Prediabetes is a condition where blood sugar levels are higher than normal, but not high enough yet to be diagnosed as type 2 diabetes. An estimated 88 million American adults have prediabetes, and it can often lead to the development of type 2 diabetes if left untreated. Making changes to your diet is one of the most effective ways to manage prediabetes and prevent or delay the onset of type 2 diabetes. Understanding which carbs are OK to eat and which to limit or avoid can be an important part of a prediabetes diet plan.
What is prediabetes?
Prediabetes means your blood sugar levels are higher than normal but not yet high enough to cross the threshold into type 2 diabetes. It signifies you are at increased risk for developing type 2 diabetes as well as heart disease and stroke. Some key facts about prediabetes:
- Prediabetes is diagnosed by blood tests showing impaired fasting glucose levels between 100-125 mg/dL, impaired glucose tolerance with 2-hour glucose levels between 140-199 mg/dL after a 75 gram oral glucose tolerance test, or an A1C between 5.7-6.4%.
- Prediabetes can exist for years without clear symptoms so many people are unaware they have it.
- Up to 30% of people with prediabetes will develop type 2 diabetes within 5 years if no action is taken.
- Making lifestyle changes like diet, exercise and weight loss can prevent or delay progression to type 2 diabetes in people with prediabetes.
If you have been told you have prediabetes, it means you are at a critical time where you can take steps to prevent type 2 diabetes. Adjusting your carbohydrate intake and making wise carbohydrate choices is essential for managing prediabetes.
Why carbs impact blood sugar
Carbohydrates are one of the main nutrients that affect blood sugar levels. This is because carbs break down into glucose during digestion, causing an increase in blood glucose. Foods that contain carbohydrates raise blood sugar levels more than foods that contain mostly protein or fat.
Simple carbs or refined carbs tend to have the biggest impact on blood sugar. They break down quickly and can lead to spikes in blood glucose levels. Complex carbs break down more slowly and have less of an effect. Fiber in carbs also helps blunt the impact on blood sugar.
When you have prediabetes, being mindful of your carbohydrate intake and sticking to the healthiest carb choices can help keep your blood sugar stable. Paying attention to the total amount of carbs you eat at a meal is also key to controlling blood sugar with prediabetes.
Carbohydrate Guidelines for Prediabetes
General carb guidelines that can help manage prediabetes:
Limit total carb intake
– Aim for 100-150 grams of total carbs per day
– Focus carb intake in fruits, vegetables, whole grains
– Limit carb-heavy processed foods and desserts
Eat the right types of carbs
– Emphasize complex, fiber-rich carbs – vegetables, fruits, whole grains
– Minimize added sugars and refined grains like white bread, white rice
Spread carbs evenly
– Don’t overload carbs at any one meal
– 30-45 grams per meal and 15-30 grams per snack
Pair carbs with protein, fat and fiber
– Helps slow digestion and prevent blood sugar spikes
– Ex: whole grain toast with peanut butter; oatmeal with nuts and berries
Following these basic carb guidelines can help normalize blood sugar levels and manage prediabetes. But not all carbs are created equal when it comes to their effects on blood sugar. Let’s take a closer look at the best and worst carb choices.
Best Carbs for Prediabetes
Focusing on the healthiest carb foods that are digested slowly and have a lower glycemic impact can help maintain healthy blood sugar levels. Here are some of the best carb choices when you’re managing prediabetes:
Non-Starchy Vegetables
Non-starchy vegetables are carb superstars. They are packed with vitamins, minerals and fiber with minimal effects on blood sugar. Enjoy these low glycemic veggies generously as part of a prediabetes diet:
- Broccoli
- Carrots
- Cauliflower
- Celery
- Cucumbers
- Leafy greens – spinach, kale, collards
- Onions
- Peppers
- Tomatoes
- Summer squash – zucchini, yellow squash
- Asparagus
- Mushrooms
- Brussels sprouts
- Green beans
- Eggplant
These vegetables provide no more than 5 grams of carbs per cooked cup. They have a minimal effect on blood glucose so you can eat them freely to satisfy carb cravings.
Berries
All types of berries are great fruit choices. They provide fiber and antioxidants along with natural sweetness. Berries have a low glycemic impact compared to other fruits.
- Blueberries
- Blackberries
- Raspberries
- Strawberries
Aim for 1⁄2 to 1 cup fresh or frozen berries daily. Avoid added sugars in sweetened yogurt or jams with berries.
Stone Fruits
Stone fruits like peaches, nectarines, plums and cherries contain fiber, vitamins and just 12-19 grams of carbs per cup. Their low glycemic impact makes them a smart fruit choice for a prediabetes eating plan. Eat them fresh or opt for unsweetened frozen, canned or dried versions.
Citrus Fruits
Oranges, grapefruit, clementines and other citrus fruits have a low glycemic index thanks to their fiber and vitamin C content. Enjoy a small orange or grapefruit with breakfast or as a snack to get in valuable fruits servings.
Whole Grains
Whole, minimally processed grains are complex carbs preferred for diabetes management. They take longer to digest and provide important nutrients like fiber, B vitamins, magnesium and chromium. Best whole grain choices:
- Oats – steel cut oats, old fashioned oats, oat bran
- Quinoa
- Brown rice
- Barley
- Buckwheat
- Bulgur
- Whole grain bread
- Whole wheat pasta
Aim for 2-3 servings of whole grains daily, measured to 1⁄2 cup cooked grains or breads. Spread out your intake throughout the day.
Starchy Vegetables
Starchy vegetables like potatoes, sweet potatoes, corn and peas have more carbs and a higher glycemic impact than non-starchy veggies. But they still provide important nutrients. Have 1⁄2 cup serving as the equivalent of 1 carb choice. Sweet potatoes and carrots are healthier options than white potatoes.
Legumes
Legumes like beans, lentils and peas are filling protein sources that also provide fiber to blunt blood sugar spikes. They contain about 15-25 grams of digestible carbs per 1⁄2 cup cooked serving. Enjoy legumes a few times a week, being careful with portion sizes.
Low-Fat Dairy
Milk and yogurt contain calcium, potassium and protein. Opt for low-fat versions and stick to a 1 cup milk serving or 1⁄2 cup plain yogurt daily as part of a balanced prediabetes diet. Avoid added sugars in flavored yogurts and sweetened milk products.
Worst Carbs for Prediabetes
To help keep blood glucose levels in check, there are certain carbs best limited or avoided when you have prediabetes. These include:
Sugary Drinks
Soda, fruit juice, sports drinks, sweet teas and other sugar-sweetened beverages are the worst offender for diabetes and prediabetes. They provide excessive carbs and calories in liquid form that is quickly absorbed and rapidly spikes blood glucose. Avoid drinking calories and hydrate with water instead.
White Bread, Pasta, Rice
Refined grains like white bread, bagels, crackers and white pasta and rice act similar to sugar in the body. Choosing whole grain options like whole wheat bread and brown rice is much better for blood sugar control.
Pastries and Baked Goods
Cookies, cakes, muffins, donuts and other baked treats are loaded with refined carbs and provide little nutritional value. It’s best to eliminate these high glycemic index foods when managing prediabetes.
Candy and Chocolate
Sweets and candy made with sugar, high fructose corn syrup, and refined carbohydrates can spike blood sugar quickly. Limiting these foods helps with glycemic control.
Fruit Juice
Even 100% fruit juice is high in natural sugars with little fiber to slow absorption. Juice spikes blood glucose rapidly, so it’s best to avoid it if you have prediabetes. Eat the whole fruits instead for more fiber.
Packaged Snacks
Snack foods like chips, pretzels, crackers, granola bars and sugary baked goods have refined carbs that digest easily and affect blood sugar. Focus snack time on fiber-rich fruits, vegetables and whole grains instead.
Jams and Honey
These common sweeteners are types of added sugars with a high glycemic index. Use occasionally and focus on getting natural sweetness from fruits and higher fiber choices like unsweetened applesauce.
Dried Fruits
Dried fruits like raisins, cranberries and cherries are concentrated sources of fruit sugar. It’s easy to overeat dried fruit, so stick to 2-3 Tbsp portion sizes to keep glycemic impact in check.
Sugary Cereals
Many breakfast cereals, even those marketed as healthy, are actually packed with refined carbs and sugar. Choose unsweetened oatmeal or whole grain cereals under 5 grams sugar per serving.
Frozen Meals
Packaged frozen meals and entrées often have fillers, processed carbs and added sugars. Read labels and choose lower carb options whenever using frozen convenience foods.
Following a low glycemic diet by limiting high glycemic index carbs and focusing on foods that release glucose slowly is the best approach for managing prediabetes and blood sugar levels. Paying attention to both the quality of carbs and appropriate portions can help keep post-meal glucose spikes under control.
Healthy Carb Servings for Prediabetes
When planning meals, use the following as a general guide for carb servings depending on your daily carb target:
Carb Target: 150 grams per day
- Non-starchy veggies – Unlimited
- Starchy veggies – 1-2 servings, about 1⁄2 cup per serving
- Fruit – 2 servings, 1⁄2 cup or small whole fruit
- Whole grains – 2-3 servings, about 1⁄2 cup per serving
- Dairy – 1 serving, 1 cup milk or yogurt
Carb Target: 120 grams per day
- Non-starchy veggies – Unlimited
- Starchy veggies – 1 serving, 1⁄2 cup
- Fruit – 1-2 servings, 1⁄2 cup or 1 small fruit
- Whole grains – 2 servings, about 1⁄2 cup per serving
- Dairy – 1 serving, 1 cup milk or yogurt
- Legumes – 1⁄2 cup a few times per week
Carb Target: 90 grams per day
- Non-starchy veggies – Unlimited
- Berries – 1 serving, about 1⁄2 cup
- Other fruit – 1 serving, 1⁄2 cup
- Whole grains – 1-2 servings, about 1⁄2 cup per serving
- Dairy – 1 serving, 1 cup milk or yogurt
The best approach is to work with a healthcare provider or dietitian to determine the carb intake and eating plan that meets your health goals and diabetes prevention needs. Tracking your daily carbohydrate intake can also help you stay within your personalized targets.
Sample Menu for a Prediabetes Diet
Here is a one day sample menu for a prediabetes diet based on the carb serving guidelines:
Breakfast
– 1⁄2 cup old fashioned oats cooked with cinnamon, 1 Tbsp ground flaxseed and 1⁄4 cup blueberries
– 1 cup unsweetened almond milk
– 1 hardboiled egg
– Coffee with 1 Tbsp half and half
Snack
– 1 medium apple with 1 Tbsp almond butter
Lunch
– Turkey and avocado sandwich on 2 slices whole grain bread: 3 oz turkey, 1⁄4 avocado spread, lettuce, tomato, onion
– Side salad: 1 cup mixed greens, 1⁄4 cup chickpeas, 1⁄4 cup cucumber, 1⁄4 cup cherry tomatoes, 2 Tbsp balsamic vinaigrette
Snack
– 15 whole grain crackers with 1 wedge laughing cow cheese
Dinner
– 4 oz baked salmon
– 1⁄2 cup roasted Brussels sprouts
– 1⁄2 cup brown rice
– 1 cup roasted cauliflower
Dessert
– 1⁄2 cup mixed berries
– 2 Tbsp plain Greek yogurt
– 1 Tbsp chopped walnuts
Tips for Healthy Carb Eating with Prediabetes
Here are some helpful tips for managing your carb intake when you have prediabetes:
- Read food labels – Look at total carb content as well as sugar and fiber amounts
- Measure portion sizes – Use measuring cups and food scale for better portions
- Choose ‘smart carb’ alternatives – Cauliflower rice or zucchini noodles instead of grains
- Always eat carbs with protein, fat and fiber – This helps control blood sugar response
- Time carb intake – Eat more carbs after exercising when cells are primed for glucose uptake
- Avoid carb-heavy meals – Spacing carbs evenly throughout the day is ideal
- Reduce highly processed carbs – Pick whole foods over refined and packaged products
- Manage carb cravings – Have a fiber-rich snack like vegetables with hummus
Tracking your meals in an app can also help ensure you stay within your carb range at each meal and snack.
Conclusion
Managing carbohydrate intake wisely is essential for controlling blood sugar levels with prediabetes. Focus on getting carbs from high fiber whole food sources like non-starchy vegetables, fruits, beans, lentils, whole grains and low-fat dairy. Avoid refined grains, added sugars and processed carbs. Pay attention to both carb quality and portions. With the right carb modifications and choices as part of an overall balanced eating pattern, you can help get your blood glucose under control and prevent or delay type 2 diabetes. Work with your healthcare provider on the optimal carb intake goals for your individual health needs.
