The macronutrient wars
Though all three macronutrients — carbs, protein and fat — are essential to your diet, there’s debate about exactly how much of each you should eat. Should carbs be the star of your diet, and fat be consumed sparingly? Or should fat be fronted-loaded? Or do the relative amounts of macronutrients in your diet even matter at all?
There’s an abundance of advice in books, magazines and online sources about the best way to diet, and there are anecdotes about the diet “trick” that worked miraculously for someone’s mom’s best friend’s former next-door neighbor to be found everywhere. But how do we know if they actually work?
Enter clinical trials, which allow researchers to directly compare the effects of different diets. And even among these trials, some are better designed than others. Researchers consider many factors when looking at the quality of a trial, including the size of the trial (the more participants, the better) and the length of the study period (the longer, the better), when deciding how much stock to put into the results.
The largest clinical trial that compared different diets was the Women’s Health Initiative (WHI) Dietary Modification Trial, which included more than 48,000 postmenopausal women and had a follow-up period of seven years. However, the trial was not designed to look at weight loss. Rather, the goal of the trial was to see how fat in the diet affected the women’s risk of cancer and heart disease. (Because the trial was only in women, it’s unclear if the results also apply to men.)