Earlier quoted context omitted.
Eat less calories than you use each day. (fullstop!) While true, that statement is useless. It doesn't take into account the effect insulin has on the ability one has to actually take in those fewer calories. It also doesn't take into account metabolic pathways that allow one to eat more of certain kinds of foods than others. The scientific literature is pretty clear (once you filter out the government propaganda tha…
You're still making it way too complicated. If I put 10 gallons into my tank every day, but use 11 gallons daily.. I'm "using up" gas. That's all that matters. Of course, there are many, many, many tweaks to be made, but for the majority of people, who need to lose a massive amount of weight, if they eat less calories than they use, they will lose weight. End.
This still doesn't make things terribly complex, and getting the basics down will help a lot.