Diets Don't Work, but why?

http://commonhealth.wbur.org/2015/05/why-diets-dont-work

“Studies show that willpower, the thing we all blame ourselves for not having enough of, is in many ways a mythical quality and certainly not something that can be relied upon for weight loss.”

'Turns out, a good bit of Mann’s plan calls for external changes, like using smaller plates and taking smaller portions, a la Brian Wansink’s Mindless Eating. '

I read this with a smug look on my face..