We’ve all heard the saying “weight loss is 20% exercise and 80% diet.” But is that really true? When it comes to shedding those pounds, which change to our lifestyle really matters more? Diet? Or Exercise?
Let’s start with exercise:
Point: While you can lose weight with diet alone, exercise is still a major component. Without exercise, only a portion of your weight loss actually comes from burning fat (the rest is muscle and bone density – you’re body doesn’t discriminate what it uses up for energy). Since working out stimulates the growth of both of those tissues, losing weight through exercise alone means you’re burning mostly fat while retaining or even building more muscle. The number on the scale may not drop as fast (or may even grow in some cases – since muscle takes up less space than fat), but you will look smaller and your clothes will fit better. (Want to know more about my thoughts on the scale? Try reading: My Problem with the Scale)
Counterpoint: Exercise alone without a calorie deficit is almost useless when it comes to losing weight. Researchers tracked people who added more workouts to their current training routine but kept their diets the same and found they lost only a few pounds. I.E. exercise is only great as a weight loss intervention tool when it is combined with a change in diet. Our energy systems are a lot more complicated than that age old “calories in versus calories out” equation, so it’s hard to create a calorie deficit with just exercise alone.
Counterpoint #2: (What?! I can’t come up with another point!) To lose just a teeny tiny measley pound, you need to achieve a 3,500 calorie deficit. Dieting is more effective than exercise at doing this because it takes a lot and i mean A LOT of activity to create a 3,500 calorie deficit through working out. Essentially, you’d need to run 7-10 miles a day to lose one pound a week.
Another Counterpoint: Exercise accounts for only a small percentage of our total daily calorie burn. Fewer than 30% of the energy we use up comes from exercise. We actually burn more calories doing everyday things like breathing, digesting, sleeping, and well – LIVING! (Want to know more about the calories you burn in your every day lives? Try reading: I’ll Take my Exercise N.E.A.T.)
And Yet Another Counterpoint: The University of Utah’s Nutrition Clinic analyzed more than 700 weight loss studies and found that people see the biggest results when they simply EAT SMART. Sounds so easy right?? Well, on average, people who dieted (for 15 weeks) without exercising lost 23 pounds while those who exercised (for about 21 weeks) without dieting lost only 6. Moral of the Story: It’s much easier to cut calories than to burn them off later.
ANDDDDDD My Fourth Counterpoint: More exercise doesn’t necessarily mean more calories burned. While the theory is still up for debate, scientists found evidence that after a certain amount of exercise your energy output plateaus. So just because you ran 4 miles today versus 2 yesterday, it doesn’t mean you burned twice as many calories.
Soooo, while both diet and exercise are both important for long-term weight loss (and I definitely suggest you incorporate exercise into your everyday life – not just for weight loss but for its many physical and cardiovascular benefits), the real overwhelming takeaway here is:
You can’t out-exercise a bad diet.