I think that's supposed to be a parody of the Heath Shake, not health shake. When was working at my college's cafeteria for a while, we used Heath Bars in some of our shakes.
I drew this America as a present for a friend. When I went looking for food-related material, I found a drink with 2300 Calories (2300kcal) and burst out laughing. Only in America! (Checking out the general calories, there were some extra numbers written on it considering the quantity.) But I couldn't help thinking that someone could eat that much in a single day. For some reason junk food makes you want to gorge yourself. And, this art got daily ranking, Thank you!
(Pixiv tag: 6450 x 365)
EDIT: Thanks for tagging! 6450 Calories is about three days worth of calories for an adult male. A woman would still have some left over. If you kept it up for 365 days, ending up with metabolic syndrome would be no surprise.