The Akimichi Clan originate from the forests of Hi No Kuni, where they were once viewed as a nuisance by the Nara because of their overhunting of the land. Eventually they were brought together by external threats and later joined in on the founding of Konoha. After the defeat of Konoha there were very few Akimichi left, and because of their calorie needs they often had trouble fitting in with society. Those Akimichi that didn't turn to banditry wound up working in various shinobi villages, where their heritage struggles to continue.
Hijutsu
Calorie Control Akimichi are able to convert calories into energy which can be used to fuel their hijutsu techniques (but not others). Akimichi can expand their bodies into larger forms, starting with brief partial growths at lower levels and eventually leading up to maintaining gigantic sizes. Masters of Akimichi hijutsu can convert their calories into pure chakra with the assistance of pills, this grants them a powerful chakra cloak that can be used to create gusts of chakra and enhancements to strength. This however will leave the Akimichi very thin, and it will take at least twelve buffets to repair it.