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Maybe you’re someone who runs 20 to 30 miles a week but regularly gets fast food for dinner. Perhaps you track what you eat Monday through Friday but binge on the weekends. Or maybe you’re someone whose kitchen is stocked with chips, cookies and soda because your workout keeps you thin.
The idea of eating anything you want without consequences might sound like a dream — especially if you’ve convinced yourself that you’re going to burn it off in your next cardio session. But the reality is that it doesn’t matter whether you work out longer or at a higher intensity, experts say. Exercise cannot completely reverse the effects of a bad diet.
You can look thin and still be unhealthy
“Skinny fat” is the unofficial term used on social media to describe a person who looks slim but has a high percentage of body fat. A regular gymgoer could have little subcutaneous fat — the fat right under your skin that’s easy to pinch — but lots of visceral fat. This fat layer is less noticeable because it wraps around your organs.
Visceral fat is dangerous than the outer layer of fat you see, warned Dr. Colin Carriker, an exercise physiologist and associate professor of health and human performance at High Point University in North Carolina. A buildup of visceral fat from eating processed foods high in sugar, salt and carbs could lead to the same type of risks as a person with obesity.
For example, large amounts of visceral fat circulating throughout the body could cause the arteries to harden and become narrower, a disease known as atherosclerosis. This blockage stops blood from flowing to the rest of the body’s tissues and increases the risk for a heart attack and stroke.
There’s also an increased risk for premature death if you exercise but neglect healthy eating. In one of the largest studies to look at the effects of physical activity and diet quality, researchers found those who regularly exercised but ate anything they wanted were at greater risk of mortality compared with people who both exercised and made healthy dietary choices.
Why it’s virtually impossible to outrun a bad diet
If you’re looking to lose weight, the key is to develop a caloric deficit in which you burn calories more than what you are consuming. But eating high-calorie fatty foods regularly can make this a challenge. “You’re overconsuming calories and will have to do way more exercise than a person can sustain on a long-term basis,” Carriker said.
One idea would be to spend more time exercising or engaging in a more intense workout. But this plan doesn’t really work when you’re running on fumes, said Grace Derocha, a registered dietitian and spokesperson for the Academy of Nutrition and Dietetics. That’s because junk food and sugary beverages are filled with empty calories.