A new long-term study published in The BMJ links frequent consumption of french fries links to increased risk of Type 2 diabetes, raising concerns among healthcare professionals about dietary habits.
Frying Methods May Influence Type 2 Diabetes Risk, Harvard Study Finds
A new study conducted by researchers at the Harvard T.H. Chan School of Public Health has identified a clear association between the regular consumption of french fries and an elevated risk of developing Type 2 diabetes. The findings, published Wednesday in The BMJ, underscore the role that food preparation methods play in chronic disease prevention.
The research analyzed the dietary patterns of more than 205,000 U.S. adults over nearly four decades, tracking the onset of Type 2 diabetes. Participants who consumed three or more servings of french fries per week faced a 20% higher risk of developing the condition, compared to those who ate potatoes prepared by boiling, baking, or mashing.
Preparation Method Determines Nutritional Impact
Lead author Dr. Seyed Mohammad Mousavi, a postdoctoral research fellow at Harvard, noted that the preparation method—particularly deep frying—was a significant contributor to the increased diabetes risk. Unlike boiled or baked potatoes, french fries are typically cooked in oils rich in saturated and trans fats, both of which are known to contribute to insulin resistance, obesity, and systemic inflammation.
“Even a small amount of french fries, less than one serving per week, showed a statistically significant association with increased diabetes risk,” said Dr. Mousavi.
Health professionals emphasize that the energy density of fried foods—calories derived from fat absorption during cooking—can predispose individuals to weight gain, a major risk factor for diabetes.
Dr. Candida Rebello, director of the Nutrition and Chronic Disease program at Louisiana State University, who was not involved in the study, said the findings are consistent with broader evidence linking fried food intake to metabolic disorders.
Implications for Preventive Care and Dietary Guidance
The study is particularly relevant for healthcare providers offering dietary counseling for at-risk populations. With over 37 million Americans currently living with diabetes—most with Type 2—the research reinforces the need for personalized nutrition advice that considers not only what patients eat, but how those foods are prepared.
While potatoes themselves offer health benefits such as potassium and dietary fiber—especially when consumed with the skin—nutritional experts caution against high-fat toppings like butter, cheese, and bacon that often accompany non-fried versions.
Dr. Shannon Galyean, assistant professor of nutritional sciences at Texas Tech University, said, “Potatoes can be part of a healthy diet, but how they are prepared and what is added matters significantly for blood sugar control.”
Recommendations for Healthier Alternatives
For patients looking to reduce their diabetes risk, experts recommend:
- Baking or boiling potatoes instead of deep frying.
- Using healthy oils like olive or avocado oil if frying at home.
- Choosing whole grains (e.g., quinoa, brown rice, farro) over starchy sides, which have a lower glycemic index.
- Maintaining a balanced, colorful diet rich in vegetables, lean protein, and whole foods.
Dr. Mousavi noted that whole grains were associated with a lower diabetes risk than any form of potato, while white rice showed a stronger link to diabetes than potatoes.
Although moderation remains a key tenet of most dietary habits., the findings may influence clinical discussions about meal planning, especially for patients with prediabetes or those with a family history of metabolic diseases.
Healthcare professionals are encouraged to integrate findings like these into routine counselling to support early intervention and long-term chronic disease prevention.
