No.021
Are Smoothies Healthy? What Makes a Blend Good for You
A smoothie is as healthy as what goes into the blender and how much of it you drink. A few simple rules turn it from a sugar hit into a decent meal or snack.
- Posted
- Minutes needed
- 4 min
- Corner
- Nutrition
Smoothies can be healthy, but it depends on three things: what goes in, how big the glass is and whether it replaces something or is drunk on top of a full meal. A homemade blend with vegetables, a modest amount of fruit, a source of protein and a little fat is a convenient, filling option. A large bottle built on juice, sweetened yogurt and syrup is closer to a dessert. Most of the difference comes down to ingredients you control.
Smoothie, juice and whole fruit
Blending keeps the fiber that juicing throws away, so a smoothie is usually more filling than juice. But blending also breaks open the fruit's cell walls, so the natural sugars are released more freely than when you chew an apple. That is why some dietary guidelines count the sugar in juices and blended fruit as "free" sugar, in the same bucket as sugar stirred into food, and suggest keeping portions small.
| Whole fruit | Smoothie | Juice | |
|---|---|---|---|
| Fiber | All of it, intact | Kept, but broken down | Mostly removed |
| How filling | Most | Moderate to high, depending on ingredients | Least |
| Easy to overdo | Hard; chewing slows you down | Fairly easy | Very easy |
| Room for protein and fat | Only alongside | Built in | Not really |
Whole fruit stays the best everyday choice. A smoothie earns its place when it brings in foods you might not otherwise eat, such as greens, seeds or yogurt.
What makes a smoothie healthier
- Vegetables first. Spinach, kale, cucumber, cooked and cooled cauliflower or zucchini add volume with little sugar and barely change the taste.
- A measured handful of fruit. Frozen berries or half a banana give sweetness and body. You do not need three kinds.
- Protein. Plain yogurt, milk, soy milk, silken tofu or nut butter make the drink more satisfying. Our guide to which fruit has the most protein shows why fruit alone will not cover this.
- Some fat and fiber. Oats, chia seeds, ground flaxseed or avocado slow things down so energy lasts.
- Unsweetened liquid. Water, milk or an unsweetened plant drink rather than juice.
For tested ratios and combinations, see our step-by-step guide on making a smoothie that actually fills you up.
What turns one into a sugar drink
- Fruit juice or sweetened plant milk as the base.
- Honey, syrup, sweetened yogurt, frozen yogurt or ice cream.
- Very large portions, especially from cafés and chains.
- Several fruits and no vegetables, protein or fat.
- Sipping one slowly over a whole morning, which keeps teeth bathed in sugar and acid.
Reading the label on bottled smoothies
- Check the serving size. One bottle may contain two servings, which doubles the numbers on the panel.
- Look at the ingredient order. If apple or grape juice comes first, the drink is mostly juice.
- Find the added sugar line. On US labels, "added sugars" are listed separately from total sugars.
- Look for protein and fiber. A drink with almost none of either is unlikely to keep you full.
Can a smoothie replace a meal?
It can, if it is built like a meal: vegetables, protein, a source of fat and some slow carbohydrate such as oats. A fruit-only blend will usually leave you hungry within an hour or two. Many people find a meal smoothie works best a few times a week rather than every day, alongside regular, chewable food. Prepared freezer packs, like the ones in our guide on how to start meal prepping, make the balanced version as quick as the sugary one.
Who should take more care
People managing diabetes or blood sugar, anyone on a potassium-restricted diet for kidney disease, and those taking medicines that interact with certain foods, such as some blood thinners and leafy greens, should ask their doctor or a registered dietitian how smoothies fit their plan. The same goes for anyone using drinks to replace meals for weight loss over a long period.
Quick answers
Are green smoothies healthier?
Usually, because vegetables replace some of the fruit. Taste can be an issue at first; start with mild greens such as spinach and a squeeze of lemon.
Do smoothies help with weight loss?
They can help if they replace a less nourishing meal and keep you full. Added on top of usual meals, they add energy instead.
Should I add protein powder?
It is optional. Yogurt, milk, soy milk and nut butter cover most needs for an ordinary snack. If you do use a powder, choose one without much added sugar, follow the serving size on the tub and remember that supplements are less tightly regulated than food.
Is it better to drink it straight away?
Fresh tastes best, and some vitamins slowly break down. A smoothie kept covered in the fridge is fine for later the same day; give it a shake first.
Where we stand
Our guides inform, your clinician decides
We write to make everyday health topics easier to understand and easier to act on in small, safe ways. We are not trained clinicians, and an article can never know your history, your medicines or what a professional would notice in person.
If something you read here sits uneasily with advice you have been given face to face, follow the advice of the person who has actually seen you.
Sunniva, Ansgar, Briallen and Halvard