I can say from my personal experience that I lost 7 kg (14 pounds) in the first 7 weeks on supplements. I am not only taking resveratrol, but also curcumin, and I eat more fruits and vegetables than before. And I try to avoid gluten/wheat. However, the number of calories I eat and the amount of exercise I do remain (more or less) constant, so I believe the effect is mostly due to resveratrol and curcumin.
The weight seem to have stabilized at a level which is probably rather optimal for me - though I could probably loose another couple of kilos to have the right weight.
Agreed, the induced weight loss does level off. Im wondering if the effects are similar with people that dont exercise. I think that exercise maximizes Resveratrols effects.