We go by the guidelines given in Leviticus 11.
If a mammal does not have split hoof and does not chew cud, it is considered unclean. This eliminates most mammals. Leviticus lists several unclean mammals; camel, hare, badger and pig.
Fish that does not have scales or fins is considered unclean.
Leviticus lists a number of unclean birds that are predators and scavengers. Included in the unclean list are water fowl with webbed feet (swan, pelican; verse 11), and so most Adventists do not eat duck or geese because these are the same species as the unclean birds mentioned, and because Genesis says they were created according to their kind (Genesis 1:24-25).
Insects listed include locust, cricket and grasshopper, but all others are unclean.
The easiest way to break it down at the grocery store is this:
Yes:
- Beef, venison, lamb and goat
- Chicken, turkey
- Tuna, salmon, mackerel, cod, halibut, sardines, perch, trout, etc.
- Imitation crab that doesn't have actual crab in it but uses whitefish or the like.
No:
- No pork in any product (they put pork in so many things). Includes lard, which is found in various products, like Jiffy mixes.
- No duck or geese.
- No catfish, crab, shrimp, lobster, crayfish, oysters, shark, swordfish or sturgeon.
Adventist diet varies from one person to the next. Some do not eat dairy or eggs, others do. Some are strict vegan, some are not. Some eat meat, some do not.