A person with prediabetes has blood sugar levels that are high but not yet within the diabetes ranges. There is still time to control the levels and prevent diabetes from developing.

In the United States, 34.5% of adults have prediabetes.

Having prediabetes does not guarantee that diabetes will develop, but it does increase the risk. Taking preventive action, such as losing 5–7% of body weight, can reduce this risk, according to the Centers for Disease Control and Prevention (CDC).

If a person takes the right steps, there is a good chance that they can prevent diabetes from developing. Prevention plans usually involve two key lifestyle factors: a healthful diet and regular exercise.

This article explores how the diet and prediabetes are related and provides some tips for managing blood sugar levels.

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Results from the CDC show that people who lost 5–7% of their body weight and performed 150 minutes of exercise per week reduced their risk of developing type 2 diabetes by 58%.

A diet that can help a person lose weight and manage prediabetes typically includes foods that are:

  • high in fiber
  • low in added sugars
  • dense in nutrients

People should eat plenty of:

Reaching and maintaining a moderate weight can help prevent type 2 diabetes from developing. Paying attention to overall calorie intake is a key step.

It can help to avoid:

Excessive amounts of saturated fats can also raise cholesterol levels and contribute to the risk of cardiovascular disease.

Learn more about the relationship between cholesterol and diabetes here.

While limiting the intake of certain foods can reduce a person’s risk of developing diabetes, establishing a balanced diet as part of a healthy lifestyle is the best way to manage prediabetes.

The glycemic index (GI) is a list of foods that contain carbohydrates. The ranking shows how quickly these foods raise blood sugar levels. The highest score is 100, and the lowest is 0.

People with diabetes need to be mindful of their carbohydrate intake, especially when the carbs come from added sugars.

However, foods that contain carbohydrates and sugar are not always unhealthy. For example, fruits contain natural sugars, and whole grains are high in carbohydrates, but they provide fiber and other nutrients. This makes them suitable, in moderation, for a person who is following a prediabetes diet.

Sample GI values

Exact GI values depend on brands and specific types of products, but below are the average GI values for 10 common kinds of food and drink.

FoodGI
breads64
pasta52
rice67
potatoes71
breakfast cereals61
fruits51
cookies49
nuts22
confectionary48
dairy products35

It is worth keeping in mind that GI values can change from item to item. Some apples, for example, are sweeter than others.

What makes a low or high GI score?

The body digests whole grain and high fiber foods slowly, and their sugars enter the bloodstream gradually. Foods that contain fiber, such as fruits and whole grains, have lower GI scores than those made with refined ingredients.

The body processes sugars and refined carbohydrates quickly. This causes a quick rise in blood sugar levels, or a “sugar spike.” Foods containing refined carbohydrates and added sugars have high GI scores. This is why white bread has a higher GI value than wholemeal bread.

People with prediabetes should try to avoid foods with high GI scores, because these raise blood sugar levels quickly. However, the overall amount of carbohydrates a person eats has a greater impact on their blood sugar levels than the specific GI scores of foods.

Some GI tips

The following facts can help guide people looking for low GI options:

  • Foods that contain refined sugars usually have higher GI scores than foods that contain natural sugars, such as fruits.
  • Whole foods tend to have lower GI scores than products made with refined grains, such as white bread or rice.
  • Sweet potatoes, most vegetables, whole fruits, and legumes have lower GI scores than white starchy vegetables, such as potatoes.
  • As most fruits and vegetables ripen, their sugar contents increase, and their GI scores go up.
  • Pastas cooked al dente tend to have lower GI scores than pastas cooked for longer.
  • Parboiled rice, basmati rice, and brown rice all have lower GI scores than short grain or jasmine rice.
  • Rolled or steel-cut oats have lower GI scores than quick-cooking oatmeal.

However, researchers have not confirmed whether following a low GI diet helps all individuals manage prediabetes. It is best to ask a doctor or dietitian for specific advice.

For more science-backed resources on nutrition, visit our dedicated hub.

Cutting out carbohydrates is not necessarily healthy. Some high-carbohydrate foods, such as potatoes and peas, have significant nutritional benefits.

However, many low carbohydrate foods can provide the same nutrients. Swapping high carbohydrate foods for lower carbohydrate options can be beneficial for people with prediabetes.

For example, the following starchy vegetables are high in carbohydrates:

  • potatoes
  • peas
  • corn

The following vegetables have fewer carbohydrates per portion and are rich in fiber and other nutrients:

The Institute of Medicine suggests that 45–65% of a person’s diet should contain carbohydrates.

People with prediabetes need to keep their blood sugar levels as steady as possible.

Experts recommend eating regular meals throughout the day to avoid fluctuations. They also suggest making sure that meals are balanced, with each containing a source of protein, fat, and carbohydrates. A person with prediabetes may also find it helpful to eat a consistent amount of carbohydrates at each meal.

The Department of Agriculture has developed this simple way to determine how much of each food type belongs in each meal. Following this method:

  • Nonstarchy vegetables take up half the plate.
  • Meat, fish, or another protein source takes up just under one-quarter.
  • Carbohydrates, such as whole grains, take up just over one-quarter of the plate.
  • There is a serving of dairy on the side.

Health authorities, including the National Institutes of Health (NIH), recommend following the Dietary Approaches to Stop Hypertension (DASH) diet. Combined with an awareness of GI scores, it can help people with prediabetes.

This diet focuses not on counting calories but on making healthy choices.

It encourages people to eat:

  • vegetables
  • fruits
  • whole grains
  • fat-free or low fat dairy products
  • fish
  • poultry
  • beans
  • nuts
  • vegetable oils

And it involves avoiding foods high in saturated fats and sugar, such as:

  • fatty meat
  • full fat dairy products
  • coconut, palm, and other tropical oils
  • candy
  • sugary drinks

However, some research indicates that full fat dairy products, particularly yogurt and cheese, may be beneficial as part of a balanced diet for people with prediabetes.

Numerous studies have found that full fat dairy products do not have a negative impact on insulin sensitivity or blood pressure, and may protect against type 2 diabetes and cardiovascular disease.

Learn more about the DASH diet here.

A person with prediabetes can still enjoy eating in restaurants, but making strategic choices is key.

Here are some tips:

  • Encourage everyone to meet at restaurants with healthy options.
  • Avoid buffets, if it is too tempting to have more than one plate.
  • Aim for quality, such as fresh ingredients, rather than quantity.
  • See if the menu lists the calories in each dish.
  • Opt for sparkling water with ice and a slice of lemon instead of soda or alcohol.

Anyone who has just received a diagnosis of prediabetes may be wondering what they can eat. Here are some suggestions:

MealWhat to eatWhat to avoid
Breakfasteggs

rolled or whole oats

wholemeal bread

peanut butter without added sugar

fruit

up to 4 ounces of 100% fruit juice with no added sugar

coffee or tea with no sugar
white bread and bagels

sweetened breakfast cereals

sweetened juices

“specialty” coffee drinks, as these may contain added sugar
Lunchbaked beans on wholemeal toast

brown rice, lentils, and salad with a little olive oil

homemade vegetable soup

an apple or pear, or a cup of melon or berries
bagels, baguettes, and other white or refined bread

burgers and many fast food items

salad dressings high in added sugars
Dinnersalmon with yam or sweet potato, broccoli, and asparagus

baked chicken with wholemeal pasta, homemade tomato sauce, and salad
pizza

readymade sauces

fatty meats
Snacknuts

fruit

plain, unsweetened yogurt
candy

readymade “health” bars, unless they are very low in added sugar

To reduce the effects on blood sugar and increase feelings of fullness, try pairing fruit with a source of protein or healthy fat, such as nut butter, a small handful of nuts or seeds, or avocado.

People can check with a doctor or dietitian about how much of each favorite food is appropriate to eat.

Alcohol consumption can increase weight and the risk of diabetes. One study, for example, suggests that “risky” alcohol use significantly raises the chance of developing diabetes in men.

Limiting or avoiding alcohol consumption can help people control their blood glucose levels and lose weight.

People with diabetes who do drink alcohol should avoid sugary mixers, such as sodas.

Dietary changes alone may not prevent prediabetes from developing into diabetes. Some other strategies involve exercise and medication.

Exercise

Physical activity can help a person lose weight and control their blood sugar levels. Exercise uses up excess blood sugar and can improve insulin sensitivity.

At least one study suggests that making dietary changes and getting more exercise can prevent the progression from prediabetes to diabetes.

For people with type 2 diabetes, the American Diabetes Association recommends getting up every 30 minutes to do some light walking or resistance training during periods of prolonged sitting. This can help reduce blood glucose levels.

Regular activities that may also help include:

  • swimming
  • brisk walking
  • running
  • strength training
  • flexibility training

Housework, gardening, and other activities can all contribute.

Medications

For some people with prediabetes, doctors may prescribe metformin to help control blood sugar levels.

In people with obesity and prediabetes, metformin can reduce the risk of developing diabetes by up to 31% over 3 years.

While this figure is hopeful, the NIH states that medications do not appear to be as effective as certain lifestyle changes. It also confirms that metformin can have side effects.

RECALL OF METFORMIN EXTENDED RELEASE

In May 2020, the Food and Drug Administration (FDA) recommended that some makers of metformin extended release remove some of their tablets from the U.S. market. This is because an unacceptable level of a probable carcinogen (cancer-causing agent) was found in some extended-release metformin tablets. If you currently take this drug, call your healthcare provider. They will advise whether you should continue to take your medication or if you need a new prescription.

Prediabetes can develop into diabetes, but making strategic changes to diet and exercise habits can often prevent this, especially if the changes happen early.

There is no one-size-fits-all diet for people with prediabetes. Anyone who receives this diagnosis should ask their doctor, a dietitian, or both for advice.

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