French Fries Linked to Higher Type 2 Diabetes Risk, Study Finds

A major new study has linked frequent French fry consumption to an increased risk of type 2 diabetes – but also found that how you cook your potatoes makes a big difference.

The research followed 205,107 U.S. healthcare professionals over nearly 40 years, recording 22,299 cases of type 2 diabetes. After adjusting for other health and lifestyle factors, researchers discovered a clear pattern: fried potatoes, especially French fries, were associated with higher diabetes risk, while boiled, baked, or mashed potatoes were not.

French Fries and Diabetes Risk

Eating three servings of fries per week was linked to a 20% higher risk of developing type 2 diabetes. However, replacing those fries with whole grains could reduce the risk by 19%.

The data came from two meta-analyses involving over 500,000 participants worldwide. The results also revealed that replacing potatoes with certain refined grains, like white rice, could actually raise diabetes risk.

As lead researcher Prof. Walter Willett explained:

“Not all carbs – or even all potatoes – are created equal. Preparation methods matter, and small dietary changes can significantly impact diabetes risk.”

Expert Reactions

While the findings might disappoint French fry lovers, nutrition experts stress that potatoes themselves are not inherently unhealthy. Instead, it’s the frying process that appears to increase the health risk.

Daniel B. Ibsen and Yanbo Zhang, in an accompanying editorial, noted that potatoes remain an environmentally sustainable crop, and shouldn’t be eliminated from diets entirely.

However, Dr. Ruth Boocock from Teeside University cautioned that the study is observational, meaning it can’t prove cause and effect. The participants—mostly white healthcare workers—may not represent the broader population.

Cristóbal Morales, an endocrinologist at Vithas Sevilla Hospital, added:

“The research supports existing recommendations: prioritize whole grains and limit fried foods.”

The Takeaway

• Limit fried potato consumption, especially French fries.

• Prefer boiled, baked, or mashed potatoes when including them in your diet.

• Swap fries for whole grains to lower diabetes risk.

• Remember: preparation method matters more than the potato itself.

As co-author Seyed Mohammad Mousavi put it:

“We’re moving from asking if potatoes are good or bad to asking how they’re prepared and what we might eat instead.”

The study is published in The BMJ.