Most people understand that in order to lose weight, you have to use more calories than you’re taking in. It’s the principle of energy balance: if you consume more than you burn, you’ll gain weight; if you burn more than you consume, you’ll lose weight.
Of course, there are a lot of factors that complicate that very distilled explanation, but that’s the core of the matter. So in an increasingly overweight world, billions of dollars are spent trying to find a painless, magic combination for the two-pronged prescription for weight loss: diet and exercise. Some of us devote our lives to the search for the most painless way to eat less and move more so that we can lose weight, improve our health and feel good.
For many people, it could actually be much easier than the awful challenge they’ve anticipated, but it would help to understand the two parts of the weight-loss prescription and the roles they play. Research shows that for most overweight people, the prospect of exercising is the most daunting obstacle in any weight-loss attempt. That’s not surprising. Starting a workout regimen can make a person feel quite vulnerable. Most of us feel a little uneasy starting something new, even when it doesn’t involve something as personal as our body image. And for most overweight people, physical activity is a pretty unfamiliar experience, or at least a long-lost one.
On the other hand, we’re all familiar with the dietary side of the equation. Everybody eats. And mentally, it’s less of a challenge to contemplate changing what you’re already doing, than it is to imagine starting something that’s not already part of your life, like working out. So of the diet/exercise duo, the dietary changes usually seem less threatening to people.
And the good news is that the way to start losing weight just happens to be in the diet, not in the daunting exercise component.
Here’s why: Most people understand the energy balance principle in theory, but they don’t understand how much activity it actually takes to burn off say, a hamburger and fries. And they don’t realize that the main purpose of exercise in a weight management program is not really to burn off the lunch you’re eating today, but to retool and train your body’s systems so that they’re better at burning up the lunches you’ll be eating a month, a year, or two years from now.
Consider: Exercise alone won’t take off 50 pounds of excess weight. That would demand a phenomenal caloric output, one that would literally be impossible for most of us. That’s because the majority of the energy we burn is used up not in our physical movement and activities, but in simply metabolizing our fuel and supporting essential systems.
For instance, you’ll burn about 100 calories in an hour of good walking. But you’ll burn about 60 calories in an hour of good sitting around!
If you’re trying to take weight off, you’ve got to adjust the diet, and as we’ve noted, most people really find that an easier place to start. I often have patients start with a dietary approach alone. Once their dietary changes have easily taken off a few pounds—without exercise—increasing their activity level doesn’t seem so intimidating. In fact, most people are raring to go, excited to see what a difference it will make to increase their energy expenditure.
And what researchers have found is that when people add 30 minutes of moderate intensity activity each day—taking three 10-minute walks, for instance—the biggest difference shows up for people who had been unfit and sedentary. Their cardiovascular fitness levels were twice as good as folks who did not undertake the 30 minutes of activity, and their death rates were half those of their inactive counterparts.
But there is a point of diminishing returns with the exercise. Health effects improve commensurate with the amount of activity, up to about that 30-minute point. But increase the time to 40 minutes, and researchers found that measures of fitness on average people only improved about 10 to 15 percent for that 25 percent more activity.
And interestingly, the exercise effect doesn’t show up much in initial weight loss results at all, with the data indicating that the added exercise only accounted for about a one- to two-pound additional loss over a six-month period.
But before you decide that it’s not worth the effort, remember what we said about the purpose of exercise in a weight management program. It’s not to burn up your lunch, it’s to train your body to burn all your lunches better. This is borne out in study after study showing that while exercise doesn’t make much difference in initial weight loss, it’s absolutely essential to maintaining a loss.
That’s because along with the improvements in cardiovascular health, pulmonary function, immune health, reduced risk of diabetes and hypertension and all the other health benefits, remember that the exercise is making your body burn more calories in general, ramping up the metabolic rate so that your body is naturally burning more, even during those minutes of good sitting around.
While I encourage everyone to become more physically active eventually, it’s actually not a good way to begin for those whose bodies are extremely stressed by their excess weight. When people have started to have improved health and better mobility just from their dietary changes, it will be both safer and more appealing to start a gentle exercise regimen.
But no two people are the same, so it’s fortunate that scientific breakthroughs are making it easier to tailor a solid, medically based weight-loss program to the individual physiology of each patient. And while modern conveniences have removed most of they physical labor from the average person’s lifestyle, they’ve also enabled us to have access to fresh fruits and vegetables year round, so it’s not too hard to enjoy a well-rounded diet, even as we’re cutting back on how much we eat.
But if you are that unusual individual who simply does not want to change eating habits and prefers to just try to “work it off,” you’ve got your work cut out for you.
With that average of 100 calories burned in an hour of walking, you could start your day at 6 a.m. with your favorite McDonald’s breakfast, weighing in at just under 600 calories. If you started walking right after breakfast, you’d burn that off right about lunch time. And if you had two slices of pizza and a soda for lunch, then started walking again, you’d have that burned off by about 6:30 or 7 p.m., when you’d better plan on having a light dinner, because there just aren’t that many hours left in the day.
Through Thick and Thin:
When we talk about energy balance, it’s not just a matter of numbers in, numbers out. You’ve got to have a balanced lifestyle, too. Eating better—and eating less—is the way to start losing weight, but exercise is essential to teaching your body how to burn calories more aggressively, so you can keep the weight from creeping back on.