By Theresa Hennig RDN, LD
Food 4 Success, LLC Dietitian

A trip to the local smoothie shop may seem like a healthy choice, offering a blend of fiber- and antioxidant-rich fruits and veggies, along with additions like Greek yogurt and protein powder. However, it’s crucial not to be deceived by marketing tactics. Many smoothies can pose challenges for blood sugar levels. While fruits and vegetables are healthy on their own, blending large quantities can result in a significant sugar intake, often accompanied by reduced fiber. Combined with sweetened ingredients like frozen yogurt and honey, some smoothies rival ice cream sundaes in sugar content.

But don’t despair; you can still enjoy a smoothie without compromising blood sugar levels. By being selective about the menu and ingredients, you can have a convenient, health-conscious meal or snack that keeps your blood sugar stable.

While you wouldn’t consume over five servings of fruit at once, many smoothies pack that amount into one portion, leading to a sugar overload. For instance, a medium 22-ounce Watermelon Breeze smoothie at Jamba Juice contains a staggering 85 grams of sugar, equal to two 12-ounce soda cans!

Fruits contain two simple sugars: glucose and fructose. Glucose is your bloodstream’s primary sugar. A large dose can cause rapid blood sugar spikes and crashes, which can lead to insulin resistance and diabetes. Fructose is metabolized in the liver and excessive intake can cause fat accumulation in the liver, increasing the risk of insulin resistance and metabolic syndrome. Most health issues from fructose stem from artificial high-fructose corn syrup in processed foods.

Whole fruits and veggies have a milder impact on blood glucose due to fiber, which slows glucose absorption. In fact, more low-glycemic whole fruits may reduce diabetes risk, possibly improving insulin sensitivity.

Smoothies’ issue is that blending destroys insoluble fiber, causing a quick blood sugar rise. Some fruits naturally have more sugar, especially tropical fruits often used in smoothies. For example, mango has 23 grams of sugar per cup, while a large banana has 17, compared to 5 grams in a cup of raspberries.

Additionally, some ingredients in smoothies can elevate blood sugar levels, like frozen yogurt, honey, agave, or sweetened protein powder. When combined with sugary liquids like fruit juice or sweetened nut milk, the smoothie’s sugar content skyrockets.

Most smoothie shops offer a build-your-own option, allowing a balanced drink. The key is the right mix of fruits, veggies, fats, and protein.

8 Steps to a Healthier Smoothie Choice

  1. Prioritize Veggies: Focus on vegetables, aiming for a veggie-heavy and fruit-light blend. Ask for extra vegetables, ensuring your smoothie has a greenish or brownish hue. Leafy greens like spinach and kale, rich in magnesium, help maintain stable blood sugar levels.

  2. Choose Lower-Sugar Fruits: Tropical fruits like mangoes, bananas, and pineapples have more sugar. Opt for raspberries (5 grams per cup), strawberries (7 grams per cup), blackberries (7 grams per cup), and blueberries (10 grams per cup). Kiwi, with only 6 grams per fruit, is another smart option. Use fruit as a condiment and add a small amount.

  3. Incorporate Healthy Fats: Add heart-healthy fats for satiety and metabolic health. Polyunsaturated fats support insulin secretion. Include almond butter (9 grams of fat per tablespoon), peanut butter (8 grams of fat per tablespoon), or ground flaxseed (3 grams of fat per tablespoon). These provide some protein. Coconut oil (11.5 grams of fat per tablespoon adds a hint of sweetness without sugar.)

  4. Include Protein Sources: Protein curbs hunger without blood sugar spikes and slows glucose release. Consider plain, unsweetened nonfat Greek yogurt (23 grams of protein per cup), nut butters, flaxseed, and chia seeds. If more protein is desired, use unsweetened protein powder.)

  5. Opt for Water or Unsweetened Milk: Many shops use fruit juice, increasing sugar without fiber. Research shows moderate fruit juice consumption can raise diabetes risk due to its high glycemic load and rapid digestion. Blend with water, coconut water, milk, or unsweetened non-dairy milk. Ensure plant-based milk lacks added sugars.

  6. Achieve Creaminess Without Added Sugars: Some smoothies use sherbet, frozen yogurt, or ice cream for creaminess. Even two frozen bananas can contribute over 32 grams of sugar. Request frozen berries, raw nuts, or half a banana for thickness. For a healthier option, choose protein-rich Greek yogurt or request avocado, rich in healthy fats.

  7. Avoid Sugary Syrups: Ingredients like honey, agave, maple syrup, or date syrup introduce sugar without significant nutrients. Add flavor without sugar using vanilla bean paste, cocoa powder, or cinnamon.

  8. Control Portion Size: Many smoothies are large, with some reaching 32 ounces (four cups). Liquids are consumed quickly, leading to excess calories and sugar. Divide your smoothie into two containers to save for later or share!

Smoothies can be a tasty and easy way to pack in nutrition into your day, but knowledge is power. Now that you are smoothie-savvy, you can be assured you are making a great choice!