I don't think Mendenhall was underrated. At the time many
pegged him as a possible future Mr. Olympia.
According to Flex Mag June 2007 he was 255 at the 1991 Nats
at 4 1/2 % bodyfat.
He states that he had a water retention problem that hampered him
his whole career. He states that FLEX Senior Writer, Julian Schmidt
would see him a few weeks out with striations on his glutes.
He found out later he had a bad case of Candida, so when he'd start
to carb load, the yeast would feast on the carbs and he'd retain water.