Not with the IFBB politics 
He actually grew about 10-15 lbs in some of his later shows and still placed well. I think he was 275 at the 96 Olympia (the show where these pics are taken), and still won the Arnold Classic at 289, 3rd at the 98 Olympia at 280, and 2nd at 97-98 Arnold Classic at 285.
His placings began to drop not due to chasing more size but after his divorce with his former wife, as in the immediate term it had a huge emotional toll on him and he began to lose motivation and get fed up with the unfair judging decisions. Lots of people actually underestimate the importance of having someone supportive to prepare your meals and help you during your contest prep. Even guys who were single like Kevin Levrone would hire someone to prepare their meals for them.
excellent, accurate and insightful post from bigbobs.
i think many getbiggers have never competed in a BB show and have no idea of the discipline and dedication it takes to get into ripped contest condition as Nasser always did.
not only that but the diet must be meticulous- and if youve ever done it- you know the amount of time and work that is involved to go to the shops, buy the food, prep it, cook it and clean up afterwards.
its a full time job and it never ends.
and when you are dropping carbs and are depleted, tired and irritable it is another major burden in the road to getting into contest shape.
many of the Pro's have other who do their food- Cutler had a cook for the vegetable (cooks his own meat so it is fresh though), levrone had his cooks, ronnie had his mom making his food.
it really is a time consuming chore. and undoubtedly Nasser having Bisera to do all his food prep was a major factor in helping Nasser get into contest shape with a minimum of stress.
