I do know for a fact, and this is from experience, you don't have to exercise or lift to lose weight.
A couple of years ago I had jaw surgery and had to get my mouth wired shut. For 30 days, I was on a liquid diet and I lost 20 lbs. And during those 30 days I did nothing but sleep, play xbox360, sleep, drink fatning liquidfied food, watch dvd's, and more sleep.
Here's a sample of stuff I drank:
melted ice cream (more like a milk shake without the milk)
thinned mash potatoes with lots of sour cream and milk
protein shakes (vanilla, chocolate, cookies-n-cream)
bean soup with sour cream
tomatoe soup with sour cream
yogurt thinned with whole milk
grape juice
whole milk with almond extract and sugar
I was on a 2500 - 3000 calorie diet, with no exercise, and I still lost weight. I went from 170 to 150 lbs and now I'm at 160.
Liquid diets work!