Turns out, eating foods with fat — everything from avocados and nuts to dairy fat — doesn't make us fat. A new study published in the Annals of Internal Medicine adds to the body of evidence that cutting back on carbs, not fat, can lead to more weight loss. The low-carb group, which reduced their carb consumption to about 28 percent of their daily calories, lost almost three times as much weight as the low-fat dieters who got about 40 to 45 percent of their calories from carbs. The low-fat group lost about 4 pounds, whereas the low-carb group's average weight loss was almost 12 pounds. All participants attended regular meetings where they learned about portion control, healthy eating and overall nutrition. The makeup of the low-carb group's diet was: 28 percent carbs 40 to 43 percent fat (twice as much poly and monounsaturated compared to saturated) about 28 percent protein The makeup of the low-fat group's diet was: 28 percent fat 40 to 45 percent carbs 28 to 32 percent protein 
 
 Lydia Bazzano, one of the study authors and an associate professor of epidemiology at Tulane, says she had anticipated some difference in weight loss between the two groups. Bazzano agreed that the overall diets improved among the participants and they were encouraged to eat healthier forms of protein like chicken, fish, nuts and beans. Those in the low-fat group were told not to get more than 30 percent of their daily energy from fat and no more than 55 percent of their daily energy from carbohydrates. It's not just waistlines that respond. She also said her team is not sure why people on the low-carbohydrate diets lost more weight and had lower risk factors for heart disease after one year. One big study published in the New England Journal of Medicine found that a Mediterranean diet rich in olive oil cut the risk of heart attacks and strokes by 30 percent, compared to a low-fat diet. "Too much refined carbohydrates — white bread, white rice, potato products — all the foods that crept into our diets as we've followed the low-fat craze has undermined our metabolism," says Ludwig.
– If you're trying to lose weight on a low-fat diet and it's not working, here's why. Refined carbohydrates—found in processed foods like white breads, white rice, and pastas—tend to be loaded with sugar, which messes with our metabolisms, making it harder to burn calories. Eating nearly half your calories via healthy fats, on the other hand—think salmon, avocados, nuts, and vegetable oils—has been shown in a recent study to result in twice as much weight loss as seen in those assigned to low-fat diets. "It's a double-whammy for weight gain," one researcher tells NPR. "We've been told for decades that if you don't want fat on your body, don't put fat into your body. It's a very appealing notion, but the problem is it's wrong." What's more, the researchers say there was no increase in total or bad cholesterol between the groups, which has been feared would be the case in higher-fat diets, reports Reuters. It remains unclear precisely why people on lower-carb diets not only lost more weight but had lower heart disease risk factors. It's something the researchers say will need to be studied more and for longer than the one-year period of this investigation. (Welcome back, butter—even saturated fats might not be as bad as once thought.)