OMAD Fasting/Intermittent Fasting.
Fasting is when a person willingly abstains from food and/or drinks for a decided amount of time. Attached is an article further explaining Intermittent Fasting.
Intermittent fasting: Surprising update
OMAD stand for one meal a day. It is a more extreme form of fasting. An example article examining this is listed below.
https://www.google.com/amp/s/m.timesofindia.com/life-style/health-fitness/diet/weight-loss-three-different-types-of-omad-diet/amp_articleshow/70817454.cms