Why is Diet Soda Bad For You? Discover the Truth!


When talking to people about weight loss, invariably the topic of diet soft drink, pop or soda gets a mention (to avoid confusion during this article I will refer to these drinks as soda), as such I have decided to address the topic I have decided to explore why is diet soda bad for you?

Now, unless you have been living under a rock or you just have rocks in your head, you know that drinking soda will derail your weight loss efforts.

Fundamentally soda is bad for you (no kidding)! Bad for your teeth, bad for your general well being and very bad for your weight.


To illustrate the point, a 355ml can of Coke contains 140 calories and 39 grams of sugar! That is a huge amount of sugar!


To demonstrate how much sugar this is, watch this video.




Would you eat that much sugar by choice? The answer I hope, would be no. The reality is, we can slam down a can of Coke in less than 5 minutes and in doing so are drinking 9 teaspoons of sugar.

Common sense dictates this is an unhealthy practice and when trying to lose weight and should be avoided at all costs.

Are Diet Sodas Bad For You?

So what about diet soda? Are diet drinks bad for you? Can they be consumed when you are trying to lose weight?

As most people would do when trying to answer questions such as this, we will ‘Google’ it. Give it a try! I Googled ‘why is diet soda bad for you’ and got about 2 million search results ranging from diet sodas will make you fat, to diet sodas have no effect at all on weight loss.

So where does that leave the average person who is trying to lose weight? Confused? You Bet!

At a basic level diet soda appears harmless to our weight loss efforts, after all it has zero calories and zero sugar. Now, fundamentally weight loss is a simple equation of a person using more calories than consumed, forcing your body to burn stored energy sources such as fat, which results in weight loss.

What The Research Tells Us

In terms of how diet soda affects weight loss, theoretically they should be fine because they contain no sugar or calories. Unfortunately not everything is life is that straight forward. When looking at the research it gets even more confusing, as numerous studies site diet soda as a cause of weight gain whilst others state diet soda will aid weight loss.

Without going into the merits of all of these studies (some of which don’t even credit their sources), it is safe to say an argument can be mounted on both sides. It seems, as with a lot of health and fitness related topics, opinions can be divided.

Probably the most reputable and convincing study that I found was from the San Antonio Heart Study, where there was a direct correlation between the amount of diet soda consumed and an increased chance of weight gain:

Why is Diet Soda Bad For You?

“On average, for each diet soda our participants drank per day, they were 65 percent more likely to become overweight during the next seven to eight years, and 41 percent more likely to become obese,” said Sharon Fowler, M.P.H., faculty associate in the division of clinical epidemiology in the Health Science Center’s department of medicine.”

What the study doesn’t tell you is why there is a correlation, in fact the causation for the weight gain is unclear.

In trying to interpret the results Fowler hypothesizes that: “It may be that normal-weight people in our study whose weight had been increasing had switched to diet soda in an attempt to stop their weight gain,” she said. “That’s a very real possibility. Another is that drinking soda, either regular or diet, is part of a lifelong ‘Obey your thirst’ nutritional pattern that sets a person up for weight gain later in life. Whatever the case, our results definitely raise more questions than they answer.”

But Fowler pointed out whenever someone is drinking a diet soda, he or she is drinking it to the exclusion of healthier alternatives such as milk, water, or juice. “Can you think of one good thing that comes from a diet soda can for your body? You’re giving yourself the taste of nourishment without any at all, so it may be that you then seek it from other foods, such as high-calorie desserts,” she said. “Even though you fool your tongue, you don’t fool your brain. It is not satisfied. I’ve seen people plunk down a doughnut and a diet soda on a convenience store counter. What our analyses indicate for sure is that drinking diet sodas will not protect a person from the health effects of the rest of his or her lifestyle.”

Personally I believe the study, which was conducted over a long period of time, involved a wide range of participants within the community. These participants bring with them a range of factors, that were not measured by the study, which could have influenced their weight gain. Factors such as individual health, genetics, wealth, employment, stress and a range of other variables all could have impacted the participants weight gain, not the diet soda alone.

Regardless of the reason why, the study still indicates that drinking diet soda leads to weight gain. Is it conclusive? No! Is it something you should take into consideration when trying to lose weight? Definitely?

My Biggest Problem with Diet Soda

Fundamentally, when trying to answer the question ‘why is diet soda bad for you?’, my biggest issue is, you don’t know what the hell is in it. It tastes nice and is refreshing, but in it’s rawest form it is a bunch of chemicals that have been carefully blended to create a drink that has absolutely no nutritional value.

Common sense tells us that placing unnatural chemicals in our body on a regular basis is not a healthy practice. Imagine what it is doing to your insides!



Take a look at this video to see how harsh the chemicals in soda can be!




My Opinion on Diet Soda

Diet versions of sodas are a better option if you are trying to lose weight, however it is still unnatural and studies are showing that, whilst we are not sure why, people are still gaining weight consuming diet soda.

Does that mean that a can of diet soda every now and then is going to derail your weight loss plan? No. But what it does mean is, if you are drinking diet soda everyday, thinking that you are choosing the healthier option, you are mistaken. You are consuming far too many chemicals for my liking.

In a perfect world I should be telling you not to drink soda all together. But I won’t. Why? Because I’m not perfect, I still enjoy a social drink and I choose to use diet soda as my mixer. I consider diet soda to be the lesser of the two evils.

What I can say, is I no longer drink diet soda during the day. If you are drinking diet soda everyday look at cutting back, especially if you are drinking it to quench your thirst. Choose water instead.

If you are struggling on your weight loss journey, you should consider taking a look at my recommended nutrition plan <— Link to Website. Once your nutrition is in order I recommend you have a look at my recommended training program for women <— Link to Website or my recommended training plan for men <— Link to Website.


Drop me a comment below to let me know your thoughts or how diet sodas have affected your weight loss plan (positive or negative)

  1. Hi Niko, REALLY informative post. I learnt a lot.

    I used to drink sodas A LOT when I was a teen but lately now that I weight train I find that my desire for soda is no longer there especially because of what it does to my gut -EXPAND! I do have sodas once every few weeks but I try to avoid having them as much as possible.

    My opinion is that drinking too much diet sodas will only lead you into unhealthy options just like the guy you stated in the article who was drinking a diet soda with a doughnut.

    We need to go back eating as natural as possible and stay away from all the processed and unhealthy foods.

    • Chris,

      I’m like you, when I was younger drank my fair share of soda. Now days I limit it to using it as a mixer when I have a drink socially. Probably not ideal, but I’m a real persons that enjoys having a drink with my mates.


  2. Niko,

    I actually don’t drink soda…at all. It’s just empty calories that sneak their way in with a meal. If weight loss is on the agenda, it’s best to stick with this approach.


  3. Mitchell,

    You are spot on about soda being empty calories. I don’t know anyone who is lean that regularly drinks soda.


  4. It is interesting how studies continue to show that diet soda drinkers tend to gain weight over the long haul…I wonder how much of it is the diet soda itself or the drinker. Take both Chris and Mitchell above as examples: healthy, not trying to lose weight and don’t drink soda. The average diet soda drinker tends to be overweight already and is using as diet soda as a crutch. They already have suspect health habits, so I bet they would still gain weight even if they drank water or unsweetened tea.

    Don’t get me wrong, I am not saying to go ahead and drink diet soda because I loathe artificial chemicals in the diet. What I am saying is that folks need to address the real reason they became overweight.

    Great write up by the way.

    • Thanks Richard, you are exactly right no one factor can be attributed to a persons weight gain. A holistic approach needs to be adopted, diet, lifestyle, environmental factors, level of activity, stress, medical conditions and a range of other influences need to be addressed. If a person can identify and resolve these issues one at a time, then they will be well on their way to losing weight and keeping it of.

  5. Very interesting facts on diet soda. Fortunately I’ve never been a soda drinker but this reinforces that water should really be the primary beverage of choice…very few risks and it should help reduce your weight rather than cause weight gain like other drinks.

    • Dave,
      As you say water should be your primary source of hydration. I must admit as a young bloke, I fell into the trap of drinking soda to quench my thirst on hot days, I’m just glad I was able to all but cut it out of my life.

  6. Thanks Niko for this article.
    No news here, just nice to have a quick reminder why I avoid sodas, even diet.

    Here and there I find myself craving a soda, and as soon as I take the first sip, I remember I only craved the idea I had of the soda. Its way to sweet now for my taste. And this coming from a guy that used to drink a 0.5l coke every morning.

    Something I can not give up though is my sparklink water. I love the fizziness and it gives me a sense of comfort.
    Something that is really popular in Germany especially for sportive ppl. is apple spritzer. You take unsweetened apple juice and mix it with club soda. Really refreshing and so much less suggar for you. With this in mind I have been experimenting with many different types of natural fruit juices and I love the different types of refreshing drinks I can create now. If you are loosing weight you still have to watch the ratio, as fruit juices are still fairly high in suggar.


    • Ben,
      Sounds like a great alternative for those times when you feel like a fizzy drink. I imagine the amount of juice you add is pretty low, therefore the sugar content would also be pretty low as well. The added bonus is the absence of chemicals. Thanks for you input.

  7. I used to be an avid diet soda drinker until i started seeing side effects such as sleep loss, skin rashes etc. Cutting the soda seemed to cut the issues.
    When I’m craving the ‘fizz’ ill general hit up a soda/mineral water instead.

    • I was the same for years, thinking I was doing the right thing in terms of weight loss. Glad I know better now!

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