I have been following the rule the way @ms.sss has, I have always drank up till the meal but afterwards, I've been hardcore about not drinking till at the very least 30 minutes, but usually go much longer, until I feel my stomach has emptied. The times I have drank after 30 minutes, I feel hungry much sooner so I wait as long as possible. It applies to snacks and meals, any time you have anything other than a liquid, including soup.