Weight Loss

I cannot recall a time I was really concerned about my weight until this year. I just assumed that my rapid metabolism would take care of anything I threw at it. So when I went home for Christmas this past December, I was shocked to find that I had gained 10 pounds in about six months, after a period of many years of stability. In retrospect, it was not very surprising considering how much I indulged in ice cream and food, especially given how little I exercised (cue the old refrain about being too busy). Even though I felt a little more sluggish and knew that my belly protruded a little more than usual, it required the turn of the tens digit to really do a number on my complacency.

Desiring to turn a new leaf, I made a New Year’s resolution to “eat less, move more.” I made the conscious decision to eat a little less than what I would normally eat, which was slightly more than comfortably full; and to hit the gym at least twice a week. So far, I’ve lost 5 pounds in about five weeks while gaining muscular strength, without going crazy over either dieting or exercise. I discovered a while ago that consistency is the most important factor in achieving one’s goal, and it isn’t as difficult as one expects. The reason I had been so reluctant to go to the gym had more to do with motivation and psychology than with the lack of time, but that motivation quickly changed when I realized how easy it was to fall into a habit that increases the risk of health problems. So for me, awareness got me on the fast track of correction.

So exactly how easy is it to say “No” to culinary temptations and to set aside a few hours a week to go exercise? And how well does it correspond to a healthy weight loss rate (1-2 lbs/week)? An engineer at heart, I was curious about the mathematics behind weight loss, so I decided to do a back-of-the-envelope calculation. Here is what I found:

My gym routine consists of 3 lifting exercises for the large muscle groups (bench press, squat, and lat pull), usually to failure on the third set, and then I run at least one mile on the treadmill. According to the treadmill, I burn 150 calories per mile. So assuming lifting weights is equivalent to about 2 miles, one workout is about 450 calories. I go to the gym a little more than 10 times a month. So that’s a delta of 5000 in caloric expenditure per month.

If instead of eating dessert everyday, I eat dessert every three days, I lose about 5000 calories as well (a Drumstick is about 270 calories). Furthermore, if I eat one fewer bowl of rice every three days, I lose an additional 2000 calories. So in total, that’s a delta of -7000 in caloric intake per month.

If all 12000 calories are lost in the form of fat, then I would have lost about three pounds, which is within a factor of two to how much I actually lost (assuming, of course, that my weight would be stable if I had not changed my eating and exercising habits). The discrepancy can most likely be attributed to an increased resting metabolic rate1.

So by being just a little more disciplined, I (and I suspect most people) can lose weight at a healthy rate and develop a habit of better eating and exercise that ensures it stays off. Whether someone makes the effort really comes down to how important health is to him/her.

1 I suspect the increased resting metabolism more than offsets the calorie/protein conversion. That is, 1000 calories can be converted to 250g of protein or 110g of fat, but the 250g of protein in the form of muscle will burn additional calories.