Staying healthy means following a well-balanced diet and staying active enough to maintain a healthy weight. Television, the Internet and magazines are filled with "tricks" and advice on how to stay fit and thin. To maintain a healthy weight, you must burn off the number of calories you consume each day. Understanding the relationship between energy intake and expenditure can help you can achieve a healthy balance.
Every calorie you eat has the potential to turn into energy. If you want to maintain your weight, you must match your calorie intake with your expenditure through physical activity. When you eat more calories than you use, your body does not get rid of them. Instead, your body saves these calories as fat for later use. If weight loss is your goal, then tipping the balance toward a daily caloric deficit is necessary. Eating less than your body uses forces your body to use its stored energy, burning fat and reducing your weight.
Your weight influences the energy needs of your body. An easy way to assess your weight is through the BMI scale. It does have its limitations, but the body mass index scale is an easy way to determine your body composition. To determine your BMI, divide your weight in pounds by your height in inches squared, then multiply by 703. If your BMI is less than 18.5, you are underweight. A BMI between 18.5 and 24.9 is considered healthy, while a BMI between 25 and 29.9 is overweight and 30 or greater is obese.
Physical Activity Recommendations
According to the American College of Sports Medicine and the American Heart Association, there is a minimum amount of physical activity you must participate in to maintain your health. All adults between the ages of 18 to 65 need to achieve 30 minutes of moderate intensity aerobic activity at least five days per week. Vigorous activity can also be done, in this case, recommendations are to exercise for 20 minutes, three days per week. However, if weight loss is your goal, you will need to increase both the duration and frequency of activity until weight is lost. This means you must burn off more calories than you consume in a day. To safely lose 1 lb. per week, you would need to reduce your caloric intake by 500 each day through a combination of eating less and exercising more.
To understand how many calories you need to eat, you must estimate your metabolic rate. Resting metabolic rate is the number of calories your body uses at rest. Once you determine this amount, then you can understand how to form your healthy diet around the energy your body needs. For a female, resting metabolic rate is determined with this formula: (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161. For men, resting metabolic rate equals (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5.
To maintain a healthy weight, your energy intake should reflect your energy expenditure. Take into account your level of activity by multiplying your resting metabolic rate by your activity factor. If you are sedentary, multiply your resting metabolic rate by 1.2 or for light activity multiply by 1.375; for moderate activity, multiply by 1.55. If you are very active, participating in exercise six or seven days per week, multiply by 1.725. For extreme activity such as daily exercise or a very physically demanding job, multiply by 1.9.
- Centers for Disease Control: Caloric Balance; February 15, 2011
- Centers for Disease Control: Healthy Weight: About BMI For Adults; June 2, 2011
- "Circulation"; Physical Activity and Public Health: Updated Recommendations For Adults From The American College of Sports Medicine and the American Heart Association; 2007
- Calories Per Hour.com: Calculating BMR and RMR