Gaining

Diet soda: myth or legend

I think the current answer is "we don't know". There haven't been many studies on the subject, but those that have been conducted seem to indicate that there may be a counter-intuitive link between diet soda and weight gain.

One observational study demonstrated a correlation between increased diet soda consumption and weight gain. Correlation isn't causation, of course, let alone an indicator of what mechanism may be behind it. For example, it is one thing if people are substituting regular soda for diet soda (that would be counter intuitive), but the result would make a lot more sense if people were drinking diet soda instead of water.

Possible causes for the effects observed include:

- Artificial sweeteners drive greater sugar cravings rather than satiate them, i.e. diet soda doesn't make you fat itself, but drives changes in diet that do.

- Artificial sweeteners directly damage metabolism, leading to subsequent weight gain.

A 2008 study, which controlled for diet, exercise and other factors, looked at a variety of factors which affected incidence of metabolic syndrome. A "Western style" diet was associated with an 18% increased risk, but diet soda came out on top with 34%.

Another study looked to control for eating habits, and found that participants people who consumed more artificial sweeteners gained more weight, but only an average of 2 lbs over the course of a year.

Lastly, a study on mice adds credence to the idea that artificial sweeteners themselves are the direct cause of weight gain. Rats were put into two groups, each of which has access to as much food as they liked. One group was given artificial sweeteners on top of this. This group ate the same as the control group (indicating that sweeteners don't induce cravings) but gained more weight.

So it would appear that diet soda doesn't boost appetite, but that artificial sweeteners themselves could induce weight gain through metabolic damage. But these are small, sparse studies (and one isn't even on humans!) so it is difficult to draw concrete conclusions.
12 years

Diet soda: myth or legend

It might also be the case that people who drink diet soda think 'oh, I'm being good by having a diet soda, so I can have a chocolate bar/burger/bag of crisps as a treat' and end up consuming more calories that way than they save by not having a sugary drink.

I'm fairly sure the diet sodas have also been linked to some (non-weight) health issues too.
12 years

Diet soda: myth or legend

Even though I prefer the taste, I tend to avoid diet coke (don't have much experience with other diet sodas) because it really does seem to make me so painfully hungry!

When I was at school I didn't eat during the day at all, once I got to sixth form I started buying diet coke at lunch time from the shop down the road, and within an hour or so I'ld feel my stomach growling. It was the first time in years that I really suffered from physical hunger!

I drink it now if I'm at home/somewhere where food is available, and it seems to be ok if I'm drinking it with spirits on a night out. I don't drink it when I'm out during the day, at uni or at work though because it still has the same effects, I've made the mistake before and by the end of a work day my stomach feels like it's eating itself!
12 years