Do diet drinks slow weight loss?

You have no doubt heard someone tell you all about the evil chemicals they use to sweeten drinks. They can cause cancer, multiple sclerosis or even in one case, made this guy's leg drop off.

In reality artificial sweeteners are the most studied food additive known to man. There have been hundreds of studies conducted on these chemicals and reviews of the studies show that there is no link between risk of disease and the sweeteners. The problem comes from the occasional study that indicates a slight statistical anomaly, which is then reflected in the paper's title. For example a study from the European Ramazzini Foundation of aspartame in rats showed increases in various neoplasms. The paper was reviewed by the European Food Safety Authority (EFSA), and the report was found to be flawed. Their review stated 'The data on total malignant tumours do not provide evidence of a carcinogenic potential of aspartame.' Unfortunately the conspiracy nuts or the alternative therapy peddlers cherry pick these flawed studies to support their own claims, and in turn sell you their products.

Another claim that is doing the apocryphal rounds on the net is that the sweetness of the artificially sweetened drinks can trigger the body into releasing insulin and start up the digestion process. This is again a result of people cherry picking the science to back up their claims. The digestion hormones are released by the pancreas and other organs in response to blood glucose level and as part of the cephalic phase of digestion.The cephalic phase is where our mouth waters at the thought or sight of food.

The original claims were based on an animal study where the test subjects were fed sweeteners and the vagus nerve* was stimulated and the response of cephalic phase insulin release was monitored. Many human based studies** have shown that this effect is not replicated in humans.The chemical structure of the different sweeteners are incompatible with the glucoreceptors that report into the brain and pancreas when we eat sugary foods.

The most recent rant about artificially sweetened drinks is based on several reputable news sources reporting part of a report based on weak science. The claim is that fat folk who drink diet soda consume more food based calories than the chunky folk who enjoy the full fat sodas. The reports typically lead with attention grabbing headlines. What the reports fail to mention is that none of the people interviewed were eating balanced diets. When the study is read correctly, the bottom line is that people who eat poor food choices and drink diet soda may consume more food calories because they 'save calories' on the diet drink.

When you look at the overwhelming evidence proving the safety of sweeteners, the evidence that they don't upset our hormone balance and the fact that when used as part of a restricted calorie diet, they provide a low calorie alternative to high sugar drinks.

I've lost weight whilst drinking diet cola, my blood pressure has dropped and is almost at a normal level. My recent blood test shows I'm not at risk of diabetes and have normal cholesterol levels. I think I'll go with the scientists on this one, and enjoy my Pepsi Max as part of my healthy eating plan.

The science.
*The vagus nerve is the main facial nerve that is stimulated during the cephalic phase of digestion. It causes the brain, stomach, liver, intestine and pancreas to prepare for food consumption.

** http://www.ncbi.nlm.nih.gov/pubmed/9734727
http://ajcn.nutrition.org/content/49/3/427.full.pdf
http://www.ncbi.nlm.nih.gov/pubmed/7652029
http://www.ncbi.nlm.nih.gov/pubmed/3046854
http://www.ncbi.nlm.nih.gov/pubmed/21245879

NB. Aspartame is broken down in the body to form a number of chemicals, one of which is called phenylalanine, an amino acid found in all proteins. People with a rare genetic disorder called Phenylketonuria (PKU) cannot process this chemical normally. People with PKU must be aware of foods that contain phenylalanine or sources of phenylalanine.