So, how does this invalidate the researcher's claims? I'm not sure how they support corporate propaganda. He made one of the most important discoveries regarding leptin and its role in fat gain/loss. One of the things researchers have known is that, when people diet, their metabolism crashes like a rock--most people's. Some people's does not. In a Minnosota study, for instance, people's metabolisms crashed by 25% after four weeks of dieting. If they maintained on 2800 cals a day and cut back to 2000 in order to lose weight, in a month, that 2000 cals is merely going to maintain their weight, even though they'd only lost 1% of their body weight each week. That 1% figure is pretty well known as what someone can typically lose (fat-wise). It's really very difficult to lose more than that and this has to do with the way leptin production upregulates or downregulates in response to caloric intake/expenditure.
Kelley