I know some one who has lost a startling amount of weight over the last 12 months. He says it's been achieved by always saying no to anything sweet (apart from fruit) so no cakes, biscuits, chocolate etc.
Other than that he eats exactly what he wants and a much as he likes and exercises moderately. I can vouch for the fact that he doesn't appear to have denied himself in other ways, he practically ate the whole cheese board with loads of bread when he was here over Christmas
and he had plenty to drink too.
As I'm a bit of an all or nothing girl (i.e. I can have no chocolate, but I can't have just one piece of chocolate) I think I might be able to stick to this better than just cutting down iyswim.
My friend has been incredibly strict on this, wouldn;t have Christmas pud or birthday cake for example, because he's worried that if he had a taste again he'll undo all his good work, which I understand.
But, aren't there circumstances when it's rude to refuse point blank to eat what someone has prepared for you? I'd feel particularly uncomfortable about refusing to share someone's birthday cake (without a medical reason) for example.