Not always. Cabin bookings in every category except Classic Monohull include a Host and half-board, meaning six breakfasts, six lunches and two dinners cooked on board, with the food included. Classic Monohull cabins and full yacht bookings don't include food. Full yacht bookings can add a Host, but the Host's fee doesn't cover the food, so you'll still need to provision the yacht.
For how food, drinks and provisioning work on each type of booking, see Is food and drink included?
