I know I shouldn’t drink too many fizzy drinks, but are diet versions OK?
Sam Hart, by email

Controversy has always surrounded aspartame, the most widely used sweetener in diet drinks, which is better known by trade names such as NutraSweet and Canderel. Sweeteners, like other food additives, are tightly regulated and have their safety rigorously assessed, but while the Food Standards Agency has continued to approve their use, others have opposed it. Scientists have been investigating a possible link with brain tumours, and the most recent research has shown an increased cancer rate in rats that were fed aspartame. Since then, the European Food Safety Authority has been reassessing the safety of aspartame and will recommend what action (if any) needs to be taken.

Even if it’s proven to be safe, there isn’t much in diet fizzy pop that’s good for you so keep your consumption to a minimum and make sure most of your fluid intake comes from water, sports drinks and antioxidant-packed brews such as green tea.