If he's telling the truth, why wouldn't he prove the naysayers wrong?
It would be a pretty big victory against those dirty dang Kiwis if he actually was losing weight and proved it.
Do you realize that if he did that we might have to see a pic of his feet.How hard is it to just step on a scale and snap a picture of his weight? He could just do that and leave a picture of something to confirm his identity, like his fake Mao book, his maps, or his bondage gear.
Phil may be telling us the truth about his weight as far as he knows. Remember that towel rack bit from The Simpsons?
That could also explain the lack of footage of him weighing himself.