From the Can I have guide linked in my signature below: (Plus you have no fat in this)
Smoothies: We’d rather you didn’t
This is a very popular question, with a very unpopular answer. Smoothies (generally made using lots of fruit) are technically compliant on your Whole30, but we strongly recommend against it. Food that you drink sends different satiety signals to your brain than food that you chew. So when you drink your meal, your brain isn’t getting the feedback it needs to tell your body that it’s had enough of what it needs. Plus, smoothies are generally really fruit-heavy, and starting your day off with a liquid sugar-bomb sets you up for cravings, hunger, and volatile energy levels throughout the day. In summary, we’d rather you just eat the food, and skip the smoothie.