There is a widely held belief that artificial sweeteners and diet fizzy drinks are inherently bad for your health, now I want to look at whether this is actually true or not. Are sweeteners bad for your health? Is it just a myth or is there some truth to the idea? Can they even have a useful place in your diet?

Are they uniquely unhealthy?

A lot of the early research in this area came back with strong links that people who regularly consumed diet soda were associated with a 36% greater relative risk of metabolic syndrome and 67% greater relative risk of type 2 diabetes compared to people who didn’t drink them. They also showed that people who regularly drunk diet soda had a significantly higher body mass index (BMI). Let’s just think about this for a second, these studies were based on OBSERVATIONS, and on the whole people who drink fizzy drinks daily don’t tend to be particularly health seeking so when you factor in all the other non health seeking behaviours (fast food, smoking, alcohol, no exercise, little vegetable intake etc) of course they are going to have higher BMI and risk of diabetes etc. On the other hand, perhaps these people were fully aware that they were unhealthy and overweight, so had consciously made the switch from full fat fizzy drinks to diet fizzy drinks as an effort to try reduce total calories form their diet to lose weight! These studies cannot prove that artificial sweeteners cause  weight gain, diabetes, high BMI etc, that is like saying that just because a lot of murderers wear black shoes that black shoes are causing people to become murderers. 

Can diet drinks help you lose weight?

Yes, swapping out full fat fizzy drinks (or just high calorie sugar drinks) with zero calorie drinks like diet coke, has consistently shown a decrease in BMI, fat mass and waist circumference. This is simply down to a drop in calories, if you think some people may have 2-3 normal size cans of coca cola (330ml) per day that amounts to an extra 417kcal approximately! If you’re trying to maintain a calorie deficit this is a huge chunk of calories you’re allocating to something that provides little to no nutritional benefit. So dropping that much out of your diet, even if kept training exactly the same and eating exactly the same, would see a noticeable difference in weight and fat mass. 

“But they’re full of chemicals!”

The main chemical in diet soda drinks that people talk about is ‘aspartame’ which is just a zero calorie sweetener they use to make it. Thats what makes the diet drinks unique, they have something in them that has zero calories but still gives it a sweet taste! We used to think that perhaps this chemical was bad for us and a lot of these conspiracies came from the US in the 70’s and 80’s, mainly from a fear of the unknown. There is a saying that “it’s the dose that makes the poison”, just like paracetamol or aspirin if you take too much of you can die. All the research on aspartame was done in rats, now these have very little relevance when talking about humans because animal studies very rarely translate to humans, we are not rats! Also the amount of aspartame that they fed the rats in these studies would be the equivalent of us drinking boat loads of diet coke a day, in which case yes you may run into some complications, just like if you grossly over-consume anything in life, even water. There has never been a single study done in humans that shows normal doses of aspartame found in diet soda will do any harm whatsoever, however a study by De La Hunty in 2006 confirmed that “using foods and drinks sweetened with aspartame instead of regular sugar is an effective way to maintain and lose weight without reducing the palatability of the diet.”

Do they have a place in your diet?

Now there could possibly be a negative effect on gut bacteria by massively over consuming diet sodas but all the research in the area is so early I couldn’t possibly say right now, at the moment it’s suggesting that is probably doesn’t. So is there a benefit to having these drinks? If you’ve ever dieted properly in your life for whatever reason you’ve probably come across sugar cravings from time to time. If you happen to be on a low calorie diet trying to lose a lot of body fat and these sugar cravings kick in what do you do? Do you crack and nail a full tub of ice cream then guilt trip yourself on the treadmill for an extra hour the next day? No, you can just have a can of diet coke to trick your brain into satisfying the sugar craving having spent ZERO calories from your daily budget and keep moving forward with your progress, easy. A couple of cans of diet soda will do very little harm in your overall health and physique in the long run, a lot less harm than binging on something high calorie would have put it that way! So to conclude, there is NO strong evidence for negative effects of sweeteners on health, so enjoy in moderation.