Some people just can’t muster the willpower to change their eating habits for the sake of losing weight. Does this mean they are fated to remain overweight for the rest of their lives? No, it doesn’t. As long as you are willing to maintain a consistent, intensive exercise habit, you can achieve your ideal body composition without changing your eating habits.
It’s a simple game of math. No matter how many calories you eat, it’s a finite number, and probably not more than 3,500 to 3,800 per day. Exercise, as we all know, burns calories. The specific rate at which it burns calories depends on its intensity, but at any intensity level, the total number of calories you burn daily though exercise depends on how much time you spending working out. If you spend enough time working out, you will burn more calories than you consume, and you will lose weight. There are no exceptions to this principle.
Scenario 1: Dieting Only
Let’s look at a hypothetical example to see how exercise-only weight loss works in a fairly typical case. Suppose you currently weigh 200 pounds. Your ideal body weight is 150 pounds. You do not exercise currently. Using this information, you can use an online calculator such as the one here to produce an estimate of the number of calories you need to consume daily to maintain your present weight. This figure also serves as an estimate of the number of calories you’re actually burning each day (supposing you are not currently in a period of weight gain). In this case, the result produced is 2,818 calories per day.
So we now know that you are consuming and burning roughly 2,818 calories per day. Since your goal is to lose 50 pounds, we now need to calculate how many calories per day you would need to consume at the same activity level to get down to 150 pounds. Using the same calculator, the figure we come up with is 2,114 calories per day. What this means is that you would have to reduce your daily caloric intake by 700 calories to reach your goal body weight of 150 pounds.
What this calculator does not tell you is how long it would take. To do that we need to make another calculation. For every 3,500 calories your body burns and does not replace with food, you lose one pound. Thus, with a caloric deficit of 700 calories per day, you could expect to lose one pound every five days. It will then take you almost 36 weeks to lose 50 pounds. Or will it? Actually, it would probably take a lot longer, because a caloric deficit of 700 calories per day will cause your basal metabolic rate to slow significantly as your body chemistry goes into starvation food and adapts in order to “cling” to every calorie you swallow. This slowing of metabolism effectively decreases the number of calories you need to maintain your current body weight, which in turn effectively shrinks the caloric deficit you achieve by consuming only 2,114 calories per day. In addition, weight loss itself reduces the number of calories your body burns each day, compounding the problem. As a result, the longer you diet, and the more weight you lose, the lower your rate of weight loss becomes.
It is not possible to accurately estimate how much time these factors would add to the process of losing 50 pounds, but let’s just throw out a ballpark guess of 6 weeks. So now we’re looking at roughly 42 weeks to drop from 200 pounds to 150 pounds through dieting alone.
There’s another problem, however, with trying to lose 50 pounds by remaining sedentary and decreasing your food intake by 700 calories per day: it would make you miserable with hunger. That’s why very few people are able to permanently lose such substantial amounts of weight without exercising.
Scenario 2: Lose Weight Through Exercise
Now let’s see how much exercise you would have to do to reach your goal weight of 150 pounds without reducing your food intake. The same guideline applies: for every 3,500 calories you burn through exercise, you will lose one pound. The difference is that this will never change, because your metabolism will not slow down and because a calorie’s worth of exercise remains a calorie’s worth of exercise, no matter how much weight you lose. True, you will burn fewer calories per minute of exercise at any given intensity level as you lose weight, but you will make up for this effect by increasing your intensity level as you become fitter.
Let’s suppose your chosen form of exercise is jogging. At your current weight of 200 pounds, you will burn roughly 900 calories per hour spent jogging. If you jog 6 hours per week, it will take you approximately 32 weeks to reach your goal weight of 150 pounds, assuming you increase your running pace gradually over that time period as you lose weight and gain fitness.
Now, to be realistic, we can’t assume that you would be able to begin jogging an hour a day, six days per week, after not having exercised at all recently. If we assume a 4-week ramp-up period is required to get to that level, then we’re looking at 36 weeks to lose 50 pounds through exercise alone versus 42 weeks to get the same result through dieting alone (assuming you could resist hunger and stay on the diet!).
And let’s remember: If you used exercise to drop from 200 to 150 pounds, you could continue eating roughly 2,818 calories per day and maintain your body new, ideal body weight, whereas you would have to continue eating a meager 2,114 calories per day to maintain the same weight without exercise.
There are some people in the world who hate exercise so much that they would rather go hungry to lose weight than jog six hours per week so they could lose weight without changing their eating habits. But research has clearly demonstrated that very few people are able to maintain large amounts of weight loss without exercise.
The fact that it is possible to achieve permanent weight loss on an all-you-can eat diet is poorly understood by the general public. That’s a shame, because for the large number of men and women who cannot muster the willpower to eat less or give up their favorite high-calorie foods, exercise-only weight loss is the only realistic way to achieve their ideal body weight. As a man who has done just that in his own life, I wrote this article series to provide encouragement for others like me.