The American Heart Association (AHA) has published a report analyzing popular diets to identify the best and worst for heart health. The purpose of the report is to provide an evidence-based counterpoint to misinformation promoted on social media about nutrition by diet books, blogs, and influencers. The team of nutrition scientists, cardiologists, dietitians, and other health experts evaluated dietary patterns to see how closely they aligned with the AHA’s guidelines for heart-healthy eating based on evidence from randomized controlled trials, epidemiological research, and other studies. The guidelines recommend eating a wide variety of fruits and vegetables, whole grains, lean cuts of meat, foods like olive oil, vegetable oils, and seafood, and limiting foods that are salty, sugary, highly processed, or made with white flour and other refined grains. Alcohol should be consumed in moderation or not at all, and people should limit intake.
The report gives the lowest rankings to some of the buzziest diets widely promoted on social media, such as very-low-carb regimens like the Atkins and ketogenic diets and the paleo diet. These diets typically require restricting carbohydrate intake to less than 10% of daily calories and are widely promoted for weight loss and endorsed by celebrities. The report notes that these diets do have some beneficial features, like restricting sugar and refined grains, and they encourage the consumption of non-starchy vegetables, but they generally require limiting many healthy carbs that align with the AHA’s dietary principles.
Additionally, they typically include a high intake of fatty meats and foods rich in saturated fat. While some studies have found that very-low-carb diets can help with weight loss and improve certain markers of metabolic health, the AHA’s report notes that these improvements tend to be short-lasting and that very-low-carb diets often cause an increase in LDL cholesterol levels, which can heighten the risk of heart disease.
The paleo diet is also problematic, as it excludes grains, vegetable oils, most dairy products, and legumes such as peanuts and soybeans. The theory behind the diet is that it allows foods like fruit and honey that our hunter-gatherer ancestors had access to but excludes grains and other foods associated with modern agriculture. These diets have also been criticized for promoting an all-you-can-eat stance toward red meat, from steaks and burgers to bacon and processed deli meats. The report’s low ranking for the ketogenic and paleo diets is expected to generate controversy. In 2019, three doctors published an essay in JAMA Internal Medicine cautioning that the enthusiasm for the ketogenic diet was outpacing the science.
The report’s authors hope that it will provide clarity for people who are confused about heart-healthy eating and feel they don’t have the training or time to evaluate the important features of the different diets. It is also important to note that these guidelines are just one piece of the puzzle for optimal health, and other factors, such as genetics and exercise, also play a role. Nonetheless, the AHA’s report provides an evidence-based framework for evaluating different diets and identifying those that are most likely to promote heart health.