If you ever hope to get a handle on your out of control eating habits, the first step is to get a better understanding of nutrition and what you are putting into your body. That's the first step. Once you have an understanding about the exact nature of what you are eating - and how it can affect your overall health and your weight - you can better plan meals and begin on the road to better control of your weight. So, let's get started.

Let's start at the beginning. I know some of this might be old news to most of you but, in order not to lose anyone, we will begin at the beginning. There are 3 sources of calories you can eat. They are the three "macronutrients" - fat, protein, and carbohydrate. If you eat a piece of bread, a piece of steak, or an ice cream cone you are eating calories and all of the calories come from some combination of these three nutrients. And the calories you put in your body in these 3 nutrients are part of the energy equation that, along with your genetics and other more complicated factors, determines your body weight.

While it is not as simple as some would have you believe, the energy equation basically states that:

(Energy In) - (Energy Out) = Energy Stored

What does this have to do with your weight? If we make the following connections:

Energy In (Ei) = the calories you eat

Energy Out (Eo) = the calories your body burns up

Energy Stored (Es) = the fat your store in your body

You start to see how the energy equation relates to body weight. Again, for the record, body weight is not as simple as this, but it puts things into an - admittedly simplistic - but understandable format. If you eat more calories than you burn up, then your body stores these extra calories as body fat. Let's take each item in the equation one by one.

Energy In (Ei)

This is the easy part. Energy in (Ei) is just what you think. How many calories you eat is the Ei part of the equation. The food you eat is some combination of fat, protein, and carbohydrate. There are 4 calories per gram of protein and carbohydrate; there are 9 calories per gram of fat. These are important numbers for you to remember because we will refer to them often. So what the heck is a "gram?" As a rule of thumb, a gram is about the weight of a standard paper clip. The important thing to remember is: 4 calories per gram of protein and carbohydrate; 9 calories per gram of fat.

Energy Out (Eo)

Here, the equation starts to get a little more complicated. The first misconception we have to do away with is the belief that you burn up most of your calories by exercise. Did you know that 60-70 percent of the calories your body consumes in a day are used by your body just to keep it alive? These calories are burned by repairing and reproducing the cells in your body, the activity of heart and breathing muscles, maintaining your body temperature at 98.6 degrees, and other resting functions. The burning of these calories is called your "resting [or basal] metabolic rate" or RMR. It is defined as the calories your body burns up at complete rest, lying in a bed, doing absolutely nothing. Just think: over half the calories your body burns, it burns doing absolutely nothing. The RMR for most people is about 10% higher than your metabolic rate during sleep.

The RMR (you may read in other sources the "basal metabolic rate" or BMR; same thing) varies from person to person. You already knew this. We all have that skinny friend who eats anything and everything and never gains an ounce. We also know, or may be one ourselves, who barely eats at all and can never seem to lose an ounce. It all, basically, can be written off to RMR. The RMR for each person is determined by many factors. These include how much muscle and fat your body has, your sex and your age. These factors determine 80-85 percent of the variation in RMR between people. Unfortunately, there is another big factor that account for the remaining 15-20 percent of the variation of your RMR: it's your genetics. That's right. The one thing you have absolutely no control over, your DNA.

So, if I have looked at this correctly, most of the factors that determine your RMR - namely, your sex, your age, and your genetics - are totally out of your control. But there are a couple of things you can change and that is your body composition - i.e. how much muscle and fat makes up your body. More about this later.

If you want to take the easy way out, you can go to this site on the internet and have your RMR calculated for you by just plugging in your height, weight and age. Let's do a little math now and figure what your average RMR actually is. You can estimate the calorie needs for your body to stay alive at complete rest using the following formula:

For adults males:

RMR = 66+ (6.22 x weight (lbs)) + (12.7 x height (inches)) - (6.8 x age)

For adult females:

RMR = 655 + (4.36 x weight (lbs)) + (4.32 x height (inches)) - (4.7 x age)

Since these formulas use scientific weights and measures, let's make some conversions into the more familiar pounds and inches.

For an example, let's use my measurements. I am 5 foot 9 inches tall, weigh 200 pounds and I am 54 years old. Here are the numbers:

RMR = 66+ (6.22 x 200) + (12.7 x 69) - (6.8 x 54)

RMR = 66 + 1244 + 876 - 367

RMR = 1819

For me, lying in bed, doing absolutely nothing - other than my breathing, heart beating, and maintaining a normal body temperature, I burn up 1819 calories of energy in each 24 hours period. If I stayed in bed, did nothing, and ate 1819 calories per day, theoretically I should neither gain nor lose weight. At least, in theory.

Of course, there are other variables. Some very important variables. Not the least of which is genetics. Some people, who have thin parents and thin grandparents and thin uncles and aunts and cousins, undoubtedly have a higher RMR than someone who does not. At the level of cellular and mitochondrial DNA, some people just have a higher RMR. They burn calories at a faster rate, even when they are at rest. So be it. We have to work with what we are given.

How Many Calories Do we Actually Burn…

Of course, we don’t spend our days in bed at complete rest. We all do some form of activity. To determine how many calories we actually do burn in an average day, our RMR must be adjusted upward, depending on our activity. Our adjustments must include all of our movements and activities - work home and exercise. There has to be an "adjustment factor" for our RMR. And there is.

ACTIVITY FACTORS	MALES	FEMALES
Bed-rest, chair or bed bound	1.2	1.2
Very sedentary, mostly seated with no option of moving around and little or no strenuous leisure activity	1.4-1.5	1.4-1.5
Seated work with requirement to move around but little strenuous exercise	1.6-1.7	1.6
Standing work/light exercise (e.g housework, billiards,lawn bowls golf, shop assistant)	1.8-1.9	1.7-1.8
Strenuous work or highly active leisure	2.0-2.4	1.9-2.0

If you have an office job and spend most of your work day in a chair at a desk, then your multiply your calculated RMR by a factor between 1.4 and 1.6. Pick the higher value if you walk a significant amount as part of your office job. If you work at Walmart and walk or stand most of your work day, then your adjustment factor should be between 1.7 and 1.9. If you have a truly strenuous job - for example, brick mason, construction work, or manual labor - your adjustment factor is 2.0. Your daily calorie consumption is your RMR multiplied by 2. For the job I do, mostly standing and walking, I use an adjustment variable of 1.8 (after all, my pedometer says I walk between 2 and 3 miles per day in my clinic). So, I burn around 1819 X 1.8 or about 3250 calories per day. Again, theoretically, if I eat around 3250 calories per day, my weight should remain around 200 pounds.

As we have learned elsewhere on this ABC web site, exercise plays two important roles in your daily energy consumption. The minor contribution is the 200 or 300 calories we burn up with all our sweat and heavy breathing during the exercise itself. As you can see with the 3 or 4 thousand calories we burn up daily, it’s not a major factor. But, what exercise actually does in important. It increases the lean tissue mass of our bodies. And what that does is it increases our RMR for the full 24 hours of the day. As you have already learned, our lean tissue mass - how much muscle we have - is a major determinant of our RMR. And the RMR is a calorie-burning fire 24 hours a day. So, we exercise not so much for the calories we burn up at the time but for the changes it can make in our RMR.

Tip: By the way, I have just found this company on the Internet that offers a device that will measure, with a relatively high degree of accuracy, your personal RMR. The device was reviewed in the Health and Fitness section of MSNBC so, by all appearances, it seems to be a good device. Just, FYI.

OK, so now that you know, or at least have a good estimate, about the number of calories your body burns up in a given day, you can now start making some adjustments in your diet to accomplish your goal, i.e. achieving a healthier weight and body composition.

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Albright Bariatric Clinic