weight loss. This can be accomplished through behavior modiﬁcation.
Managing America’s weight
To become a thinner nation, we need strategies that can help all Americans improve their food choices, reduce serving sizes, and increase their physical activity. Although successful weight management ultimately depends on an individual’s choices, food manufacturers and restaurants can help us cut calories by offering healthier foods and packaging or serving foods in smaller portions. Communities can help increase activity by providing parks, bike paths, and other recreational facilities for people of all ages. Businesses and schools can contribute by offering more opportunities for physical activity at the workplace and during the school day.
Even small changes, if they are consistent, can arrest the increase in obesity in the population. It has been estimated that a population-wide shift in energy balance of only 100 Calories/day, the equivalent of walking a mile or cutting out a scoop of ice cream, would prevent further weight gain in 90% of the population.
WHAT TO EAT?
Watch the serving size
- Pour chips or crackers into a one-serving bowl rather than eating right from the bag or box.
- Check labels to see if your portion matches the serving size on the label.
- Don’t supersize—choose a small drink and a small order of fries.
- Have a plain burger, not one with a special sauce or an extra-large patty.
- Share an entrée with a friend or take some home for lunch the next day.
Cut down on high-calorie foods
- Have one scoop of ice cream rather than two.
- Have an apple with lunch instead of a candy bar.
- Bring your own lunch rather than eating out.
- Have water instead of soda.
- Switch to low-fat milk.
Balance intake with exercise
- Go for a bike ride.
- Try bowling or miniature golf instead of watching TV on Friday nights.
- Take a walk during your lunch break or after dinner.
- Play tennis; you don’t have to be good to get plenty of exercise.
- Get off the bus one stop early.