when you're just starting out it mightn't help with the boosting metabolism aspect but it can certainly help psychologically. usually in the past when i started eating less calories i would be fine for about a month and then i'd start wanting foods that i'd been avoiding. i reckon that's why a lot of people who try to lose weight will fail when trying to "diet". there's only so long a regular person can go with such a drastic change of lifestyle. so instead it's better to change your diet not quite so drastically and not completely cut out all those foods we love and ate too much of in the past. that is of course from a losing weight point of view.
for me it's like, say i'm dying for a pizza i can just say to myself "no, wait til saturday" and it makes the world a much nicer place