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Diet vs. exercise for weight loss

Have you ever heard the phrase“skinny fat”? It’s basically a term that describes people who look thin on the outside yet can’t do one pushup. 

Then there’s the other end of the spectrum — those people who might look a little heavier yet would whoop your butt in an arm wrestle. But if exercise helps you lose weight, why is it that

these people simply can’t seem to lose the pounds? 

To take it one step further, when it comes to weight loss, which is more effective: diet or exercise? 

Diet Wins, According to Research

Researchers from the George Washington University Medical Centre looked at peer-reviewed scientific journals over 25 years to answer the question. They compared weight lost, fat lost, percent body fat decrease, and BMI decrease between those who only changed their diet, those who solely exercised, and those who did both. Here were their results: 

  1. Exercise only simply isn’t as effective for weight loss. 

  • Obese people who changed their diet lost about 24 lbs. by the end of 15 weeks! Those who exercised only lost about 6 lbs. after 20 weeks. In other words, the people who focused on their diet lost FOUR TIMES as much weight.

  • Dieters had a 6% body fat decrease, on average, versus the 3.5% body fat decrease that the exercisers saw. 

2. But exercise is easier to stick with.

  • When they looked at if people had maintained their initial weight loss after a year, those who solely exercised more maintained 70% of their initial weigh loss. 

3. Diet and exercise is still an unbeatable combo. 

  • Not surprisingly, those who dieted and exercised saw more weight loss and fat loss. Interestingly, however, the reduction in BMI they experienced wasn’t much different from those who just dieted. 

But Why?

Many researchers stick to the “calories in, calories out” theory. In other words, if you’re eating more calories than you’re burning, you’re going to gain weight. Take the “Twinkie Diet” that a Kansas State University professor conducted: Though he restricted his calories to less than 1,800 calories per day, he allowed himself to get them from wherever he wanted — from Twinkies, Oreos, or anything he could buy at a convenience store. The result? He lost 27 lbs. in two months. His takeaway: It all comes down to math. 

The other school of thought is that where you get your calories does matter. After all, Twinkies are devoid of any vitamins, minerals, fibre, healthy fats, or real nutrients that our bodies can use to function. So while he lost weight, I’m sure he felt absolutely disgusting.

Nonetheless, here are the main reasons why dieting beat out exercise when it came to weight loss:

  1. You don’t burn as many calories as you think when you exercise. 

  • Ellipticals, treadmills, and other machines at the gym grossly over-estimate the number of calories you burn during your workouts. The truth is, lots of factors affect that number: What was the intensity level? How much muscle do you have? Are you already in shape or just starting out? A machine doesn’t know any of these answers. There’s a complex calculation you can do to find out the exact number of calories you’ve burned, but your best bet is to subtract 30% of the calories from the machine’s final verdict to get a ballpark idea. (So, if the treadmill says you worked off 500 calories, you likely worked off around 350!

2. Working it off takes way, way longer.

  • If there are 3,500 calories in a pound, you have to cut 500 calories per day to lose one pound a week. That’s much easier to do through making simple dietary changes but takes a lot more time when you’re trying to cut those calories through exercise only (see point 1).

  • Two cans of Coca Cola have 280 calories. Think of how much easier it is to just skip the coke rather than workout every time you drink the stuff!

3. Excess calories get stored as fat. Period.

  • Regardless of how much you’re exercising, if you’re constantly consuming too many calories — especially simple sugars — your body has no choice but to store them as fat. And don’t forget, if you’re constantly eating too much, you’re likely not burning through your fat stores during exercise, but rather your glycogen—or stored sugars—in your liver and muscles. 

The Bottom Line

If you want to lose weight, changing your diet is key. That being said, the takeaway of this post is NOT that you should stop exercising. Rather, it’s important to pay attention to eating clean while you’re exercising if you’re trying to lose weight. We also mustn’t forget that weight training especially can greatly assist your weight loss goals since muscle burns far more calories than fat and will increase your metabolism. Finally, there are so many amazing benefits of exercise, including: improving circulation within the body, cleansing your lymphatic system, releasing toxins, and strengthening your bones and muscles. So, really, dieting and exercising will always be an unbeatable combination.

You Tell Me!

Surprised by the research? Let me know in the comments below! 


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