Crunching the Numbers

continued from Bread 'n Molasses magazine (Oct/Nov 2007)

Click here to find out where to buy the magazine to read the entire article.

At the beginning of this article we learned how to calculate your BMR (Basal Metabolic Rate) and how to determine the number of calories you need to consume on a daily basis in order to maintain your current weight. What if you want to lose weight? A good rule of thumb is to reduce this number by no more than 20%. If for example the BMR calculation gives you 1700 calories to maintain your weight, then divide that by 5 to determine 20%. The answer is 340, so you should aim to eat no less than 1360 calories /day (1700 – 340).

If using an online BMR calculator look for one that takes into account your activity level, often referred to as the Harris Benedict Equation.

Reduce by too much too quickly, and it’s not going to work. Overkill will mess up your metabolism and send your body into starvation mode. Drastically depriving yourself of food decreases your BMR, so your body doesn’t burn as many calories just standing still. The American College of Sports Medicine (ACSM) recommends calorie levels never drop below 1200 per day for women or 1800 for men.

A realistic safe amount of weight to lose is one to two pounds per week. This may not sound like a lot but to be successful you must set realistic goals. Losing at this rate also means you’re more likely to keep it off.

Okay so let’s see what reducing your calories by 3500/week would look like. From the magazine article we learned that 3500 calories equals 1 pound of stored fat. You can do this by reducing your caloric intake, or burning off more calories through exercise, or both (preferable). 3500 broken into 7 days is 500 calories/day. You’ve already decided to cut your caloric intake by 340/day so now you just have to go for a brisk half-hour walk each day or do 25 minutes of resistance training and you’ve got the 500 calories/day conquered! Double your exercise and you’ll lose 2 lbs/week. At this rate, you’ll be 20lbs slimmer by New Years Day! And you’ll feel healthier and look fitter.

Using a food journal either in a notebook or an online food journal is a great way to help keep you on track. Write down everything you normally eat in a day and calculate the calories you’re consuming. A few good ones are SparkPeople.com and FitDay.com.