Body Mass Index - classes of weight related to BMI

This table merely shows you where you want to go. This is it! This is your goal—a BMI between 20 and 24—not more, and certainly not less. But to get to that goal, you have to figure out how many calories that you burn and have an idea about how many calories you consume daily.

Calories in and calories out

The basics are quite simple, calories in minus calories out equals either fat stored or fat burned. There are no exceptions to this rule. Your body is no different from mine, your metabolism isn’t slower, and your body is not fed at night by evil angels. Moreover, honestly, it doesn’t matter when you eat, it matters what you eat. You can eat all of your food right before you sleep, and other than a bit of nighttime reflux, heartburn, and discomfort, what matters is how many calories that you consume, not when you consume them.

Basel Metabolic Rate (BMR) - Calculate the calories you burn

The first thing that you have to do is become aware of how many calories your body will require to function. For some this is a revelation. Yes, our body requires calories to do some basic work—it requires calories to breathe, calories for the heart to pump, calories for the brain to work, calories to walk, calories to shiver, and even calories to digest food.

We call these functions the basal metabolic rate or BMR. The BMR is a function of a number of factors including age, weight, gender, and so forth. We can make some broad assumptions and come up with a number that will be pretty close to what your body will require.

There are many formulas to determine your BMR but in our workbook we use a pretty simple one. Some machines, called body composition analyzers, can help you determine your BMR. One is made by Tanita (www.tanita. com). These are quite expensive, although a number of physician’s offices have them. Here is a formula to help you see how a number of factors make up your BMR.

A. The number next to your level of activity = A

•  working out more than once a day=1.9
• work out daily with an active lifestyle=1.7
• exercise 4-5 times a week=1.5
• exercise up to three times a week=1.3
• very sedentary=1.2

B. Weight in pounds = B

C. Age in years = C

• 18-39=1
• 40-46=.95
• 47-50=.92
• 51-55=.90
• 56-60=.85
•  61+ =.80

The formula

B x 10 x A x C = Your Basic Metabolic Rate

You can see by this formula that as your weight decreases, so does the amount of calories it takes to sustain it. Very heavy individuals can lose weight fairly easily because it takes a lot of calories to sustain that weight. One of my dear friends, Kirk Thompson (who I call my son)— weighed 750 pounds when he had weight loss surgery. If we were to calculate his BMR it would go something like this:

750 pounds multiplied by 10 multiplied by his activity level (1.2) and by age factor (1).

This meant it took 9000 calories a day for him to sustain his weight. That is a lot of food! If he ate more than 9000 calories he would gain weight, and if he ate less he would lose weight. Some 450 pounds later, Kirk has a much smaller stomach and a much lower BMR. Today he weighs 300 lbs, so his BMR today is 3900 calories a day. He still needs a lot of calories to maintain his weight, and that explains why he is still losing weight. It is a lot easier to lose weight when you have such a high requirement than it is when you weigh less.

Notice something about the BMR formula—the more active you are, the higher your caloric needs are. Why is that? Sure, if you run around a lot more you will be thinner— most children run around all summer long and see their ribs. As one ages and jobs and lifestyle become more sedentary, the ribs become covered. There are two benefits to being active: muscle uses more calories than fat—just having muscle means you will use more calories. Athletes eat a lot of food, and they have to in order to maintain those muscles. In addition, as the athletes work out a lot their activity level is quite high. The second benefit is the long-lasting effect of exercise: after you have done some mild exercise your body is still more active—and being more active you will burn more calories at rest than someone who didn’t exercise.

Increasing activity is one of the easiest ways to lose weight. In fact, it is one of the common themes we have learned from successful patients. All successful patients exercise—no excuses. There are plenty of forms of exercise, but that is for another chapter.

“If you want to be 130 lbs., then you have to eat like someone who weighs 130 lbs.”

By this point you probably have figured out your BMR. That is, how many calories it takes to maintain your weight. Just for fun, find out what your BMR would be at your goal weight. Do you see the difference in calories between your current weight and your goal weight? Jessie Ahroni, a 135-pound 56-year-old female who had a lap-band placed six years ago, says it very simply, “If you want to be 130 pounds, you have to eat like someone who weighs 130 pounds.”

The knowledge of how many calories it takes to maintain your weight will help you determine how many fewer calories you need to eat in order to lose weight. Here are a few simple numbers: it takes about 3500 calories to make a pound of fat. So, if you eat 500 calories above your BMR for a week, then you would gain a pound in that week. In a year you would weigh 52 pounds more than you weigh now. Want to lose 52 pounds in a year? Then do the opposite. You need to burn 500 more calories every day than you eat. “Eat less, move more.”

Technically there is more to it. Often BMR is referred to without the activity level. When the BMR is multiplied by the activity level, we have the total energy expenditure (TEE). In this book we factor those together and call them BMR. Time to figure out how much you can lose and how quickly.

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