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Posted on 08/13/2025 7:42:00 PM PDT by SeekAndFind
Potatoes have long had a bad rap for being high in carbs. A new study backs that concern—at least in part.
That weekly french fry habit could be setting you up for diabetes decades down the road. Research found that eating french fries just three times a week may significantly raise Type 2 diabetes (T2D) risk—but, surprisingly, other potato preparations showed no increased risk at all.
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“Our findings suggest it’s not fair to put all potatoes in the same basket,” lead author Seyed Mohammad Mousavi told The Epoch Times.
The study, led by Harvard T.H. Chan School of Public Health, tracked more than 205,000 adults across three major U.S. observational health studies for 30 years. Participants regularly reported what they ate, along with details about their health and lifestyle.
The study found that every three extra servings of potatoes per week was associated with a 5 percent increase in T2D risk. For french fries, that jump was even higher—20 percent per three servings.
In contrast, eating baked, boiled, or mashed potatoes was not associated with an increased risk, suggesting that french fries are the main driver behind the link between potatoes and diabetes.
French fries are often loaded with salt, which can raise blood pressure and trigger inflammation, increasing the risk of T2D. However, it’s more than just the fat and salt content driving the diabetes risk.
“French fries are typically deep-fried at very high temperatures, which can produce harmful compounds,” Mousavi said. One such compound is acrylamide, formed during browning and linked to inflammation, insulin resistance, and blood vessel damage.
“Due to their deep-fried nature, they [fries] are also much higher in calories than baked or mashed potatoes,” said Melissa Mitri, a registered dietitian-nutritionist and owner of Melissa Mitri Nutrition, who was not involved in the study.
The large amounts of oil used in frying also introduce trans fats, which further increase insulin resistance and inflammation. Combined with the high-temperature cooking that breaks down resistant starches, french fries become a perfect storm for blood sugar chaos.
Even outside of french fries, people who ate seven or more servings of potatoes per week had a 12 percent higher risk of developing T2D. The risk rose with greater intake.
While preparation plays a key role in how potatoes affect diabetes risk, it’s worth noting they still have a high glycemic index, meaning they can rapidly raise blood sugar.
Potatoes are a common source of carbohydrates, especially starch, which the body quickly breaks down into sugar. Because of this, eating potatoes can cause a sharp rise in blood sugar levels soon after a meal.
Frequent blood sugar spikes force the pancreas to release more insulin repeatedly. Over time, this constant demand can cause insulin-producing cells to wear out or stop working properly. This contributes to insulin resistance and reduced insulin production—both key drivers of T2D.
A potato’s glycemic index, which ranks how quickly and how much foods raise blood sugar levels after eating, depends on how they’re prepared. A higher glycemic diet is associated with an increased risk of developing T2D because the foods cause a rapid and significant rise in glucose levels.
Mashed and boiled potatoes have higher glycemic indexes because cooking breaks down their structure and makes the starch easier to digest, leading to faster spikes in blood sugar.
Deep frying also softens the starch inside, but the hot oil forms a crust with some resistant starch that slows digestion. The fat in fries also helps slow down how quickly sugar is absorbed, making their glycemic index a bit lower than mashed or instant potatoes.
Using different food preparation methods can reduce potatoes’ risks:
Replacing potatoes with other carbohydrates reduced T2D risk. Swapping mashed, boiled, or baked potatoes for whole grains like pasta, bread, or farro lowered diabetes risk by 4 percent, while replacing french fries cut it by 19 percent. Substituting fries with whole grains, legumes, brown rice, or vegetables also reduced risk by 19 percent.
The only swap that increased risk was white rice, which was linked to a 3 percent higher risk of T2D. This may be because white rice has a high glycemic index. “White rice is stripped of fiber and nutrients, digests quickly, and causes sharper spikes in blood sugar,” Mousavi said.
Whole grains have fiber that slows digestion and causes smaller blood sugar spikes.
Perhaps most concerning, the study found that potato intake 12 to 20 years before diagnosis had the strongest association with diabetes risk—suggesting dietary choices in your 20s and 30s could determine your health in your 50s and 60s.
Type 2 diabetes develops gradually, with insulin resistance and inflammation starting decades before symptoms appear.
Even after adjusting for genetics, diet, and lifestyle, the link between french fries and diabetes remained strong. It was especially pronounced in people with higher body mass index (BMI) and in white participants.
Mitri noted that excess weight is tied to inflammation. “Someone with a higher BMI may have more difficulty responding to insulin,” she said, which can worsen insulin resistance.
“So for people with higher BMI, the same amount of potatoes may have a bigger impact on diabetes risk,” Mousavi said.
The study also found that people who ate more potatoes often took in more calories, sugary drinks, and red meat, and were less physically active—factors that can raise diabetes risk.
TWICE BAKED POTATOES ARE EVEN BETTER
“This points to what the fries are cooked in, instead of the potato being the issue.”
Bingo.
I’ve heard you only have to refrigerate them. I wonder what the truth is. Neither? Both?
Fries 3x per week. Yeah, that would be a glucose load. Did they correlate that study with drinking soda at the same meal?
Berberine. I’m not sure if it helps, but I’m trying it, with other supplements, too. Only because I want to lose a few pounds. My numbers are all great. I attribute that, in part, to walking 30-45 minutes EVERY DAY, and eating mostly healthy foods, though sometimes I break down and treat myself.
very badly designed study because it assumes all frying oils are the same, with no distinction between healthy animal fat oils like tallow or olive or avocado oil and total garbage oils like cottonseed oil and soybean oil ... i mean, whoever thought that cottonseed oil is something that would be fit for human consumption?
they haven’t proved whether the unhealthiness is from the cooking method or the cooking ingredients ...
I can eat a baked potato any time of day...
Except the skin... Grew up being warned that you “must” eat the skin...
IAC, a long time ago, potatoes were the principal driving force in humanity’s recovery from the black death...
At least that’s what my grandparents told me back in the 1930s & 1940s...
I buy small organic potatoes, scrub and cut in half. no need to peel them. I steam them. Steaming is the easiest way to cook them and preserves the most nutrients. Smash them up a bit on my plate, pour on evoo and sprinkle organic parsely on top. No salt. Very yum, not many calories.
All the stores in my neighborhood have organic potatoes. Natural Grocer sometimes has purple potatoes. They have anti-cancer properties.
BTW, I weigh 116. Eat really good and often organic food. Far cheaper than doctor bills.
I use an air fryer. It’s a miracle tool I use quite a bit
Great little cooking recipe. :)
Tanks everyone. I need to get these numbers down. Too close.
Yep, the best french fries I ever had were fried in duck fat. I got them from a food truck.
Where do you get duck fat, though? Can you buy it at the store?
What about hash browns? Asking for a friend, er... I mean my stomach.
Nothing wrong with the potato.
Reevaluate.
Easy:
Stop eating junk, stop eating restaurants.
Cook, enjoy food, end T2D.
Now I’m suddenly dreaming of French fries. 😉
Yes, we got ours through Walmart vendor online. Pure duck fat, doesn’t need refrigerating until opened. The name of it was “good vittles” duck fat. Walmart isn’t carrying it anymore evidently, but they do,have other smaller options- but Amazon has it, and several online vendors carry it.
This is what we bought- 2 gallons, five lbs.
https://www.amazon.com/Antibiotic-Free-Duck-Fat-Gallons/dp/B01M1LON19
It’s expensive, but, you can strain the duc, fat after frying fries or potatoes or whatever really. And reuse it several times. We use a cheese cloth to strain it. Plop it in fridge, and scoop out what we need next time. Once it starts losing its flavor somewhat, we use it then for cooking eggs till it’s gone.
I enjoy my potatoes distilled.
Also, cook fingerling potatoes in the fat, stirring often to coat all the potatoes. Throw on some dill. Salt pepper and wow! Good eats!
I’d also imagine that hashbrowns would be really good cooked in it too.
I gotta try to find goose fat somewhere too. We also use beef tallow, though I don’t really taste much flavor with it like I do with duck fat.
I don’t but thanks. The elevated A1C is from prednisone. Therefore asking help. But thanks, not a junkie and never eat out.
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