Okay, the grossfood challenge from Caramoan had five rounds...
Round 1: 6 players have to eat 2 Beetle Larvae; Andrea, Eddie and Malcolm advance to Round 3.
Round 2: 6 players have to eat 2 Beetle Larvae; Cochran, Michael and Phillip advance to Round 3.
Round 3: 6 players have to eat shipworms; Cochran, Malcolm and Eddie advance to Round 4.
Round 4: 3 players have to eat Balut; Cochran and Malcolm advance to Round 5.
Round 5 2 players have to eat Pig Brains; Cochran wins Immunity.

I believe this season will run similarly.
Round1: 5 players have to eat mealworms; Tyson, Monica and Katie/Vytas advance to round 3.
Round 2: 5 players have to eat mealworms; Hayden, Gervase and Caleb advance to Round 3.
Round 3: 6 players (Caleb, Gervase, Hayden, Tyson, Monica and Katie/Vytas) have to eat Pig Intestine; Gervase, Monica and Immunity Winner advance to round 4.
Round 4: Gervase, Monica and Immunity Winner eat Witchetty Grub;
Leaving 2 to battle it out in round 5.

Round 3 is Pig Intestine because the difference in distance between Caleb and Gervase from the previous round...

and the distance Caleb is from Hayden in the later round.

The difference between 5 players at the table and 6 players at the table.

Then the difference in distance Gervase is from Monica in an even later round.(Witchetty Grub)