"I have read that you shouldn't put food in checked luggage because it means your bags will more likely be searched. It may be something new with new security reasons since 2001."
Actually, the caution is in regard to DENSE foods; things that are thick and solid, such as slabs of chocolate or large pieces of cured meat, like a ham or a salami. The reason for that is that the profile they render on an x-ray is similar to that of plastic explosives.
Other foods that should not be packed in checked baggage include any kind of perishables (fresh fruits and veggies, dairy, frozen meats) because if the bag gets lost, the food may rot and ruin everything else in the bag with the smell. You should also not pack liquids in thin bags or glass bottles, because if the container breaks, everything else is ruined. (Especially other people's things, which is what the airline is most concerned about.) Of course, "discouraged" only applies to US domestic flights re: perishables; they are flat-out forbidden for passenger import into the US on intl. flights.
Generally speaking, packaged dry foods such as cereals, snacks, powder mixes, dried fruits, etc. are going to be just fine if they are still sealed, and they normally will not set off any add'l security.
(BTW, you would be AMAZED at the number of people who fly w/ an entire salami. I've seen them more times than I can count. They are allowed on domestic flights as carryon, but you can't bring them from overseas. Customs always ends up confiscating a ton of salami brought in from Europe.)