david rush , 33 , from lisburn , northern ireland , felt that he ` should n't go out ' because of his size but lost the weight after plucking up the courage to start cycling .
at his heaviest , he was forced to order specialist xxxxxl clothes on the internet - the result of topping up his takeaway-heavy diet with six bags of crisps and two bottles of full-fat coca-cola a day .
embarrassed by his size and afraid of cruel comments or being forced to squeeze past people .