It's the annual concerted promise Americans make —vowing to shed some pounds.
If you're one of the many who are trying to lose weight, but struggling, you're probably wondering how you can best do so with the minimum effort. Exercising for hours per day may not sound ideal, or even practical.
Well, according to doctors and leading weight-loss experts, more exercise isn't actually the quickest or most efficient way to reach your ideal waist line.
"Studies tend to show that in terms of weight loss, diet plays a much bigger role than exercise," Philip Stanforth, a professor of exercise science at the University of Texas and the executive director of the Fitness Institute of Texas, told Business Insider.
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!"
"When you neglect your nutrition you neglect your workout," Slater said. "The best remedy is to eat healthier."
And the scientific evidence is there to back the expert advice.
A review of 20 different studies published in the "American Journal of Clinical Nutrition" in 2014, which overall looked at the diets of some 3,000 individuals, revealed that high-protein diets and low-calorie meal replacements helped people keep weight off better than exercise.
Another 2011 review examined the relationship between fat mass and physical activity in children. The results showed that less physical activity is not the principle factor driving unhealthy weight among kids.
At the same time, while removing calories from your diet may have the quickest impact on your waistline, experts caution that exercise is important as well.
"A combination of diet and exercise is best at any stage of weight loss," Albert Matheny, R.D., C.S.C.S., co-founder of SoHo Strength Lab and PROMIX Nutrition told Women's Health. "Exercise should be a mix of strength training and cardiovascular training, not just cardio. Both modes of exercise burn calories and, in turn, lead to stored fat being used as a source of energy."
Michele Olson, PhD, professor of physical education and exercise science at Auburn University at Montgomery, Alabama told Huffington Post that is an important component to weight loss.
"Without [exercise], only a portion of your weight loss is from fat — you're also stripping away muscle and bone density. Since working out stimulates growth of those metabolic tissues, losing weight through exercise means you're burning mostly fat," Olson explained. "The number on the scale may not sound as impressive, but because muscle takes up less space than fat does, you look smaller and your clothes fit better."
As you work toward your weight loss goal, cutting calories will show you the quickest results. But for the best results, increase your physical activity as well.