Fry Consumption Linked to 20% Type 2 Diabetes Spike

New study reveals cooking method, not potato itself, is key

Eating french fries three times a week may significantly increase your risk of developing type 2 diabetes, a large-scale study suggests. Researchers found a 20 percent rise in diabetes among those with this frequent fry habit.

Cooking Methods Alter Risk

The extensive analysis, tracking over 205,000 U.S. adults for nearly four decades, highlighted that the method of potato preparation is the critical factor. Interestingly, consuming baked, boiled, or mashed potatoes in similar quantities showed no meaningful change in diabetes rates.

Lead author **Seyed Mohammad Mousavi** from the Harvard T.H. Chan School of Public Health explained that boiling or baking potatoes maintains their tuber structure. This preservation means more starch resists rapid digestion, leading to steadier blood sugar levels.

Conversely, deep frying breaks down starch granules and incorporates fat. This process elevates the food’s glycemic index, which measures how quickly a food impacts blood sugar. A higher index can demand more insulin, potentially straining the body’s metabolic system over time.

Whole Grains Offer Protection

Swapping potato dishes for whole grains three times weekly could trim diabetes risk by up to 8 percent. This protective effect jumped to 19 percent when the substitution specifically targeted french fries. Whole grains, rich in fiber, magnesium, and phytochemicals, help blunt glucose spikes and may improve insulin sensitivity.

Refined Starches, Including White Rice, Raise Concerns

The study also found that substituting white rice for potatoes showed a slight increase in diabetes odds. White rice, stripped of its bran and germ during milling, is largely pure starch that digests quickly, mirroring the high glycemic index of fries. While brown rice performed better, whole grain wheat products emerged as the most beneficial alternative.

A 2023 report indicated that over 37 million Americans live with diabetes, underscoring the importance of dietary choices in managing the disease (CDC).

Frying Creates Harmful Compounds

Deep-fried potatoes often come with added salt, batter, and are cooked in repeatedly heated oils. These conditions can create compounds that may be detrimental to pancreatic cells. Portion size also plays a significant role, with restaurant servings frequently exceeding the study’s baseline of one cup.

Walter Willett, professor of epidemiology and nutrition, advised, “Small changes in our daily diet can have an important impact on risk of type 2 diabetes.” He suggested replacing fries with a salad or whole grain roll as a healthier alternative.

Healthier Fry Habits Recommended

Experts suggest that if you opt for fries, choose potatoes with skins intact, moderate added fat, and pair them with vegetables or protein to slow digestion. Cold potato salad made from boiled potatoes can offer resistant starch, further moderating post-meal glucose levels.

You don’t necessarily need to eliminate fries entirely. Reducing frequency and portion size can lower your risk. Consider alternatives like barley, quinoa, or air-fried potato wedges for a flavorful yet healthier meal choice.

The comprehensive findings were published in the journal *The BMJ*.