The effects of artificial sweeteners still stands as one of the most controversial topics among the public when it comes to nutrition.
Just bring up diet soda at your next family dinner if you want proof.
Do they cause cancer, weight gain, increased cravings, or a general tendency for evil?
Today, we’re breaking down whether or not diet soda, and artificial sweeteners, will make you gain weight.
The main claims we’ll cover are these:
Artificial sweeteners cause weight gain
Artificial sweeteners cause an increase in appetite
How weight gain works
We know calorie balance determines whether we gain, lose, or maintain our body weight.
So:
eating more calories
doing less activity
or a combination of the two
is required for meaningful weight gain.
Since sweeteners are all nearly zero calories, then this claim suggests that there must be an independent variable OUTSIDE of calorie intake that drives weight gain from sweeteners.
This is just not anything we’ve seen in any of the evidence we have available.
In fact, we see something much closer to the opposite…
In 2021, a group of researchers in the UK analyzed the current data we had on artificial sweeteners.
They compiled the data of 88 separate studies they deemed appropriate.
Their meta-analysis found 51 studies that directly compared consumption of sugar and low-calorie sweeteners.
They found that the people who consumed low-cal sweeteners had a significantly lower calorie intake than those who consumed full sugar beverages… no surprise there.
The other finding was that the people who consumed low calorie sweeteners noticed an average change of anywhere between 0.5kg to 1.5 kg.
Which makes sense, because reducing your calorie intake will result in body weight reduction.
But here’s the crazy part.
These studies included both parallel-group studies, AND crossover studies.
In a parallel study
Subjects are divided into two separate groups, and given individual interventions, and the effects are recorded.
In crossover studies
Subjects are divided into two separate groups, and given individual interventions, then undergo a wash out time period, before receiving the opposite intervention.
Like this:
And we see the same results repeat themselves…
People who switch to artificially sweetened bevvies from regular sugar sodas, lose weight.
People who switch to drinking sugar sodas – weight gain.
It’s not like artificial sweeteners are magical
And sugar probably isn’t evil either.
The reason they cause a reduction in body weight when replacing sugar is simple.
Because sugar contains calories, and sweeteners don’t.
So we can pretty much rule out the idea that there’s something nefarious about sweeteners that causes weight gain at this point.
In fact, I’d wager that the lives of millions would be improved (or even saved) if there was an additional tax placed on sugar-sweetened beverages.
Think of the relief the healthcare system would experience from two decades of weight loss in the general population due to the mass-acceptance of low-calorie sweeteners.
Now let’s take a look at the next idea…
Sweeteners cause an increase in appetite?
In this study, by Anton and colleagues we had 31 subjects enter the lab on three different days.
They were all given a 469 calorie breakfast to start.
Then, they were given a small ‘pre-load’ meal of tea and crackers with cream cheese.
On three separate visits, they were given three different types of cream cheese.
One third of the cream cheese was sweetened with sugar, a third sweetened with stevia, and a third sweetened with aspartame – the subjects weren’t told which was which.
After their pre-load meal, they were encouraged to eat as much or as little as they liked at a lunch or dinner buffet.
The participants recorded their fullness on a scale from 1-100 before and after meals, at multiple intervals.
They also gave blood samples at various points surrounding the meals.
So what happened?
Funnily, the group rated the aspartame sweetened cream cheese as the best tasting of the three.
Each group reported fullness levels that were nearly identical
Each group also ate a nearly identical amount of food at the buffets.
Except that the sweetener groups ate 300-330 calories LESS than the sugar sweetened cream cheese group, since that was the only difference.
They also experienced a significantly lower blood glucose response at 20 minutes after meal time, compared to the sugar sweetened group.
This study, although small in it’s sample size, suggests that sweeteners don’t have a meaningful effect on appetite.
If anything, they help you feel MORE satisfied per calorie, than sugar does.
Which means that if you were to replace the sugar in your diet with sweetener, you’d likely start eating fewer calories without knowing the difference (both in taste, and in appetite lol).
Here’s another randomized control trial
They looked directly at the claim that sweeteners cause an increase in appetite – from 2020 by Stamataki and colleagues.
They provided 20 subjects with one of four beverages, before measuring their blood sugar levels, appetite, and calorie intake at a lunch buffet.
Chips, fruit, cookies, ham sandwiches, and fat-free yogurt were available.
They were given either:
water (unsweet + 0 cal)
water sweetened with glucose (sweet + 160 cals)
water sweetened with sucrose (sweet + 160 cals)
water sweetened with maltodextrin (unsweet + 160 cals)
water sweetened with stevia (sweet + 0 cal)
They had their drink, then got to enjoy a lunch buffet afterward.
Can we guess who at the most calories that day at the lunch buffet?
Sure enough, the group with water only consumed the most calories at lunch.
The calorie-containing beverage groups consumed slightly less at lunch, but around the same total amount of calories when the beverage was accounted for.
The stevia group consumed the fewest total calories.
Again, we’re seeing that these sweeteners don’t cause you to eat more food to somehow ‘make up’ for the calories they helped you avoid.
These findings line up with the findings from a 2009 paper that looked at people in the National Weight Control Registry
They looked at people who’ve lost at least 30 lb and maintained it for at least a year
People who had lost a significant amount of weight and kept it off were drinking roughly 3 times as many artificially sweetened beverages as people who had never lost weight.
So folks…
It seems like artificial sweeteners are an effective way to reduce the overall calorie intake of your diet without having a significant impact on your appetite.
And if anything, diet soda probably makes you leaner, and not fatter.
If you want to lose weight, and you’re currently intaking a lot of sugar sweetened beverages and foods… consider switching.
It could be a huge deal for you.
If you’re already on the weight loss journey, and looking for a way to enjoy sweet treats without adding too many calories, consider adding in artificially sweetened treats.
They can help you with sweet food cravings without the calories, and might even help you feel more satisfied along the way!
Another reminder to focus on the big rocks when it comes to your fitness goals.
Things like training, sleep, and how much food you’re eating are massively important compared to little details like this.
Thanks for reading!
Matteo
PS: If you want to take control of your weight, you should read my blog post The Ultimate Guide to Weight Loss for Beginners.
