8 Steps to a Delicious and Nutritious Smoothie That Actually Keeps You Full
Smoothies are an excellent way to get plenty of fruits, vegetables, fluids, and nutrients into your body, however, not all smoothies are created equally! If you aren't strategic about what you put into your smoothie, you could end up spiking your blood sugar, leaving yourself feeling shaky and hungry an hour or 2 later, or going significantly over your energy requirements for the day. Many people will load up a smoothie with fruit and fruit juice without adding any protein, fat, or extra fiber sources to slow down the absorption of sugar into the blood stream. Others tend to pack in spoonfuls of nut butters and homemade nut milks to the point of excess, causing their smoothie to contain more energy than their body requires from a meal. While all of these ingredients are generally healthy, even too much of a healthy thing can be problematic.
In addition, if you take a look through the smoothie menus of popular juice bars, you may be surprised to find that many of the smoothies they offer contain more sugar and as much fat as a bowl of ice cream. In fact, Jamba Juice's "healthy sounding" medium-sized Greens n' Ginger smoothie contains a whopping 90 grams of sugar! For reference, Ben & Jerry's Phish Food Ice Cream contains 28 grams of sugar per serving... And that's one of the better ones; the chains' Peanut Butter Moo'd smoothie contains 770 calories, 20 grams of fat, and 109 grams of sugar--yikes! Even Juice Press has no shortage of sugar-laden, caloric smoothies on their menu. Their Almond Buttercup smoothie contains a whopping 35 grams of sugar and 33 grams of fat per serving thanks to the addition of agave (a sweetener that sounds healthy but is no better for you than any other form of sugar), lots of banana, high-fat homemade almond milk, and a generous amount of almond butter. Luckily, lower-sugar, nutrient-dense smoothies that won't tip you significantly over your daily energy requirements aren't difficult to make, and by following these simple guidelines, you'll be whipping up satisfying, delicious and nutritious smoothies in no time!
1. Use veggies as your base
Non-starchy frozen vegetables are nutrient-dense, but not energy-dense and therefore they are great for adding bulk to your smoothie, extra fiber to slow down the absorption of fruit sugar into your bloodstream, and plenty of additional vitamins, minerals, and antioxidants. 3 vegetables that I like to use as smoothie bases to add bulk and creaminess rather than ice cubes or extra frozen fruit are: frozen riced cauliflower, frozen riced broccoli, or chopped frozen zucchini. I also save kale and broccoli stems that I would otherwise throw out, chop them up, freeze them, and add those as part of my vegetable base. It's a win-win because you will be cutting back on food waste all while increasing the nutrient density of your smoothies and saving money on additional ingredients. My favorite base is the frozen riced cauliflower because it’s colorless, essentially tasteless, and odorless when combined with the other ingredients below, plus it makes smoothies incredibly thick and creamy. Cauliflower is also a good source of vitamin C, vitamin K, choline, folate, potassium, and vitamin B6. I generally use about 1/2 a cup to give smoothies that thick, frozen consistency.
2. Add greens
Smoothies are an excellent opportunity to sneak an extra serving of leafy greens into your day. Most people don't eat nearly enough leafy greens—they are low in energy density (calories), high in fiber (majorly lacking in most peoples' diets), and filled with important nutrients like magnesium which is needed for over 300 biochemical reactions in the body. Leafy greens also contain folate, vitamin K, calcium, antioxidants, and much more. If you still aren't convinced that you should be eating more leafy greens for your body, then eat them for the sake of your brain--A recent prospective study published in the journal Neurology found that out of 960 non-demented adults, those who ate the most servings of leafy greens each day (1.3 servings on average) had half the rate of cognitive decline after 5 years compared to those who consumed the fewest servings of leafy greens per day. Other studies have suggested that the observed positive association between preserved cognition and leafy green consumption is even stronger when individuals consume cruciferous leafy greens like kale and arugula. I like to add at least 1 cup of kale, spinach, collard greens, micro greens, or whatever other leafy greens I have lying around to my smoothies. While greens may lend an earthy hue to your smoothie, I assure you that their taste will not be detectable after adding some fruit and other flavorful ingredients!
3. Choose a protein
In order for a smoothie to function as a meal, it should have some sort of protein source. Protein is not only needed for tissue repair, building and maintaining lean muscle mass, producing hormones, enzymes, and more, but it is also a vital nutrient for increasing satiety and suppressing hunger. The presence of protein in the digestive tract stimulates the release of a hormone called peptide YY which suppresses hunger through multiple mechanisms. Protein intake also causes a decrease in the release of ghrelin, also known as the "I'm hungry hormone" because it promotes appetite as well as fat storage. In addition, protein requires more energy to digest and takes longer to digest compared to carbohydrates. When you pair protein with carbohydrates such as those found in fruits added to a smoothie, you will help to slow the absorption of the fruit sugar into your bloodstream, leaving you feeling fuller for longer and without blood sugar surges that often lead to that unpleasant shaky feeling later on as your blood sugar dips again.
The protein you add to your smoothie doesn't necessarily have to be protein powder, although that certainly is an option. When it comes to protein powders, I like to opt for ones with minimal ingredient lists, and I am careful to do my research on the brand before I buy because protein powders can be subject to heavy metal contamination during processing. For this reason, I try to look for brands with third party quality inspection certifications.
Non-protein powder protein sources include unsweetened peanut powder or unsweetened almond powder which is essentially dehydrated peanuts and almonds in powder form. It contains little fat or carbohydrate, and 5-6 grams of protein in 2 tablespoons, making it a more concentrated and isolated protein source compared to regular nut butters which are also high in fat. This isn't a bad thing (see step 4), but I view nut butters primarily as fat sources rather than protein sources and add those separately in slightly smaller quantities. Other great protein sources include: plain Greek or Skyr yogurt, unsweetened soy milk, or dairy milk (ideally grass-fed when possible). Other dairy-free milks such as almond, coconut, or cashew milk are not significant sources of protein, but they can still serve as your liquid for the smoothie (see step 6).
The amount of extra protein that you should add to your smoothie depends on your unique needs which will vary based on age, activity level, body size, sex, medical conditions, medications, and more. It can also vary depending on the day and what else you are eating, however 1/2-1 scoop of protein powder, 2 tablespoons of peanut or almond powder, 1/2 cup of plain Greek or Skyr yogurt, or 1 cup of the milks mentioned above are all great places to start. Pay attention to how you feel afterwards and you can experiment with tweaking the amount of protein you add. Remember that other ingredients you add to your smoothie contain protein too (such as nut/seed butters and even vegetables contain a little bit--about 2-3 grams per cup!), so don't feel the need to go too crazy with the protein--just enough to satiate and serve your needs for a meal. After all, when you consume more protein than your body needs, the nitrogen portion is excreted and what remains of the amino acids is converted into glucose to be used for fuel or stored.
4. Select a healthy fat
Ever drink a fruit smoothie and find yourself starving an hour later, as if the smoothie went straight through you? That may be because it was pure carbohydrate and lacked protein or fat to slow down its digestion and absorption! Similarly to proteins, fats slow the speed at which your stomach empties, causing you to feel fuller for longer. When you eat fats, the release of CCK is triggered, another hormone that promotes satiety. That being said, you don't want to get overly zealous with adding tablespoons upon tablespoons of fats as they do contain more than double the amount of energy per gram compared to protein and carbohydrate. A tablespoon or 2 of nut butter, 1/3-1/2 of an avocado, or 2 tablespoons of flax, chia, or hemp seeds are all great sources of heart-healthy mono-unsaturated fats (and some omega-3 fatty acids) to help stabilize your blood sugar, slow the absorption of the fruit sugar in your smoothie, and promote satiety.
5. Add fruit
This is where it can be easy to go overboard by loading up your smoothie with banana, tropical fruits, dates, and more. When it comes to choosing the amount of fruit that you add to your smoothie, it's important to consider how much fruit you would have if you were eating it on its own rather than drinking it. For example, you may not sit down and eat 2 large bananas and 2 cups of pineapple chunks, yet when it's all blended into a smoothie, that amount of fruit is incredibly easy to quickly consume in one sitting. It is also important to consider the type of fruit that you are adding. Tropical fruits like bananas, mango, pineapple, figs, dates, and passionfruit are higher in sugar, as are grapes and cherries, whereas strawberries, blueberries, raspberries, blackberries, and cranberries are very low in sugar and highest in fiber. I am not saying that you should avoid those higher-sugar fruits by any means, as they have many health benefits and add lots of flavor to smoothies, however you may want to be mindful of portion sizes. I like to use a combination of higher and lower-sugar fruit such as 1/2 of a banana and 1/2-1 cup of frozen berries. This way, your smoothie contains a reasonable amount of fruit that is enough to add plenty of sweetness and flavor in addition to fiber and potent antioxidants.
6. Pick a liquid
My favorite liquids to add to smoothies are unsweetened plant-based milks such as almond milk, or if I'm in a pinch, I will add water. I typically avoid using fruit juices or coconut water as the primary liquid in smoothies because they are higher in sugar, lack fiber, and again are more likely to cause blood sugar spikes and increase the energy density of your smoothie without providing much nutritional value. Unsweetened dairy-free milks are also often fortified with calcium and sometimes even with vitamin D, both of which are incredibly important for bone health (be sure to check the label first if this is a concern for you). While I do like the higher-fat homemade-style nut milks (common brands sold in stores include Malk cashew milk, Forager cashew milk, New Barn almond milk, Elmhurst milks, and Two Trees almond milk) for adding to various recipes and coffee, I avoid using these for smoothies if I have already added a fat source such as a nut butter since smoothies require a relatively large amount of liquid to blend. Since fat is twice as energy dense as protein and carbohydrate, adding too many high-fat ingredients (even healthy fats!) can tip the energy density of a smoothie over into excess. If you prefer the higher-fat homemade nut milks as your liquid, then I would recommend mixing them with some water to dilute them a little, or use them without diluting, but then omit your fat source from step 4.
7. Add flavor
Now is time for the fun part--choosing the flavor profile of your smoothie! Peppermint extract or mint leaves, cacao powder, cinnamon, pumpkin spice, freeze dried coffee, and matcha tea powder are all flavorful additions that will give your smoothie some pizazz. One of my favorite combinations is adding a few drops of peppermint extract or fresh mint leaves and a tablespoon of cacao powder to my smoothie for a delicious chocolate mint flavor (it's even better when you top it with cacao nibs!). I also think that spices are extremely under-utilized when it comes to smoothie making. Not only do spices add plenty of flavor, but many also have antioxidant properties among numerous other health benefits including benefiting your gut bacteria for a healthy and more diverse microbiome. You can even get creative and experiment with different kinds that you normally wouldn't think to add to a smoothie including nutmeg, cardamom, ginger, and cloves.
8. Sprinkle on a topping
The act of chewing is satiety-inducing, which is why many people often feel unsatisfied after drinking a smoothie, or they end up hungry shortly after drinking one. By adding a topping to your smoothie, you force yourself to chew, adding more texture and interest to your meal, and increasing your satiety in the process. You will also be subsequently slowing down the speed at which you consume your smoothie since chewing takes extra time. This can help with digestion and increase your satisfaction from the meal. Some great smoothie toppings are a few tablespoons of a high-fiber cereal, a sprinkle of flaxseeds or chia seeds, a tablespoon or 2 of cacao nibs, some crushed nuts, a small handful of oats, or a sprinkling of a low-sugar granola.
To get started, here are links to some of my favorite smoothie recipes: