Calories and Basal Metabolic Rate (BMR)
Calories measure energy. They are determined by burning a measured portion of food and measuring the amount of heat (or calories) it produces.
The number of calories you need depends on your Basal Metabolic Rate (BMR), your level of physical activity, and the energy you need to digest, absorb, and metabolize food.
Your BMR is the energy your body needs while awake and at rest. It varies with each individual, but can be generally determined by the following formulas:
Male BMR = 66 + (6.21 × your weight in pounds) + (12.7 × your height in inches) – (6.8 × your age)
Female BMR = 655 + (4.37 × your weight in pounds) + (2.32 × your height in inches) – (4.7 × your age)
To determine your daily caloric needs, multiply your BMR by the number that best represents your activity level:
| Activity Level | BMR Multiplier |
| Sedentary (little or no exercise) | 1.2 |
| Lightly active (light exercise 1–3 days per week) | 1.375 |
| Moderately active (moderate activity 3–5 days per week) | 1.55 |
| Very active (heavy exercise 6–7 days per week) | 1.725 |
| Extra active (professional athlete) | 1.9 |
Weighing Your Risk
Most people already know if they are at their ideal weight. You can see it in the mirror. But you can have a more accurate indication of how your current weight stacks up to your ideal weight.
First, determine your body frame size. Medium frame males have a seven-inch wrist. Medium frame women have a six-inch wrist. Larger frames have larger wrists, and smaller frames have smaller wrists. Now add up the pounds to determine your ideal weight:
Medium Frame Males 100 pounds for the first five feet of height 5 pounds for every inch over five feet take away 5 pounds for every inch under five feet
Medium Frame Females 106 pounds for the first five feet of height 6 pounds for every inch over five feet take away 6 pounds for every inch under five feet
Smaller frames subtract 10 percent
Larger frames add 10 percent
Weigh the Results
Now that you have a general idea of where you stand, you can begin to adjust your diet accordingly.
Essential
Keep challenging yourself. Taking the same walk day after day will only help you for so long. As your body becomes accustomed to the motion, and your muscles develop, the movement is no longer challenging, and your heart is no longer working hard. Pick up the pace, take a hill, or start running.
To lose weight, your calorie intake must be less than your current daily caloric needs. To gain weight, it must be more.
To lose weight (which is the more common goal), you need to burn about 3,500 calories more than you consume. This can be accomplished by eliminating these calories from your diet, burning more calories through exercise, or both.
For example, walking fast (so you’re breathing heavily) for 15 to 20 miles a week will burn about 2,500 calories. As your fitness improves, you must increase the intensity or duration of your exercise to maintain the weight loss.
