(100% opinion with no scientific backing here)
Humans are programmed to be energy conservative, to find the path to their goals (historically, food, shelter, reproduction…) that provides the least resistance possible. That’s why fad diets are so popular. What requires more mental effort, making a one-time decision to cut out entire categories of foods, or making an effort day after day to make sure the majority of your diet comes from a variety of (I hate this term, but for simplicity…) whole food sources? Fad diets trigger something deep inside us that makes them feel like they will get us to what we desire with less effort.
It’s the same reason so many guys program hop like crazy. Progress stalls or regresses, and rather than admitting that it’s related to the shit decisions they make the other 23 hours in the day that they aren’t training, they convince themselves that it’s the exercise selection, reps, sets, percentages, etc., that’s the reason they aren’t progressing. All they have to do is find that magic combination and boom, a new PR is sure to come!
Just go to any major general public facing website and look at the ads. “One weird trick to melt belly fat”, “The new superfood big pharma doesn’t want you to know about”. Shit like that is all over the place BECAUSE IT WORKS. We want so badly to believe all our hopes and dreams are just one small change away, because the alternative is admitting that it’s actually going to be a long, difficult road that requires a lot of discipline and consistent effort on our part.