Possible Clues:

• The pub in the heavens will make one thin
• Super thin
• Perhaps one might get pie there in the sky, but it certainly won't make you fat (6)
• Thin as a rail
• Lean's film that's extremely nasty
• Opposite of fat
• Pejoratively thin
• With 8-Down, swims without a suit
• Gossip, slangily
• Where there's pie in the sky it's not a bit thick