We schedule a 12 minute break after each hour of play. It sounds excessive but...
All times approximate
First break, 8pm: Players that arrived late for dinner can load up on food. Since most guests also bring a dish to pass, early arrivals usually miss the later arrivals dishes, so this gives them another go.
Nobody loses weight at Zombie Poker night.
Second break, 9:12pm: Dessert time. We usually have 4-6 desserts available, so even if you had some dessert earlier, you can find something completely different. I told you, there is no weight loss here. Main course and spoilable foods are put into the fridge. Snack trays, crock-pot foods, and chips remain out as well.
Third break, 10:24pm: The peak in player eliminations occurs between 2nd and 3rd break. Players that don't want to hang around usually wait until 3rd break before heading out. This allows them a chance to say their goodbyes to everyone (our poker room is difficult to maneuver in once everyone is seated).
Fourth break, 11:36pm: This break is primarily a smoker's break and color-up. The field is reduced to the final few and other than the color-up, this break is optional. Once everyone returns, cards are in the air again, but more times than not, a smoker will smoke, a drinker will pee, and all will be ready to go fairly quickly.
I will add that our group is extremely social and players like to talk away from the tables. I will also add that my room is crowded with 2 tables, and getting a drink or making a restroom run is difficult (and from some seats impossible) unless people clear out.