Foods with a low glycemic index (GI) may help people lower or manage their blood sugar levels. Examples include whole grains, nuts, legumes, some fruits, non-starchy vegetables, and lean proteins.

For people with diabetes, foods and beverages that the body absorbs slowly are often preferable because they do not cause spikes and dips in blood sugar. Health professionals may refer to these as low GI foods. The GI measures the effects of specific foods on blood sugar levels.

People who are looking to manage their blood sugar levels may want to consider foods with low or medium GI scores. People can also pair foods with low and high GI scores to ensure that a meal is balanced.

However, there is no evidence to suggest that eating a certain type of food can lower a person’s blood sugar levels in a diabetes-related emergency.

Below are some of the best foods for people who are looking to maintain healthy blood sugar levels.

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Consuming less-processed grains can help blood sugar levels in people with type 2 diabetes. Cavan Images/Getty Images

Many kinds of bread have high GI scores and can cause a spike in blood sugar levels. Researchers suggest that low GI eating patterns can improve a person’s blood sugar response over time. Therefore, people with diabetes may consider avoiding several types of bread.

However, consuming whole grain foods has been associated with a lower risk of type 2 diabetes (T2DM). Some breads are a good way to consume whole grain foods.

Pumpernickel bread and 100% stone-ground whole wheat bread have low GI scores. They have lower GI scores than regular whole wheat bread because the ingredients go through less processing. Processing removes the fibrous outer shells of grains and cereals. Fiber slows digestion and helps stabilize blood sugar levels.

The researchers behind a small 2020 trial found that consuming less-processed grains led to an improvement in blood sugar levels for people with T2DM.

A separate small 2020 study involving 15 people with T2DM also found that the particle size of the whole grains in bread had an impact on blood sugar levels. The particle size reflects the grains’ level of processing.

The authors of a 2021 review looked at the effect of millets, which have a low GI score. They found that the regular consumption of millets, including sorghum, reduced average fasting blood sugar levels by up to 12% and decreased postmeal blood sugar levels by up to 15%.

Breads to eat

  • whole wheat, especially stone-ground whole wheat
  • pumpernickel
  • spelt
  • rye
  • rice
  • breads made with ancient grains such as emmer and einkorn
  • breads made from less-processed grains

Breads to avoid

  • white bread
  • bagels
  • breads made from refined or highly milled grains
  • breads with added sugar
  • fruit breads and raisin toast

Except for pineapples and melons, fruits generally have low GI scores. This is because most fresh fruits contain lots of water and fiber to balance out their content of fructose, a naturally occurring sugar.

However, as fruits ripen, their GI scores increase. Fruit juices also typically have very high GI scores because juicing removes the fibrous skins and seeds. So, fresh fruit is preferable.

A 2017 study that followed about half a million people in China for 7 years found that those who ate fresh fruit daily had lower rates of T2DM.

Fruits to eat

  • apples
  • apricots
  • avocadoes
  • blackberries
  • blueberries
  • grapefruit
  • grapes
  • peaches
  • plums
  • raspberries
  • strawberries

Fruits to enjoy in moderation

  • dried fruit
  • watermelon
  • pineapple
  • fruit juice
  • overripe bananas
  • dates

White potatoes have a high GI score. Sweet potatoes and yams have lower scores — although they are still relatively high — and are very nutritious.

Sweet potatoes are a good source of fiber, potassium, zinc, and vitamins A and C. Health experts may recommend sweet potatoes as a suitable substitute for white potatoes in a variety of dishes, from fries to casseroles.

In addition to trying to include more sweet potatoes and yams, people may want to limit or avoid white potatoes and products typically made from them, such as french fries and mashed potatoes.

Oats have a low GI score, which means they are less likely to cause spikes and dips in blood sugar levels.

Oats also contain beta-glucan, which can:

  • reduce glucose and insulin responses after meals
  • improve insulin sensitivity
  • help regulate blood sugar
  • reduce levels of blood lipids (fats)

The authors of a 2021 meta-analysis of 103 trials looked at how beta-glucan affects blood sugar levels after a meal. They found evidence to suggest that carbohydrate-based meals that contain beta-glucan have a link to lower blood sugar levels than meals that do not contain beta-glucan.

Stone-ground and rolled oats are typically the preferable forms to consume. People may wish to limit other forms, such as processed oats, instant oats, and cereal bars.

Nuts are very rich in dietary fiber and have low GI scores.

Nuts also contain high levels of plant protein, unsaturated fatty acids, and other nutrients, including:

The American Diabetes Association notes that nuts can be beneficial for diabetes and are a good source of fiber and omega-3 fatty acids.

As with other foods in this article, it is best to eat nuts that are as whole and as unprocessed as possible. Nuts with coatings or flavorings have higher GI scores than plain nuts.

Nut products to eat

  • raw almonds
  • raw cashews
  • raw walnuts
  • raw pecans
  • other tree nuts
  • raw peanuts
  • unsweetened peanut butter
  • sunflower seeds

Nuts with higher GI scores

  • cashews
  • macadamia nuts
  • roasted or salted nuts
  • candied nuts

Legumes, such as beans, peas, chickpeas, and lentils, have very low GI scores. Even baked beans, which are not as preferable, still have a low GI score.

Legumes are also good sources of nutrients that can help people maintain healthy blood sugar levels, including:

  • fiber
  • complex carbohydrates
  • protein

People with diabetes may wish to avoid legume products that contain added sugars and simple starches, such as legumes packaged in syrups, sauces, or marinades. These additions can significantly increase a product’s GI score.

Legume products to eat

  • black beans
  • pinto beans
  • green beans
  • lima beans
  • navy beans
  • black-eyed peas
  • chickpeas
  • lentils
  • snow peas
  • hummus

People may wish to avoid consuming any beans with added sugar.

Garlic is a popular component of traditional remedies for diabetes and a wide variety of other conditions. The compounds in garlic may help lower blood sugar by improving insulin sensitivity and secretion.

The authors of a 2017 review found that garlic supplements helped manage blood sugar and cholesterol levels in people with T2DM.

Ways to add garlic to the diet

  • eating it raw
  • chopping it and adding to dips, savory spreads, and salad dressings
  • sauteing it with vegetables
  • adding it to cooked meals
  • taking garlic capsules

Fish and other animal proteins do not typically have GI scores because they do not contain carbohydrates.

However, consuming fish that contain the omega-3 fatty acids docosahexaenoic acid and eicosapentaenoic acid may help manage or prevent diabetes better than consuming other types of animal protein.

The researchers behind a 2021 study found that people who consumed oily fish developed T2DM at lower rates than those who did not.

Also, in a small 2017 study, participants who ate plenty of fatty fish showed better blood sugar regulation after a meal than those who avoided fish.

While more research is necessary, some evidence suggests a potential link between mercury and T2DM. Health experts recommend limiting fish high in mercury, especially for children, pregnant people, and those who are nursing.

Fish products to eat

  • anchovies
  • cod
  • haddock
  • herring
  • pollock
  • salmon
  • sardines
  • fish oil capsules

Fish to limit

  • bigeye tuna
  • king mackerel
  • marlin
  • shark
  • swordfish
  • tilefish

While more research is necessary, some evidence suggests that yogurt consumption, as part of a healthy dietary pattern, may help reduce the risk of T2DM. Evidence notes that yogurt can provide many other health benefits. And because eating yogurt can help people feel fuller, it may help with blood sugar management.

It is best to avoid sweetened or flavored yogurts, which often contain more sugar than is desirable for a person who is looking to lower their blood sugar levels. Greek-style yogurt and unsweetened yogurt can be healthy alternatives.

Eating a healthy, well-balanced diet is key. Additional strategies to help lower or manage blood sugar levels include:

  • staying hydrated by drinking plenty of clear liquids
  • staying active throughout the day
  • eating small portions more often
  • not skipping meals
  • managing or reducing stress
  • maintaining a moderate body weight or losing weight, if appropriate

People with diabetes may also need to take medications and check their blood sugar levels regularly to reduce the risk of experiencing potentially dangerous symptoms and complications.

People can consult a doctor about how to incorporate a healthy diet into a diabetes care plan.

Below are frequently asked questions relating to diet and blood sugar control.

What foods are good for hyperglycemia?

Choosing healthy proteins and fats and non-starchy vegetables can help manage hyperglycemia. Carbohydrates that are lower in sugar and contain fiber are less likely to spike blood sugar compared to refined carbs.

Good carbohydrate choices include:

  • bread
  • oatmeal
  • potatoes
  • fruits
  • yogurt
  • legumes

Lean proteins like chicken, oily fish, and non-starchy vegetables can also be good choices for hyperglycemia.

What foods cause hyperglycemia?

Hyperglycemia occurs due to a lack of insulin or insulin resistance. The root cause of hyperglycemia can often be multifactorial and depends on a person’s inherited risk factors, overall health status, diet, and lifestyle. However, a diet high in processed carbohydrates and sugars can increase the risk of blood sugar spikes.

What foods to avoid if you have hyperglycemia?

High-sugar foods and simple, refined carbohydrate products are best to limit when managing hyperglycemia. Things to specifically limit or avoid include:

  • sodas
  • sweet desserts
  • pastries
  • sugar-sweetened coffees, teas and smoothies
  • white bread and pasta

What foods will lower blood sugar quickly?

The fastest way to lower blood sugar is to take fast-acting insulin medication. Exercise can also help to bring down blood sugar levels quickly. Diet and lifestyle changes can help manage overall blood sugar levels, but for immediate action, prescription medication or medical assistance may be necessary.