For decades, people have turned to diet soft drinks as a healthier alternative to regular soft drinks. However, consuming diet soda on a regular basis may have some serious health risks, including weight gain. It may seem counterintuitive to suggest that diet sodas may be causing people to gain weight, particularly because these sodas are commonly consumed by people who are trying to lose weight. However, the chemicals consumed from the artificial sweeteners found in some diet sodas may increase a person’s risk of obesity. It’s not entirely what you are consuming that can cause weight gain but what the body thinks it is drinking (or eating) that plays a role.

So, the reason alot of people fall for believing diet soda will do no harm to them, is that the nutrient value of diet soda is:
Calories 0
Sugar 0g
Fat 0g
Of which saturates 0g
Salt 0g

And that is all the diet soda can wants you too notice. Well if it contains no calories/fat/sugar then it must be acceptable, right? Well your wrong, here is a list of ingredients the diet soda company’s will not want you to see:

Carbonated Water
High Fructose Corn Syrup
Caramel Colour
Phosphoric Acid
Natural Flavours
Potassium Benzoate
Citric Acid

Although all the above ingredients that play a massive role in the reason for weight gain, sweeteners pretty much take all the blame in this, and along with serotonin, they are the 2 biggest factors in this:


First factor is that there is something in the chemical structure of these sweeteners that alters the way the brain processes the neurotransmitter serotonin. Serotonin helps tell the body when it is full. When natural foods and sugars are consumed, serotonin signals to the brain to turn off your body’s appetite. However, artificial sweeteners may prolong the release of serotonin, and your appetite remains in full force long after it should have abated.


Another component of artificial sweeteners, particularly aspartame, is that these chemicals can trick the body into thinking it has, in fact, consumed sugar.

There are several factors involved in how diet drinks could contribute to weight gain:

1) If you offer your body something that tastes like a lot of calories, but it isn’t there, your body is alerted to the possibility that there IS something there and it will search for the calories promised but not delivered. This may be due to the insulin response triggered by the sweet “soda-like” taste. In other words, the sweet taste of diet soda tricks the body into thinking sugar is coming, so triggers an insulin release. Because there is no energy for the insulin to usher into the cell, the blood sugars drop — causing moods to drop, energy to drop, and appetite to be stimulated.

2) When the stimulated appetite drives one to eat something with calories, the free float of insulin (a fat storage hormone) is thought to cause more fat to be stored rather than burned for energy.

3) In addition, the dropping blood sugars cause fluid to pool in the abdominal area. Add caffeine and sodium phosphate and one can feel like a bloated mess, even if the scales don’t reflect a gain. 

4) There is also concern from many scientific camps about the impact of artificial sweeteners on chemistry of the brain – causing a decrease in “feel good” serotonin production that can trigger overeating and mood changes. 

So as this can lead to low blood sugar, which may cause you to eat a sugary treat in response. Having diet soda or eating a sugarless item once in a while won’t create any long-term effects. But repeatedly relying on artificial sweeteners could affect appetite and change blood sugar levels for good.

So the answer is simple, diet soda alone wont cause weight gain, it will create side effects that may lead to weight gain, however if it is consumed in moderation and combined with a healthy diet and lifestyle then consuming diet soda will be fine.

By Phil Downing

Personal Trainer in Liverpool @ Liverpool Personal Training Studios