Sure a V-diet will do it. But why do you need a V-diet to do it ?
It's not the V-diet itself that's doing it - i.e lose a substantial amount of fat in 28 days - IMO.
Using the example in your link.......simply slashing your caloric intake to well below your BMR ( as suggested for the 193 lb. person ) is bound to result in a substantial amount of fat in 28 days....whether it's from shakes or from food. Starvation mode dieting works - shakes or not. But again, it not whether it works or not ...that's not the issue....steroids work too after all !
My question to you is....
" Why does someone who is an average gym rat - not an elite athlete, not a bodybuilder or cover model, not someone who is morbidly obese - have to resort to an " an extreme diet " ?