Lol, you're not being stupid - I thought the exact same thing. I nearly bought some but as there is a fruit in the title and the leaf is from a fruit I would say no... but it is something to check on. If I find out before you I shall let you know
I've drunk fruit teas all the way through with, seemingly, little detriment to the diet......don't get too hung up, just don't have milk in anything! I've also drunk diet coke and used Robinsons low calorie squashes. At least it helps you get the water down, I'd never have managed it otherwise!