Stanforth explained that exercise actually burns less calories than people think. It also requires consistent effort, meaning it takes much longer to see results than simply fixing your diet.
"You'd have to walk 35 miles to burn 3,500 calories. That's a lot of walking. But if you look at eating, a Snickers bar might have, say, 500 calories. It's going to be a lot easier to cut the Snickers bar than to do 5 miles of walking every day," he explained, (note that a normal Snickers bar is actually about 220 calories, while a Snickers '2-to-go' is 440).
Shawn M. Talbott, PhD, nutritional biochemist and former director of the University of Utah Nutrition Clinic, voiced a similar expert opinion. However, he also suggested a combination of diet and exercise is the ideal weight loss solution.
"As a rule of thumb, weight loss is generally 75 percent diet and 25 percent exercise. An analysis of more than 700 weight loss studies found that people see the biggest short-term results when they eat smart," Talbott explained to the Huffington Post. "On average, people who dieted without exercising for 15 weeks lost 23 pounds; the exercisers lost only six over about 21 weeks. It's much easier to cut calories than to burn them off. For example, if you eat a fast-food steak quesadilla, which can pack 500-plus calories, you need to run more than four miles to 'undo' it!"