There's lots of nonsense talked about diet drinks, so what is the truth? Are diet drinks, as many people claim, packed with toxins such as aspartame that will make you sick? Or even, as others suggest, can they make you gain weight?

Let's look at the aspartame argument first. Aspartame is a low-calorie sweetener, invented in 1965, which ounce for ounce is about 200 times sweeter than sugar. It is used extensively in diet drinks, so if you consume them regularly you'll likely be consuming aspartame.

The US Food and Drug Administration has set the safe daily intake of aspartame at about 50 mg/kg of body weight per day. So if you weight 75 kg, this would be the equivalent to around 20 cans per day.

Despite the scare stories often in the media, none of the peer-reviewed medical literature shows any relationships between the consumption of low calorie sodas and any of the 92 diseases that aspartame is claimed to cause.

But what about the argument that these sodas can cause you to gain weight? This actually has some support - researchers in Texas found that those consuming zero calorie sodas gained more weight over the study period than those consuming regular sodas.

Now of course, zero calorie sodas can't actually make you gain weight - they have no calories! What appears to occur, however, is that people think that because they are consuming a calorie free soda, they can relax and eat other foods more liberally. As a result, even though the soda is calorie-free, their overall diet has an excess of calories.