- Eating French fries three or more times a week is linked to a 20% higher risk of developing type 2 diabetes.
- Experts say the way fries are processed and cooked, including added sugars, refined oils, and high heat, plays a major role in raising the risk.
- Fries are considered an ultra-processed food that may impact blood sugar, gut health, and inflammation when eaten regularly.
- An occasional serving of fries is unlikely to cause harm, but it’s recommended to limit intake and focus on balanced, whole-food meals to support metabolic health.
Love a side of fries? New research cautions that moderation is key.
Eating fried potato products like French fries three times weekly is linked to a higher risk of developing type 2 diabetes (T2D).
Researchers followed over 150,000 participants over several decades and found that those who ate fried potatoes frequently were more likely to develop T2D compared to those who ate them less often.
The study, published on August 6 in
Experts say the findings highlight well-established concerns over ultra-processed food consumption and the role these foods play in blood sugar regulation and long-term health.
“French fries are a form of ultra-processed food high in refined carbohydrates, fat (often from unhealthy oils due to the re-heating and reuse of them), and calories,” she told Healthline.
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While potatoes are naturally rich in fiber, potassium, and vitamins C and B6, it’s how they are prepared that matters.
“Frying potatoes increases their energy density (calories per gram) and often introduces harmful compounds like trans fats or advanced glycation end products, especially when oils are reused,” said Ludlam-Raine.
“Frying also breaks down some of the natural fiber and increases the glycemic response.”
Caroline Roberts, a nutritional therapist at Integral Wellness, explained that industrially prepared fries go through multiple steps that can raise their glycemic index. Roberts wasn’t involved in the new study.
“For the big chain fast food restaurants and any frozen French fries you buy in the supermarket, the skin of the potato is removed, removing most of the fiber content and immediately raising the glycemic index,” she told Healthline.
“Once cut and washed, sugar is added as part of the preparation process before they are cooked, which ensures they have the golden brown colour we all know, but raises the glycemic index of the fries further.”
Roberts added that the part-boiling and part-frying process increases fat content and gelatinizes starch, which may cause a rapid rise in blood glucose levels.
Then there are the extra ingredients to consider.
“Ultra-processed foods like French fries often contain additives, preservatives, emulsifiers, and refined oils that aren’t typically used in home cooking,” Ludlam-Raine noted.
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- cardiovascular disease
- obesity
- mental health conditions
- premature death
Some good news? If you enjoy French fries, you don’t have to swear off them forever.
“Overall dietary pattern is crucial when assessing diabetes risk,” Roberts said.
A healthy diet that emphasizes whole foods with adequate protein, fiber, and healthy fats can help minimize the risk of type 2 diabetes. Therefore, Roberts noted, the occasional serving of fries can be enjoyed as part of a balanced diet.
Ludlam-Raine agreed that French fries should be consumed in moderation rather than regularly.
“While an occasional portion isn’t likely to cause harm, habitual intake matters,” she said. “I’d recommend limiting fries and similar foods to no more than once every couple of weeks and ensuring meals are balanced to help stabilize blood sugar.”
Like other ultra-processed foods, however, French fries are designed to be highly palatable, which may trigger cravings and lead to overconsumption and raise blood sugar levels, Roberts noted.
The new research also flagged white rice as a potential contributor to type 2 diabetes. Like French fries, white rice can be digested quickly and cause blood sugar spikes.
“White rice has been stripped of its fibrous outer layer,” said Roberts. “Without fiber, white rice is rapidly digested and can raise blood sugars significantly in some people.”
Ludlam-Raine explained that “refined carbohydrates are quickly broken down into glucose, causing rapid rises in blood sugar and insulin levels. These foods lack the fiber, vitamins, and minerals found in whole grains, which help slow digestion and support metabolic health.”
This doesn’t mean white rice is off the menu entirely. Pairing it with protein and healthy fats can prevent rapid blood sugar spikes.
If you’re looking for an alternative, experts recommend simple swaps, like brown rice, bulgur, or quinoa.
If you’re worried about your type 2 diabetes risk or you’re looking to reduce your intake of French fries, there are lots of ways you can make healthier choices.
If you want to make something similar to French fries at home, Roberts advised cutting white potatoes into wedges, keeping the skin on to retain the fiber content, and using an air fryer to cook them so that no oil is needed.
“Cooked and reheated white potatoes have a much lower glycemic index because the process of cooling and reheating them activates their resistant starch content,” she explained.
Ludlam-Raine recommended “homemade oven-baked potato or sweet potato wedges using olive oil and herbs” as an easy alternative.
It’s what you eat day to day that truly matters most.
Both experts stressed the importance of building meals with blood sugar balance in mind: focus on whole food protein sources, fiber-rich vegetables, and healthy fats.
To help lower your risk of type 2 diabetes, Ludlam-Raine offered a few nutrition tips:
- Include fiber at every meal from vegetables, whole grains, pulses, nuts, and seeds.
- Prioritize protein, like eggs, fish, tofu, or beans.
- Choose healthy fats, such as olive oil, avocado, and oily fish.
- Limit less nutritious ultra-processed foods and sugary drinks.
Ultimately, most experts agree it’s the overall pattern of what you eat that matters most.
“Making small, sustainable swaps, like choosing whole grains over refined carbs and preparing meals at home more often, can significantly reduce long-term risk,” said Ludlam-Raine.
