Not all vegetables control sugar! Study: Eating too much of these vegetables may increase the risk of diabetes by 11%
Many people with high blood sugar and diabetes have heard doctors tell them to eat more vegetables, moderate amounts of meat, and a small amount of staple food at each meal. But some people find that even though they eat a lot of food every day, their blood sugar remains high. Don’t blame yourself for lack of self-discipline yet – the problem is probably with the “vegetables” you eat.
Recently, a study involving nearly 200,000 people and a follow-up period of more than 30 years confirmed that not all vegetables can help control sugar. If you eat too much of these vegetables, you will not only be unable to control your blood sugar, but may also increase your risk of diabetes.
If you eat too much of these vegetables,
Diabetes risk increased by 11%
In May 2026, a major study published in the international journal "Diabetes Care" completely overturned many people's perceptions: not all vegetables (dietary fiber) can prevent type 2 diabetes. Grain fiber and fruit fiber have outstanding effects, but some starchy vegetable fibers can actually increase the risk of diabetes.
This study involved nearly 200,000 people and was followed up for 34 years. The final results broke many people's inherent perceptions: There is a significant gap in the protective effect of dietary fiber on blood sugar from different sources.
(1) Cereal fiber - a real expert in controlling sugar
Among all dietary fibers, cereal fiber is far ahead in its ability to control sugar. Data shows that people with the highest intake of grain fiber have a 23% lower risk of type 2 diabetes than those with the lowest intake. A more intuitive incremental effect: for every 5 grams more cereal fiber eaten per day, the risk of diabetes decreases by 16%.
Studies have found that higher grain fiber intake is directly related to better insulin sensitivity, blood lipids, and inflammation indicators, which can alleviate insulin resistance from the root cause. More importantly, its glucose-protecting effect does not entirely depend on weight loss. Even if the weight does not change, insulin sensitivity can be improved.
(2) Fruit fiber - has a significant sugar-protecting effect
Second only to grain fiber, it is the fruit fiber we eat daily, and its ability to control sugar is equally impressive. Data show that people who consume the most fruit fiber have an 18% lower risk of developing diabetes than those who consume the least. The incremental benefits are also outstanding: if you consume 5 grams more fruit fiber per day, the risk of disease can be reduced by 14%.
Pectin, the core component of fruit fiber, can nourish intestinal beneficial bacteria, generate butyric acid, help regulate the gluconeogenesis process in the liver, improve insulin activity throughout the body, and inhibit chronic inflammation. But the premise is to eat the whole fruit, squeeze it into juice and filter out the fiber. What is left is basically sugar water.
(3) Vegetable fiber – some may increase risk
The most surprising thing is vegetable fiber, which everyone is most optimistic about. The study found that people with the highest vegetable fiber intake had an 11% higher risk of developing diabetes than those with the lowest intake.
Why eat more starchy vegetables?
On the contrary, does it increase the risk of diabetes?
Dietary fiber has always been regarded as a "healthy tool" for controlling sugar and preventing diabetes. However, many people have found that if they insist on eating more vegetables to supplement fiber, the risk of diabetes increases instead of decreasing. In fact, it’s not that vegetable fiber is useless, but we may be eating the wrong kind!
The research team pointed out that the problem lies in starchy vegetables, that is, commonly eaten vegetables such as potatoes, sweet potatoes, yams, corn, and taro. Although they contain dietary fiber, they have high starch content and high glycemic load.
Many people's dietary misunderstanding is that after eating these starchy vegetables, they still eat staple foods such as rice and noodles as normal, which is equivalent to consuming double carbohydrates in one meal. Long-term excess carbohydrates will continue to increase the burden on insulin secretion, induce insulin resistance, and ultimately increase the risk of diabetes.
In addition, cooking methods can also offset the sugar-controlling value of vegetables. Stewing, braising, thickening and other methods will cause vegetables to absorb a large amount of fat and added sugar, completely eliminating the metabolic benefits brought by fiber. This is also the key reason why vegetable fiber seems to be "sugar-causing".
The truly safe sugar-control vegetables are non-starchy vegetables such as green leafy vegetables, broccoli, cucumbers, and tomatoes.
Therefore, the core of sugar control and fiber supplementation is: to select cereals and whole fruits, replace staple foods with starchy vegetables, and cook light foods to truly protect blood sugar health.
Pay attention to 5 details when consuming dietary fiber.
To truly stabilize blood sugar
How to eat dietary fiber to truly stabilize blood sugar? The "Chinese Diabetes Medical Nutrition Treatment Guidelines (2022 Edition)" clearly states that eating 25 to 36 grams of dietary fiber from food every day, especially 10 to 20 grams of soluble dietary fiber per day, is helpful for sugar control.
1. Half of the staple food should be whole grains to supplement grain fiber.
Replace at least half of the daily polished rice and white flour with oats, brown rice, quinoa, and whole wheat products. If you consume about 9 grams of grain fiber every day (about 100 grams of raw oats + 50 grams of brown rice), the risk of diabetes can be greatly reduced.
2. Eat enough whole fruits and stay away from juices and dried fruits.
Eat 200 to 350 grams of fresh fruit every day, with priority given to apples, pears, prunes, dragon fruit, kiwis, oranges, strawberries, etc. Fruits that can be eaten with the skin should be eaten with the skin as much as possible to retain more pectin; avoid using juice, dried fruit, or candied fruit as substitutes.
3. Choose the right types of vegetables and eat starches as staple food
Eat more than 500 grams of non-starchy vegetables every day, and ensure that your meals include a variety of vegetables.
Green leafy vegetables: celery, spinach, kale, leeks, lettuce, etc.;
Root cauliflowers: broccoli, cauliflower, asparagus, carrots, etc.;
Fungi and algae ingredients: shiitake mushrooms, enoki mushrooms, fungus, kelp, wakame, etc.
If you eat starchy vegetables such as sweet potatoes, corn, yams, etc., you need to reduce your intake of rice and noodles accordingly and avoid superimposing staple foods.
4. Drink more water and eat fiber gradually
If you usually eat little dietary fiber, do not increase it suddenly, otherwise it may cause bloating, gas, or even diarrhea. It is recommended to increase dietary fiber by 5 to 10 grams per week and drink 1.5 to 2 liters of water every day to help dietary fiber work in the intestines.
5. Pay attention to cooking methods and avoid deep-frying
Over-processing destroys the physical structure of the fiber and also results in the loss of other nutrients. Try to choose simple cooking methods such as steaming, boiling, quick-frying, and eating raw (such as salad), and avoid deep-frying and long-term stewing.
Write at the end:
Controlling sugar never has to go to extremes. You don’t need to cook every meal, and you don’t need to completely give up all your favorite foods. Starting today, try to adjust the structure of your dinner plate: arrange more green leafy vegetables, include high-starch ingredients such as potatoes, yams, and lotus roots as staple foods, and pair it with a handful of whole grains every day, plus an appropriate amount of fresh fruit. Just such small adjustments to your eating habits can help you easily stabilize blood sugar fluctuations.
