BTW the "Guess who" 255 and gaining is of course Whitney Houston. Her metabolism has been screwed up from years of cocaine abuse. Now, without the artificial outside stimulants, her system has become lethargic. Everything gets stored instead of burned. Something similar, to a lesser degree, happened to model and Species actress Natasha Henstridge.
Though born in Springdale, Newfoundland and raised in Fort McMurray Alberta (Ft Mac is one of Newfoundland's largest cities!), by 15 she was living in Paris and working as a high end fashion model. In order to keep her end high The Tash, by her own admission, used a lot of diet aids that are no longer on the market. She explained that at the time she didn't see it as cheating; they gave her the energy to exercise more (just like steroids do to pro baseballers!).
Anyway after having kids Natasha decided it was time to clean up. So she went stimulant free. The result was that she put on about 10 pounds. Not a lot on a 5'11" woman with her frame. Still it was enough for her to speak about it on TV. Henstridge said that now the 10 or 15 won't budge. So years of diet pill abuse may have thrown her metabolism slightly off kilter. It's not enough to keep Henstridge out of a bikini down in Malibu, and no one in Malibu is complaining about the view!
Besides, in Natasha's defense, even highly active persons can have an occasional weight issue.