According to Healthline, fruit juice is “inappropriate” for the Keto diet.
But there are a few exceptions including lemon and lime juices, which are low in carbs but full of flavour.
A blend of apple, spinach, kale, and collard with lemon juice has around 25 grams of carbs per serving, which is more than the total daily carb limit for the keto diet.
It is worth noting that while added sugars (found in processed foods and fizzy drinks) are bad news, sugar from whole fruit is considered natural sugar.
source: express.co.uk