What 200,000 People Taught Us About Eating for a Healthy Heart

Low Carb Vs. Low Fat: It’s easy to forget that low-fat diets were once the reigning wisdom before low-carb took over and dominated the weight loss and heart health conversation for the better part of two decades. But a major new study suggests the whole framing may be beside the point.

The Study: Harvard researchers tracked nearly 200,000 adults for over 30 years and documented more than 20,000 cases of coronary heart disease. They found that both low-carb and low-fat diets were linked to lower heart disease risk, but only when people prioritized nutrient-dense whole foods and healthy fats. Versions heavy in refined carbs and animal-based fats increased risk regardless of which dietary camp people belonged to.

The Takeaway: It’s not really about how many carbs or how much fat you’re eating. What matters is the quality of what’s on your plate. Think whole, minimally processed foods over anything that sits on a shelf and comes in a package.

Keep in Mind: Study participants were health professionals with better-than-average health awareness and access to care, so these findings may not translate perfectly to the general population.