Actually, I'm pretty sure that side effect isn't even potential - if you don't get it, there might be something wrong elsewhere.
Speaking from experience here, dehydration is a concern not because of drinking less but because the stuff will actually actively dehydrate you, meaning you need to drink more than you normally would.
The appetite loss is not actually caused by the diuretic effects. I'm not 100% on this, but I think it's actually the other way around (something to do with reduced calorie intake and diffusion of sugars).