Looking at the oft quoted diet fail statistics, diets fail 98% percent of the time or 95%, depending on which point in the time line. These figures cause controversy, increasingly so it seems.
It's hard to pinpoint exact attribution to their source Keys or Stunkard. Many find these figures deeply disappointing, finding any mention of it, offensive.
As if it's some kind of libel against WLD, maybe even themselves, for adhering to a set of figures they wouldn't normally touch with a barge pole.
It's an inevitable part of not accepting the truth about dieting. Even then, it typically evades focusing on a real issue, the lack of hard statistical evidence on the efficacy of weight loss dieting. You'd think that it should have been rigourously tested before being recommended as the answer for everybody.
You'd also think that after all this time someone would have bothered to do a long term large scale unbiased study on it.
Set a goal of weight at BMI 25, for those who are fat. As nothing above this is seen as acceptable. Let's not move the goalposts for the professionals eh?
Include plump and slim people, obviously, set them goals accordingly. It maybe important to see if there's any variance between groups.
I'd recommend you start with many, many thousands finding a way to check at least weekly how many people are still in the study. With some provision for re-entering the study if within a certain short period of say a couple of weeks or a month as things like that happen when people are dieting.
Give people the means to say they've had enough and they're okay again, perhaps a small electronic device. Create the ability to record a sample of daily records.
It could be a five, seven or ten year study, with snapshots taken over certain periods.