The Hawthorne effect suggests that meticulous food logging can be an effective dietary intervention.

“The Hawthorne effect is is basically an effect that says if a person is watching you you will change your behavior so anybody who has tried to fastidiously log what they eat every day which I've done many people have done this there's no question you change your behavior just by logging what you eat you will change what you eat how much more will you do it when you know someone is going to look at it unbelievably so in fact you could make a case that one of the most efficacious dietary interventions known to man is having somebody watch what you eat every meal”