A Weekly French Fry Habit May Increase Diabetes Risk

French fries—golden, crispy, and savory—are irresistible. For many, they're a comfort food, but a new study reveals a surprising health consequence: People who eat French fries three times a week have approximately a 20% higher risk of developing type 2 diabetes compared to those who eat them less than once a week.

The findings stem from a nearly 40-year follow-up of over 205,000 adults in the United States who did not have heart disease, cancer, or diabetes at the start.

French fries are classified as an ultra-processed food—widely linked to obesity, metabolic disorders, and chronic disease. Frying introduces harmful fats, reduces nutritional content, and may promote insulin resistance and inflammation. Processing (peeling, frying, adding sugar/salt) enhances flavor but harms health.

However, potatoes themselves aren't inherently bad—when prepared properly (e.g., with the skin on, baked, or boiled), they are rich in fiber, potassium, vitamin C, and resistant starch.

French Fries vs. Other Potatoes: Cooking Method Matters

Research shows that boiling, baking, or mashing potatoes doesn't significantly affect diabetes risk as frying them. Frying significantly alters metabolic effects. Deep-frying fries, high in calories, absorbs oil, and salt, increasing their caloric density and rapidly raising blood sugar. Ultra-processing adds refined oils, additives, and preservatives, while removing fiber. All of these factors can disrupt metabolic and gut health.

What happens if you switch things up?

Researchers also explored what happens when you replace French fries with whole grains (such as quinoa, whole-wheat pasta, or bread). The results? Replacing French fries with whole grains reduced the risk of diabetes by 19%.

Replacing any type of potato (even cooked or mashed neutral potatoes) with whole grains still had benefits—a reduction of approximately 4-8% in diabetes risk.

At the same time, the analysis showed that replacing potatoes (especially French fries) with white rice actually increased the risk of diabetes—a reminder that not all substitutions are ideal.

While these findings may be concerning, they also offer a path forward. Moderation is key. Enjoying French fries occasionally, rather than making them a regular part of your diet, can mitigate the associated health risks. Furthermore, adopting healthier cooking methods, such as baking, boiling, or air-frying, can preserve the nutritional value of potatoes while reducing their harmful effects.

While people's love for French fries is understandable, it's important to be aware of the health implications of frequent consumption. By choosing cooking methods wisely and considering healthier alternatives, people can enjoy their favorite foods without compromising their health. As this study demonstrates, small changes in dietary habits can significantly improve long-term health, including reducing the risk of type 2 diabetes.