That is no longer the current opinion. It was based on a single study that has been discredited after nobody has been able to repeat its results even after decades of trying.What we call willpower is a finite force. This is documented as 'ego depletion',
That I totally agree with. The changes we make have to carry their own immediate awards or they won't stick. Exercise you genuinely enjoy. Healthy food that tastes great and doesn't weigh you down. Maybe only small changes at first, stuff that doesn't scare our habit-loving brains.therefore dissmissing it as weak willed is missing the point.
But maybe the problem is that we are tapping into those will power reserves and they are depleted. Maybe the way out is finding some way to jump from willpower to something else. The thing is how.