Can artificial sweeteners cause weight gain?

Many people use artificial sweeteners because of the marketing messages directed at us by food companies: "drink this diet xyz instead of regular xyz because it has less calories".

While people continue to drink massive amounts of diet sodas all over the planet, obesity, diabetes, and heart diseases continue to explode at alarming rates worldwide.

Do artificial sweeteners have anything to do with it?

A number of studies have linked artificial sweeteners to a range of health problems, including weight gain, reduced insulin sensitivity (pre-diabetes), heart problems, and more.

There have been many theories floated by nutritional scientists over the years to explain why this happens, including:

  • Artificial sweeteners cause the body to produce insulin (just like sugar does), causing you to get hungry again very quickly and crave sugary foods (and therefore gain weight).
  • Artificial sweeteners mess up the gut microflora (the composition of bacteria living in our digestive system), which cause serious health issues, including food allergies, sensitivities, and weight gain.
  • People who consume "diet" drinks tend to overeat because they get a false sense of comfort from drinking "diet" drinks (while people who drink sugar-sweetened beverages tend to be more careful and count their calories more).

Is there any truth to these claims?

Well back in 2016, a group of scientists from the National Institute of Health and George Washington University took 30 healthy adults, split them into groups, and gave them different combination of "diet" drinks, including Diet Rite Cola and Diet Mountain Due (link to full study here).

All of the drinks given were sugar-free and sweetened with different combinations of artificial sweeteners, including sucralose and / or aspartame.

The results of the study were clear:

ANY combination of "diet" drinks and artificial sweeteners caused a significant increase in Insulin lasting more than 2 hours after EACH drink.

Why is this important?

Well Insulin is known as the "fat storage hormone". It is secreted by our pancreas every time glucose (sugar) levels get too high in the blood. Its job is to reduce the glucose level in the blood by pushing all the excess glucose out into muscles (when you're training) or to the liver to be converted to triglycerides (fat).

When insulin shoots up because of artificial sweeteners, 3 things can happen:

  1. If blood glucose is high when you drink that "diet" drink (for example you're drinking a diet coke with a sandwich), Insulin shoots up, and takes all that glucose from the sandwich and pushes it to the liver to be converted to fat. Result? Weight gain and overworked liver.
  2. If Insulin shoots up in the absence of high blood glucose (e.g. drinking a diet drink on an empty stomach), blood glucose levels will drop too much, you get cranky, hungry, and crave sugary foods (because your body needs to bring back glucose levels to normal. It would take a quarter of a chocolate bar to do that, but who eats only a quarter??? ;-)).
  3. If Insulin shoots up multiple times each day (with every food you eat + every diet beverage you drink): your insulin "sensitivity" drops. Result: weight gain and pre-diabetes. If this continues, the Pancreas (which produces Insulin) gets so overworked that it starts to shut down (welcome diabetes!).


What to do? 

Well personally I don't touch the stuff. Never have never will. 

I rarely use a natural sweetener (organic stevia) and only very strategically: in my post-workout bowl of oatmeal for example, because I actually WANT the Insulin spike post-workout to drive the glucose from the oatmeal into my muscles to recover faster.

Remember: the more you eat "sweet" foods, the more it takes to satisfy your craving for sweet foods. It starts with 1 diet soda, and it soon becomes 2, then 3, etc.

You don't want to go "cold turkey" and quit everything at once, as this will be difficult for more people and will only backfire. So my suggestion is to get a piece of paper and pen, start by writing down the number of artificially sweeteners drinks & foods you consume today, and start to gradually remove 1 at a time over the course of 30 days till you get to 0.

On that same piece of paper, note down how you feel! Your energy levels, your sleep quality, etc. I bet you'll experience a remarkable result!

Let me know how it goes in the comments below, and as usual, if you have any questions / comments, just drop them in below!