The study followed 73 participants on a low-fat diet and 75 on a low-carb diet for 12 months. The low-carb dieters were instructed to keep below 40 grams of digestible carbs per day (total carbs minus total fiber). Even though the study didn't specifically differentiate between more- and less-refined carbs, those that are less-processed tend to have more fiber in them. So, they account for fewer of those precious digestible carbs. As for the the low-fat dieters, they were told to get less than 30% of their energy intake each day from fats. But, there were no specific calorie or energy goals in either diet.
Not only did those in the low-carb group lose more weight, they also had significantly lower scores on the Framingham measure, an assessment of risk for having a heart attack in the next 10 years based on cholesterol levels, blood pressure, and smoking habits. So, even if you're not trying to lose weight, cutting out the carbs could still be beneficial.
One common criticism of low-carb diets is that eating large amounts of protein instead might have unintended health effects, including increased risk for cardiovascular disease. The American Heart Association doesn't recommend high-protein diets for losing weight. And, previous studies of low-carb diets' effects on heart disease showed conflicting results.
But, this study is a long-term assessment and includes a pretty diverse sample of participants, compared to other research (51% of participants were Black and 88% were female). So...darn. It looks like we might see yet another resurgence of the low-carb diet. Fare thee well, cronut. Hopefully, we'll see you a-grain. Pasta la vista.