Possible Clues:

• Fatty stuff I had -- fleshy part at the front
• Fatty stuff in fleshy part I had reduced
• Fat, for one
• Mark the two destined never to meet?
• Fat detective in a hat
• Animal oil
• Mouth on fish reveals oily substance
• Group of chemicals found in bodily tissues
• Triglyceride, e.g
• Compound such as a fat, oil or wax