When ‘Healthy’ Foods Spike Blood Sugar — and What You Can Do About It

Many nutrient-packed foods we think of as healthy — smoothies, plant-based milks, grain bowls — still cause blood sugar spikes for some people. “It’s not that certain foods are bad,” says Anar Allidina, MPH, a registered dietitian based in Toronto who specializes in prediabetes and insulin resistance. “Their processing level, structure, and quantity all influence how quickly blood sugar rises.”

The good news: You don’t have to cut these foods from your meal plan. If they contribute to unhealthy blood sugar fluctuations, small tweaks, such as combining them with protein or fiber, adjusting portion sizes, and timing meals differently, can help your body respond more effectively to support steady blood sugar levels.

What you eat matters, but how your body processes those foods is also important. Foods that are more broken down (such as juices and smoothies) or more heavily processed (for example, quick oats versus steel-cut oats) digest more quickly, says Allidina. This can result in a faster, higher rise in blood glucose.

Portion size also plays a role, as a larger serving of carbohydrates delivers more glucose to your bloodstream. “Glycemic response isn’t just about the food. It’s also about the amount,” she says.

Lastly, each person’s individual biology and lifestyle, including activity level, sleep, and stress, can influence how the body responds to food. This makes your blood sugar response unique to you.

Individual responses to foods vary, but some “healthy” choices are more likely to cause a rise in blood sugar than others:

• Smoothies and Açaí Bowls Blending breaks down the fiber, allowing glucose to hit your bloodstream faster, says Allidina. It’s also easy to fit a lot of fruit into one serving. Although fruit is packed with nutrients, extra-large portions can lead to blood sugar spikes.
• Oat Milk Although oat milk has been dubbed a healthy alternative to dairy milk, proceed with caution. “Many oat milks are made from refined oat starch and can raise blood sugar quickly, especially when used generously in coffee or lattes,” she says.
• Grain Bowls Whole grains are rich in vitamins, minerals, and fiber, which generally makes them a smart carb choice.

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  But eating large portions without balancing it with protein and healthy fat can increase a meal’s glycemic load and contribute to blood sugar spikes, says Allidina.
• Oatmeal Oatmeal is linked to a lower risk of type 2 diabetes.

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   A large bowl of oatmeal can deliver a high carb load, though, if it’s not paired with protein and healthy fat, she says.
• Juices Unlike smoothies, juices have most of the fiber removed. As a result, “Blood sugar rises faster than when you eat the same food whole and chew it,” says Allidina.
• Dried Fruit Dried apple slices, apricots, banana chips, dates, and other fruits count as a fruit serving.

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   But portion sizes are easy to overshoot, which can increase your body’s glycemic response.

The healthy foods above are not off limits. Making small adjustments to how you eat carbohydrates can help your body handle them more effectively and support steadier blood sugar levels. Start with these tips:

• Pair carbs with protein and healthy fat. This helps slow down digestion and the absorption of glucose into your bloodstream. For example, add Greek yogurt to oatmeal; make a smoothie with protein-rich milk, chia seeds, or hemp seeds; and add chicken, salmon, or tofu to a grain and veggie bowl, says Alladina.
• Keep portions reasonable. If your blood sugar spikes after a meal, reduce the portion of carbohydrates, she advises. Add more nonstarchy vegetables or lean protein instead.
• Choose solid carbs over liquids. “Liquid carbs tend to raise blood sugar faster than solid foods,” says Allidina. Try eating whole fruit instead of drinking juice, or enjoy smoothies alongside a meal, rather than alone, she suggests.
• Eat your vegetables first. Veggies are packed with fiber, which helps slow down digestion. Research shows eating vegetables before carbohydrates can lower postmeal blood glucose levels.

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• Time carb intake wisely. Insulin sensitivity is higher earlier in the day.

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  As a result, your body may be able to handle carbs more efficiently at breakfast than at lunch or dinner.
• Move your body. Research shows that taking a 10-minute walk after you eat can help bring down postmeal blood sugar.

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• Consider other factors. Nonfood factors, such as poor sleep, stress, and even sunburn, can raise blood sugar levels unpredictably.

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   Take these factors into consideration when assessing blood sugar response.

• Even nutrient-rich foods, such as smoothies and grain bowls, can cause noticeable blood sugar spikes.
• How these foods are processed, prepared, and portioned can make a difference in your body’s response.
• Pairing carbohydrates with proteins and healthy fats, keeping portions balanced, and enjoying high-carb foods earlier in the day are all strategies that can help you manage your blood sugar while still enjoying the nutritious foods you love.