Rats that are not deprived of water, or that are overhydrated artificially, drink sweet solutions with avidity. We show that intake of sweet solutions is sensitive to nutritional status, suggesting that the rats are treating the solutions as liquid diets and “eating” rather than drinking them. First, when rats are force-fed to mild obesity, intake of dilute and concentrated saccharin and carbohydrate solutions is progressively reduced. Secondly, when weight loss is forced by restricted feeding, intake of saccharin and dilute carbohydrate is elevated, but intake of concentrated carbohydrate solutions is not. Perhaps the postingestive effects of concentrated sugar solutions set a limit on ingestion, so that intake can be driven below that limit as weight is gained, but cannot rise above it as weight is lost.