Low-Carb vs Low-Fat? The Key to Heart Health Is Food Quality

Should you have a low-fat diet or a low-carb diet? Most people believe that a diet having low fats and low carbohydrates is healthy. However, a new study suggests focusing on the quantity of nutrients like carbohydrates, fats or protein may not be the best way to improve your heart health, the importance should be paid to the quality of food.

The Study Findings

Researchers at the Harvard TH Chan School of Public Health studied the food intake of nearly 200,000 people for more than 30 years to see the impact of that intake on the health of the participants.

Their findings, published in February 2026 found that both low-carb and low-fat diets can reduce the risk of coronary heart disease in individuals, but only if the foods chosen to implement those diets are the right ones.¹

"Our findings help debunk the myth that simply modulating carbohydrate or fat intake is inherently beneficial," said lead author Zhiyuan Wu, a postdoctoral research fellow at Harvard. "The quality of foods is what's most important to protect heart health."

The participants were divided into three categories: Those who were on a healthy low-carb diet and others on healthy low-fat diet and the third category had people on unhealthy versions of the same diets.

Those on a healthy low-carb diet, which included vegetables, whole grains, nuts, legumes, olive oil etc. were 15% less likely to get coronary heart disease.

And people on a healthy version of the low-fat diet, which included fruits, whole grains, plant-based proteins were 13% less likely to get coronary heart disease.

However, those on unhealthy versions of the same diet, loaded with refined carbohydrates, processed foods, animal fats, were at higher risk of heart disease.

Simply put, an avocado and a bag of chips may both be low-fat, but the former is good for the heart and the latter is certainly not.

What Makes a Diet High Quality?

Foods that are high quality and good for heart health include:
-Whole grains such as oats, brown rice, and whole wheat.
-Fruits and vegetables - the more colorful, the better.
-Legumes such as dal, rajma, chickpeas, and lentils.
-Nuts and seeds.
-Healthy fats such as olive oil and avocados.

The food groups that were linked to heart disease risk included refined carbs such as white bread, maida, and sugary drinks, as well as processed meats and saturated animal fats.

Why Should This Matter to You?

The fact is that heart disease is the biggest cause of death in the world, and diet is one of the most controllable factors. However, people usually end up getting caught up in macro counts, worrying about how much carbs or fat is in their food and completely neglecting the fact about the type of carbs or fat.

Irrespective of a diet being lower in carbohydrates or fats, a diet that emphasizes plant-based foods, healthy fats, and whole grains is associated with improved cardiovascular outcomes.

You don't have to choose between low-carb and low-fat to keep your heart healthy. But choose real whole foods, no matter what diet category you fall into.

Stop obsessing over macros and look at what you're really eating - more dal and less maida. More fruits and fewer biscuits. More olive oil and less butter.

References

1. JAMA Network |Low-Carb vs Low-Fat Debate

Disclaimer: This content is for general informational purposes only and should not replace professional medical advice. Always consult a qualified healthcare provider with any questions about your health or treatment options.