Artificial sweeteners, ubiquitous sugar substitutes, do not help you lose weight and can pose long-term health risks, the World Health Organization has warned. Replacing sugars with these sweeteners "does not help with long- term weight control," the WHO says.

The most common sweeteners are acesulfame potassium, aspartame, advantame, cyclamates, neotame, saccharin, sucralose, stevia and its derivatives. The recommendation is valid "for everyone except individuals who suffer from pre-existing diabetes," says the WHO.