Sticking to low-fat food may sound like the most logical way to drop unwanted pounds, but more and more research suggests that long-term weight loss comes from anything but.
The debate over the effectiveness of low-fat dieting has been going strong ever since it became a craze in the 90s. But an October 2015 review published in The Lancet Diabetes & Endocrinology may finally put a stop to the back and forth.
Researchers from Brigham and Women's Hospital (BWH) and Harvard T.H. Chan School of Public Health (HSPH) gathered data from 53 studies — a total of more than 68,000 people — that compared the long-term effects of low-fat and higher-fat eating plans.
All of the participants managed to keep off an average of just 6 pounds for one year or longer; but people who followed a low-carb lifestyle were about 2.5 pounds lighter than those on the low-fat plans after the one-year mark. Overall, the low-fat diet was unimpressive for long-term weight loss. In fact, the only diet that was less effective than a low-fat diet was when people didn't change eating habits at all.
So the idea that you have to cut fat from your diet in order to lose weight is clearly a myth, according to the researchers.
The Lowdown on Low-Fat Dieting
"It's time for fat to ditch its bad-boy reputation once and for all," says Keri Glassman, RD. "Fat keeps us satisfied and can be helpful in losing weight."
She explains that "clinically meaningful weight loss" traditionally indicates losing 5 percent of your total weight over the course of six months. But one reason why the low-fat diet isn't "meaningful" stems from the fact that it tends to be high in carbohydrates, which can lead to weight gain if consumed in excess. Also, the low-fat versions of desserts and beverages tend to contain low-calorie sugar substitutes, aka artificial sweeteners.
"Those artificial sweeteners are contributing to an increased appetite and cravings," Glassman explains. "They are also messing with your palate by keeping you from being satisfied from naturally sweet foods."
Then you've got the foods that contain "good fats" — monounsaturated fats (olive oil, peanut oil, flaxseed oil, nuts, and avocado) and polyunsaturated fats (safflower oil, sunflower oil, sesame oil, seeds, nuts, and fatty fish) — which (counter intuitively) help melt the fat away.
"It may not make sense to you, but dietary fat actually helps pull stored fat out of your cells to use for energy," Glassman says. "Eating fat boosts metabolic health and helps to break down stored fat to get it out of your system. Say it out loud: 'Fat helps you burn fat!'"