] Findings published online this week by the Proceedings of
] the National Academy of Sciences indicate that increasing
] leptin levels in the body can fundamentally change the
] nature of fat cells -- from idle storage containers to
] fat-burning machines. [ Next month : excess leptin causes brain tumors, based on new study. -k] Science & Technology at Scientific American.com: Hormone Transforms Fat Cells from Foes to Friends, Rat Study Suggests | 
