water water n more water !!!
u wont believe the difference....
couple of days a week go to the gym n do some light weights at high reps, this will tone not bulk up!
try n go walks/runs every nit alternate each day between walking and running this will help your stamina...
cut down on food not as in lik stop eating but watch your portion sizes and try n eat more vegetables, fruit, lean meats and try and avoid things high in fat, sugar, salt and also very high carbohydrates such as potatos, pasta and white bread.
This will all help but dnt think getting your teeth whitened will do anthing apart from lose you some well earned money!!!!!
Hope this helps you
Paul x