Low-Carb or Low-Fat: Which Diet Is Better for Weight Loss?
We asked our nutritionist to weigh in.
From Paleo to Keto to personalized nutrition plans determined by your DNA, today’s weight loss market is flooded with all sorts of low-carb, low-fat, and calorie-restricted options. When it comes to choosing an actual plan, it’s not easy to know which one is right for you.
A recent study published in the Journal of the American Medical Association, suggests that there may be a much simpler (and far less restrictive) solution for losing weight. The study, conducted by the Stanford University School of Medicine, suggests that losing weight isn’t necessarily about the type of diet you’re following or your genetic makeup, but rather about your overall diet quality.
To conduct the study, researchers randomly divided 609 participants into two diet groups—low-fat or low-carbohydrate. Before they began, all participants took a DNA test and insulin test to surface factors—such as genetics or insulin levels—that could determine whether your body performs better on a low-carb or low-fat diet. Bearing these results in mind, half the participants followed a healthy low-carb diet while the other half followed a healthy low-fat diet for one year.
While each diet consisted of different types of foods, both emphasized whole, unprocessed foods. Throughout the study, participants also regularly attended health sessions led by dietitians that focused on long-term weight loss strategies—such as avoiding highly-processed foods and added sugars, as well as shopping at the farmer’s market.
“We wanted [participants] to choose a low-fat or low-carb diet plan that they could potentially follow forever, rather than a diet that they’d drop when the study ended,” said Dr. Christopher Gardner, study leader and Director of Nutrition Studies at the Stanford Prevention Research Center, in a press release from Stanford Medicine.
After a year, researchers found no difference in weight loss between the healthy low-carb group and the healthy low-fat group. Both groups lost relatively equal amounts of weight—about 13 pounds—regardless of the type of diet they followed.
Here’s what surprised researchers even more—the results of their DNA and insulin tests did not appear to affect participants’ ability to lose weight.
“On both sides, we heard from people who had lost the most weight that we had helped them change their relationship to food, and that now they were more thoughtful about how they ate,” Gardner stated in the press release.
While the results of Gardner’s study are encouraging, Cooking Light Assistant Nutrition Editor Jaime Vespa, MS RD, believes more research is needed to confirm its actual validity. “I don't think you can draw specific conclusions about the effects of low-carb versus low-fat dieting if you’re relying solely on participant reporting and not taking into account other external factors.”
However, what Vespa does like is the study’s strong focus on diet quality. She said, “I can appreciate the fact that they didn’t place a huge emphasis on calorie counting and instead focused on a real and wholesome foods approach to help the participants improve their relationship with food and to eat more mindfully.”
So while we may not have enough information yet to prove whether low-carb or low-fat is healthier, here’s what we do know: adopting healthier eating practices like filling your plate with fruits and vegetables, choosing whole grains, and limiting added sugar, is a smart and reliable way to lose weight—and keep it off for good.