I was always pretty good in math --- word problems, algebra, probability and statistics (though geometry did give me some trouble) --- so why can't I figure this out? The amount of calories you take in minus the amount you burn off equals your current weight. Simple, elementary math!
Or so it seems --- now I understand what they mean by applying the math. Seems that's where I am having my biggest problem. I understand the concept, but somehow I am just not applying it to my life.
Here's a Word Problem:
If Maryee weighs X pounds and she wants to lose 40 pounds and she eats an average of 1600 calories per day, how much exercise does she have to do to lose that much weight?
Solving the Problem:
*There are approximately 3500 calories in a pound of stored body fat.
*And, for every pound of weight you carry, you burn about ten calories per day.
So, a person who weighs 150 pounds would need to burn 1,500 calories each day just to remain at that weight (that would be his/her BMR - basal metabolic rate - the number of calories your body burns at rest to maintain normal body functions.) So, to lose weight, this person needs to have a combination of calories taken in (through food) and calories burned (through exercise) that would be less than 1,500 per day.
[So, based on my weight, I can figure out the amount of calories I need to stay at this weight - weight in pounds x ten - or to lose weight]
*According to a health website, a healthy daily caloric intake for women who want to maintain their weight is 1800 and for women who want to lose weight, it is 1500
And as a general guide, the American College of Sports Medicine (ACSM) recommends that calorie levels never drop below 1200 calories per day for women or 1800 calories per day for men --- even these calorie levels are quite low.
*The CDC website says that it takes approximately 3,500 calories below your calorie needs to lose a pound of body fat. To lose about one to two pounds per week, you'll need to reduce your caloric intake by 500-1000 calories per day.
So, if I create a 3500-calorie deficit through diet, exercise or a combination of both, I should lose one pound of body weight. (On average 75% of this is fat, 25% lean tissue.) And in order to lose one to two pounds per week, I need to reduce my caloric intake by 500 - 1000 calories per day.
A 3500 calorie deficit is a good amount - I can see why they spread it out over a week.
In order to figure out the amount of calories that are burned doing a particular activity, you must take your weight into consideration. So using a calorie burning calculator, according to my weight, here are some ways for me to burn calories:
- - Jogging for 20 minutes burns 180 calories
- - Running at 5 mph for 20 minutes burns 217 calories
- - Walking at 3 mph for 20 minutes burns 112 calories
- - Walking upstairs for 5 minutes burns 51 calories
- - Swimming for 30 minutes burns 234 calories
- - Low-impact Aerobics for 30 minutes burns 234 calories
Okay, so I think I have solved the problem. Clearly this is going to have be a combination of reducing my caloric intake and increasing my level of exercise to burn calories --- and yes, it is going to take some time to reach my goal.
I understand the concept. Now I need to start applying the math!
Published On: February 22, 2010