This conundrum has been known for some time, but there is further research by , David S. Ludwig, MD, PhD,  a Harvard professor and Founding Director of the Optimal Weight for Life (OWL) clinic at Children’s Hospital, Boston.

He refers to research showing that rats get fatter when fed on artificial sweeteners than if fed on sucrose - normal sugar. The hypothesis is that the sweeteners interfere with our body's regulatory systems. The body thinks - Whoopee, calories on the way - then the sweetness comes, but big disappointment, no calories. So we start to seek out calories from somewhere else.

Another important comment he makes is that artificial sweeteners are really, really sweet, and we get hooked on this intense sweetness. As a result, natural sweetness, such as fruit, just is not sweet enough. Artificial sweeteners train us to want this intense sweetness. Note that they are only available in manufactured foods, notably in sugar free fizzy drinks, all of which are heavily advertised.

So, help yourself by avoiding fizzy drinks. Drink more water. To help you lose weight.