The O.C.B. rule
The Old Country Buffet by my house has an abundance of food options, almost all of which are either too sweet, salty or bland to be worth consumption.
In fact, of the all-you-can-eat establishments I've been too in the past, I don't think I've once found anything worth the caloric withdrawal. Smorgasbord offerings rarely do.
Which highlights an important point: if it's not worth it, don't eat it (or buy it).
Save it (your appetite, your money, your time) for something that is.
Give yourself a favor and default to higher standards. Trade the crappy ice cream for out of this world good(!) instead.