I tend to go off in all directions when it comes to goals: this number on the scale, this BMI, this level of exercise, this frequency of exercise, this calorie consumption, elimination of this sweet treat, this processed food, this restaurant. But I'm going to erase most of that from my mental chalkboard (oh, you don't have a tabla rossa? I highly recommend. I picture taking a sleeve and smearing it across the chalkboard--true, it's messy, but it's vehement!). What I'm leaving on the list is a healthy BMI. This actually requires I meet a few of those other things (that healthy BMI doesn't just magically happen because I want it to), but it's best just to keep my head down and push forward on all of those.
Basically it boils down, as we all know, to two things: eat fewer calories, and burn more calories. One pound equals 3500 calories, so in order to lose a pound a week, you need to either cut out 500 calories a day, or burn 500 calories a day, or some combination thereof. Simple, right? Well, sort of. I'm going to let you in on the basics I have learned through the classes I took at Colorado Weigh, which is a fabulous program that I can't recommend enough. Every one of the 100 pounds I lost was a direct result of what I learned there. Unfortunately, they rarely offer classes to the public anymore, and if you're not in Denver these aren't available anyway.
First you need to figure out what your resting metabolic rate, or basal metabolic rate is. This is not exact (the best way to do that is water displacement, but that's kind of thing isn't available to most people, and this is close enough). Go figure it out, I'll wait.
Got it? I'm at 1515 calories per day (jeepers, that seems low!). Ok, so this is the amount of calories you burn if you were to slug it all day in bed, not moving. Basically what your body needs to perform it's vital functions. This number is important, because if you don't eat this, your body thinks "Hey, where's my energy! Uh-oh. I'd better slow things down--I've got to make what I get last!" Obviously this is counterproductive to weight loss. So if I were to just reduce my calories by 500 calories a day, I'd be at 1015 calories a day. This is waaaay too low. My body puts on the brakes (yours will too) if I go below 1200 calories. No one should consume fewer than 1200 calories. Got it?
I'm going to stick with consuming around 1500 calories. This means any energy that I burn, either through incidental exercise or during an actual workout, will be above and beyond what I'm consuming.
So here's where that pedometer (you know, the one you got in a happy meal--I mean healthy meal--one time) comes in. It factors all of the calories you burn through incidental exercise. How much you move during your day just walking around. This counts in that 500 calories I have to burn--woohoo! This is the part that experts talk about when they say park your car further away from the store, take the stairs instead of the elevator, etc. And yeah, it works in that way, but I'm afraid there's more to it than that. You need to calculate your steps per calorie, which is a chart that factors your height and weight and gives you a number of steps per calorie. Mine is 20 steps per calorie. This means I have to take 20 steps before I burn a single calorie. To put this in perspective, 100 pounds ago my steps per calorie were 12. The less you weigh, the more energy you have to expend to burn the same amount of calories. Bummer, I know.
Today I walked about 7,000 steps. For me, this calculates to 350 calories burned through just walking around. Then I went for a short run after I got home (yay me!), where I burned another 450 calories.
So, here is where the math comes in. My total energy expenditure for today is my RMR (1515), plus energy burned (800 calories) = 2315. In the snapshot of just today, in order to maintain my current weight I would have to consume 2300 calories. Less than this, I lose weight, more than this I gain it. So if I subtract 500 (the amount of calories I need to reduce my intake by in order to lose weight) from 2315, it gives me 1815. In theory, if I were to consume 1800 calories a day and burn 500 calories through physical activity or incidental exercise, I would lose a pound a week.
But it isn't always that simple, is it? First of all every time you lose weight (even five pounds or so) you need to re-do these calculations, because as you lose weight your steps per calorie changes. Secondly, fat is more difficult to burn than carbohydrates. There are 9 calories in a single gram of fat. In either a gram of carbohydrates or a gram of protien, there are only 4 calories per gram. So for my body to burn a single gram of fat (assuming my glycogen stores are depleted), I need to walk 20 x 9, or 180 steps. A single gram. That's like nothing. You can make the scale register a gram if you blow on it kind of hard. But even getting to the burning of that gram isn't easy. In training for my half-marathon I learned a lot about glycogen, which is your muscles' energy source. You have to deplete this energy store before your body will begin dipping into its fat stores. The fastest way to deplete it is through high intensity exercise. Also, the faster you go, the more you burn in less time. Can you see now how I might have gotten into running?
At some point after I did these calculations in class, I realized that I was going to have to walk about 22,000 steps a day (based on calculations) in order to reach my goal. This, needless to say, was daunting. There just aren't enough hours in the day to get that much walking in, particularly if you work an office job. But there was this great option--I could kick up the intensity, which would burn more calories faster. Lightbulb!
Essentially, all these calculations are a nice way to track your progress, and to adjust your goals as you move along. For me they were the mode by which I realized I had control over what I weighed. They were the tools that got me up off the couch and onto a treadmill at the YMCA. I always think of what Maya Angelou has said: "I did then what I knew how to do. Now that I know better, I do better." Even with weight loss, it applies. Now that I know exactly how to do the math, I know that weight loss (or gain) doesn't just happen by magic.
It might seem daunting to some to have to live within the confines of a particular goal, either in consuming fewer calories or burning more of them (or more often than not some of each). But knowing that the answer is in your grasp, and the ability to change how you feel and how you look is in your control--to me that cracks the world wide open with possibilities.
(Gah--I feel like I just vomited out the hideously deformed baby of a 12 step program leader and a motivational speaker that sells his own tapes on 2 am informercials. I didn't mean for this to turn out quite so earnest. I'm tired. I'll try for more sass tomorrow, ok?)