Unlike what you hear from the thousands of diet peddlers or the diet drug companies, losing weight is actually very simple: take in fewer calories than you burn each day. But, how many calories should you be consuming? That question was answered almost a century ago by Harris Benedict and is referred to as your Basal Metabolic Rate (BMR). BMR is defined as the number of calories your body consumes at rest to maintain your current weight. To determine your BMR, use the following formula:
Women: BMR = 655 + (Weight x 4.35) + (Height x 4.7) - (Age x 4.7)
Men: BMR = 66 + (Weight x 6.23) + (Height x 12.7) - (Age x 6.8)
*Weight is in pounds and height is in inches
Once again, your BMR is simply the number of calories used by your body to sustain life. Since lifestyles vary widely, you must apply a multiplier to find the approximate number of calories that you actually burn each day. I recommend using a sedentary (1.2) or light activity (1.375) multiplier since most people fall into these categories but tend to overestimate their activity level by as much as 50%. Therefore, to find your approximate calorie requirements, multiply your BMR by your activity level. Because I am a 38 year old, 5'8", 155 pound male, my BMR works out to:
BMR = 66 + (155 x 6.23) + (68 x 12.7) - (38 x 6.8) = 1636.85
Calories needed to support 155 pounds (sedentary) = 1636.85 x 1.2 = 1964.22
In order to lose weight, you must either consume fewer calories than your body needs to sustain its current weight or burn more calories through various activities. As you may have heard before, a combination of diet and exercise works best.
It may be easier to think of your daily diet as a checking account. The major difference being instead of having overdrafts and financial problems as your punishment for overspending, you get something much more dangerous: weight gain and obesity.
The good news with your calorie account is that it fills up every day with a certain number of calories you can spend. For me, that number is around 1964. This is the approximate number of calories my body will burn if I do little else but go to work and sit behind my computer all day. Therefore, if I only ingest 1964 calories, my diet is in balance and I neither gain nor lose weight.
In the same manner, let's say I needed to lose a few pounds and I am only taking in 1664 calories; I know that there are 3500 calories in a pound of fat. In a little over 11 days, I will lose a pound of fat. That's not very fast you say. Well, all I had to do to lose that pound was switch two cans of your average soft drink with diet drinks or, better yet, water.
However, say I really like cookies and I take in an extra 300 calories. Now I have to work a little overtime to pay for this and, for your diet, this means exercise. Never fear, without much effort I can burn the calories with a brisk 20 minute walk.
Ok, so it's not that easy. Let's say I hate to exercise and I think I don't have 20 minutes to walk. Incorporate the walk into your daily life. Instead of finding the parking spot closest to the store, pick one farther away and avoid the door dings. Go one further and walk to the store if possible. Instead of using the elevator or escalator, use the stairs. Simple things like these will add up: play catch with your kids, work in your garden, or just stand sometimes instead of sitting (you'll burn twice as many calories).
Removing the mystery behind diets and weight loss is the key to successful weight control. It's important to remember that your diet is not something that you start and finish or can cheat. Your diet is with you every day for the rest of your life. To control your diet, you should know your BMR and how many calories you have to burn each day. When losing weight, either eat fewer calories than your modified BMR (BMR x Activity Level) or increase your physical activity. A combination of eating less and doing more generally works best.