Swap Your Fries: New Research Shows How to Reduce Your Type 2 Diabetes Risk

Eating French fries, but not other forms of potatoes, significantly increases your risk of developing type 2 diabetes. A new study from the Harvard T.H. Chan School of Public Health found that how a potato is prepared matters a great deal when it comes to your health.

The study, published in the British Medical Journal, tracked the diets and health outcomes of over 200,000 adults for more than 30 years. Researchers discovered that eating three servings of French fries per week raised the risk of developing type 2 diabetes by 20%. About half of this increased risk was attributed to weight gain over time.

Interestingly, the same association was not found for other preparations of potatoes, such as baked, boiled, or mashed potatoes.

"We're shifting the conversation from, 'Are potatoes good or bad?' to a more nuanced, and useful, question: How are they prepared, and what might we eat instead?" said lead author Seyed Mohammad Mousavi.

What to Eat Instead

The study also highlighted the benefits of swapping out certain foods. Replacing French fries with a healthier option, especially whole grains, was linked to a lower diabetes risk. For example:

• Swapping French fries for whole grains (like whole-grain pasta, farro, or bread) was associated with a 19% lower risk of developing type 2 diabetes.

• Replacing baked, boiled, or mashed potatoes with whole grains could reduce the risk by 4%.

• Even swapping out French fries for legumes, non-starchy vegetables, or refined grains was found to lower the risk.

Conversely, replacing potatoes with white rice was associated with a higher risk of developing type 2 diabetes.

Broader Implications for Health

This research clarifies the connection between potatoes and diabetes, which has been a topic of debate in the past. It suggests that the preparation method of a food can be as important as the food itself.

The findings were consistent across different analyses, including a meta-analysis of data from other studies involving more than 500,000 participants worldwide.

"For policymakers, our findings highlight the need to move beyond broad food categories and pay closer attention to how foods are prepared and what they're replacing," said senior author Walter Willett. "Not all carbs, or even all potatoes, are created equal, and that distinction is crucial when it comes to shaping effective dietary guidelines."

Source: The British Medical Journal | June 4, 2025