It’s really an ‘evolved’ thing. When Huel was launched we sold it as a ‘week’s supply’ (or '‘two week’s supply’, ‘four week’s supply’, etc). Two pouches on 2,000kcal per day = 14,000kcal = 2 bags. We changed this as, of course, most people didn’t have 2,000kcal-worth of Huel per day and instead sold it by the ‘meals’, with the same pouch size.
We’ve had this standard pouch from day one and, sure, there’s a bit of room to fill a bit more, but, due to the force when the machine puts Huel into the pouches, there needs to be headroom*. We’re looking at new pouch material (to solve the sustainability bit) and too large would mean they could be more susceptible to splitting. Plus, they wouldn’t fit comfortably into most people’s cupboards, possibly. So 17 servings has come from this. 20 servings would definitely mean a larger pouch.
17 servings is fair to question though. but why 20? There’s an arguament that 14 would make more sense.
*Julian filmed me on this machine once; I was useless and got Huel all over the floor and myself! 