You may have heard of the 5:2 diet: two days of eating very little with five days of eating normally. Well this is even easier. Two days a week you skip breakfast but otherwise you eat normally. Nothing to record and it requires very minimal effort.
Made by James Porter.
I'm not aware of anything supporting this approach. But I am a Dr. (of Economics and Complexity Science) so you should totally trust me. More seriously bear in mind that as nobody will get rich selling you products for intermittent fasting there is little incentive for the research to take place to 'prove' it works. Unlike other 'health' interventions.