Blood Sugar

Prevent Blood Sugar Spikes When Eating Carbs

Can people with prediabetes avoid blood sugar spikes when eating carbs? You can actually do some good by eating the right ones!
Eating Carbs and having diabetes, can I do both?
Natalie Stein

Exercise, Fitness & Nutrition Expert | Lark Health

What do you think of when you think of blood sugar spikes and the foods you eat? Carbohydrates are likely to come to mind since they get a good amount of attention when talking about prediabetes, diabetes, and blood sugar. They can be harmful, but a generalization that “carbs are bad” is not true.

People with prediabetes can eat carbohydrates without spiking blood sugar levels, gaining weight, or doing other harm to their health. Not only can you avoid harm from eating carbohydrates, but you can actually do some good for your health by eating the right ones in the right ways.

Lower your risk of diabetes at no cost

Take the survey
Weight 160lbs
Height 64

Types of Carbs in Food

Sugar-Sweetened Breakfast Cereals

Different types of carbohydrates have different effects on your body and blood sugar levels. The main types of carbohydrates in food are sugars, starches, and fiber. Sugars are small molecules that your body can quickly break down into a type of sugar called glucose, which enters your bloodstream and causes higher blood glucose, or blood sugar, levels. Some sugars are naturally in foods such as fruit and dairy products, but most of the harm comes from consuming sugars that are added to foods such as sweets, soft drinks, sweetened foods such as cereal and flavored yogurt, and sugar-sweetened condiments.

Starches are long, sometimes complex, chains of glucose. Though they take longer to break down than simple sugars, they are still able to enter your bloodstream relatively quickly in the form of glucose. Sources include bread, pasta, rice, cereal, other grain products, beans, potatoes, butternut squash, corn, and other starchy vegetables.

Fiber is another brand of carbohydrate. While sugars and starches bump up blood glucose, and your body gets 4 calories per gram from them, your body is unable to digest fiber. Instead, it goes into your gut where bacteria ferment some of it. Fiber lowers cholesterol levels and helps stabilize blood sugar because it slows digestion. 

Why Eat Carbs

Baked sweet potato with non-fat plain yogurt

You need a tiny amount of carbohydrates for survival, but eating more than that can allow you to get more nutrients because carbohydrates are in many healthy foods. Research has shown links between consumption of nutrient-dense high-carbohydrate foods, such as whole grains, fruit, sweet potatoes, and lentils, and lower risk for obesity, diabetes, certain types of cancer, and heart disease. They are rich in nutrients such as potassium and antioxidants. That is why Lark DPP may suggest eating these types of high-carbohydrate foods even with prediabetes or when trying to lose weight.

Carbs and Blood Sugar Spikes – A Roller Coaster


As the Lark DPP check-in described, eating carbohydrates leads to a bump in blood sugar. Eating a lot of sugary foods and refined starches can cause fast and sharp spikes in blood sugar. This triggers the pancreas to release insulin to get blood sugar back down, and blood sugar may end up lower than it was when it started. Low blood sugar can make you tired and cranky, and increase cravings for – you guessed it – more carbs.

The bigger the spike, the bigger the dip. Have a sugar-sweetened coffee beverage and sugary, refined cereal for breakfast, and a sharp, high spike may have you bouncing off the walls for an hour before you crash right in time to sleep through a mid-morning meeting. Similarly, a desperate trip to the vending machine for pretzels and a soda can give you the instant pick-me-up you wanted…followed by a lackluster afternoon.

Choosing The Right Carbs


A good rule of thumb to choosing carbohydrates is to pick reduced-fat dairy products and high-fiber sources of carbohydrates. In general, less-processed foods are higher in fiber, less likely to spike blood sugar, and higher in natural nutrients, than more-processed ones. Typically, these are good choices.

  • Whole nuts and peanuts instead of peanut and nut butter.
  • Whole grains, such as oatmeal, whole wheat bread, brown rice, and whole-grain cereal, instead of refined grains, such as white rice, pasta, and bread and refined cereal.
  • Fresh or unsweetened frozen fruit rather than dried fruit or fruit juice.
  • Baked sweet potato with skin instead of mashed potatoes.

Adding fiber in the form of non-starchy vegetables is almost always a good idea since they are low in calories and other carbohydrates.

Make It a Meal

Savory Oatmeal

By adding a source of protein and some healthy fat, the meal or snack can not only be balanced but have less of a negative effect on blood sugar. Protein and fat slow down digestion so blood sugar does not spike as quickly. These are some sample combinations.

  • Oatmeal with cottage cheese and sunflower seeds.
  • Whole-grain pasta with broccoli, olive oil, and cooked shrimp.
  • Fruit salad with walnuts and feta cheese.
  • Lentil soup with Greek yogurt and avocado.
  • Brown rice with olive oil, sliced almonds, and vegetables.

Size Matters

Serving and Portion Sizes Explained

Just like with weight loss, size matters for controlling blood sugar. A serving size of carbohydrates is smaller than most restaurants and many packaged foods may lead you to believe. A serving is a slice of bread, a half-cup of cooked pasta, beans, or oatmeal, or cup of fresh fruit. A healthy amount for most people at a single meal is 2 to 3 servings, such as the carbohydrates in the following examples.

  • Peanut butter sandwich on a whole-grain English muffin and a cup of strawberries.
  • 1 cup of pea soup with turkey.
  • 1 cup of three-bean salad and 1 ounce of whole-grain pretzels.
  • ½ cup brown rice, ½ cup fat-free refried beans, and avocado and shredded chicken
  • 1 cup cooked whole-grain pasta tossed with salmon, basil, and olive oil.
  • Veggie burger on a whole-grain bun with lettuce and tomato.

Lower your risk of diabetes at no cost

Take the survey
Weight 160lbs
Height 64

Too much of the wrong kind of carbohydrates can lead not only to weight gain, but to spikes in blood sugar and insulin. Too many of these spikes contribute to insulin resistance, or prediabetes and diabetes. On the other hand, smart carb choices and amounts can have the opposite effect. Lark DPP can help you turn making the right choices into habits that fit into your lifestyle.