Can Diet Coke Make You Fat?

Soda. Coke. Pop.

ept_sports_nba_experts-686956474-1256580685Whatever you call your carbonated beverage (it’s SODA, by the way), you’re probably already aware of how terrible it is for you.  Other than rotting your teeth, it’s also a huge reason there are so many overweight people in this country.  Check out this crazy story posted yesterday: Caron Butler (pictured) of the Washington Wizards was so addicted Mountain Dew that when he gave it up this summer, losing 11 lbs in the process, he went through actual withdrawals:

To try and give this up was crazy for me! I was going through withdrawals. I was in the bed sweating. My wife would turn over in the bed and ask “Are you OK?” Honestly, those first two weeks without The Dew [were] the roughest two weeks of my life. I’m talking headaches, sweats and everything. Before that I drank at least six 12-ounce Mountain Dews a day.

I know if you Google “soda weight loss,” you’ll find 2 million hits on how terrible these beverages are for you…so I won’t get into it.  Instead, I wanted to take a look at the effect of DIET soda on weight loss.  I know there are conflicting reports on whether or not this stuff can actually make you fat.


My Initial Thoughts Before Research

Diet soda has zero calories (generally) and zero actual sugar, which means it can’t directly make you gain weight, right?  A normal 20 oz. Coke, on the other hand, has 240 calories and 68 grams of sugar (holy ****), which definitely causes weight gain.  Now, if diet soda doesn’t have calories, it can’t contribute to the calorie equation (calories consumed vs. calories burned), which means diet soda alone can’t make you bigger.  However, is Diet Coke responsible for insulin spikes and increased appetite, which would indirectly cause weight gain?  Time to put on my nerd researcher cap and see what I can track down.

Sources I Don’t Trust

If you look up “diet coke weight gain,” you’ll find all kinds of articles that say Diet Coke is the devil.  Unfortunately, some of these articles site no sources and are written by people who are trying to sell their own supplements.  Other sites say that Diet Coke is perfectly fine for you, as it has no calories and therefore no ill effect (I would guess these articles are written by people who chug DC by the gallon).  As hopefully you’ve learned, not everything on the internet is true (shocking), and when it comes to fitness and diet our bodies are so complex that things are very rarely so black and white.

Sources I  Do Trust

After reading some of the crazy extremist websites, I tried to track down some actual studies (and not hearsay) that could prove or disprove the effects of diet drinks.  I came across this study from the San Antonio Heart Study, where the amount of diet soda consumed directly coincided with an increased chance of weight gain:

“On average, for each diet soft drink 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.”

Now, because diet studies always take place with people of various levels of health, wealth, genetics, and social standing, along with thousands of other variables that take place, I’m hesitant to place the blame squarely on Diet Coke.  Maybe the people who drink Diet Coke generally don’t take into consideration what constitutes a healthy diet, while people who don’t drink it generally could be more knowledgeable about their diets and thus eat better?  Maybe the heavy DC drinkers work stressful jobs (and ‘need’ the caffeine to stay alert), and the stress along with poor diet choices (from working late) is causing their weight gain?  I don’t know the full reasons and more research must be done, but the strong correlation between the two has me definitely leaning towards the “Diet Coke can make you fat” camp.  My defense your honor? Better safe than sorry.

I then came across this fantastic video on YouTube, already cued up to the proper part of the conversation where it talks about the effects of diet soda on your waistline.  I’m no scientist, but the guy makes a lot of great points in an easy to understand fashion.  Once again, I don’t have a scientific background (I was an Econ major in college), but after reading a few books on the effects of acidity and alkalinity on our diet, I would tend to agree with the makers of this video.

My Problem With Diet Soda

My big problem with Diet Coke is that I don’t know what the hell is in it.   I mean, if it tastes like soda, but doesn’t have any calories at all…what the eff are they putting in there?  Vin Miller over at (who is not surprisingly biased towards eating natural foods) breaks down the new ingredients in Coke Zero and Pepsi Max.  I’m a big fan of Vin’s and I certainly respect his opinion, as he always tends to lean towards the healthier/safer side of things.  Some of these can’t be good for you, no matter what the FDA says.  Speaking of which, I’m growing less and less trusting of the FDA by the day.  Check out this article where FDA scientists accuse their own administration of running the organization like the Mob.  Yikes.

My Conclusion

In my personal opinion, I’d say Diet Coke is the lesser of two evils if you’re trying to lose weight.  However, it’s still created in a lab with unnatural elements, and there are studies that have shown people who drink the stuff are more likely to be overweight.  Whether it’s directly the cause or simply part of a larger problem still needs to be shown, but the numbers don’t lie.  I think people who switch from a case of Mountain Dew a day to a case of Diet Mountain Dew are still going to have all kinds of health problems anyway…just a hunch. Regardless of what the FDA says, I’m not convinced that the stuff in Diet Coke and Coke Zero isn’t harmful, and I’m not convinced that because it has littler or no calories it can’t make you gain weight. Better safe than sorry, right?

My Recommendation

I recommend that you cut back on soda/sugary drinks as much as possible, even if they’re diet, if you’re trying to lose weight.  Even if you’re not trying to lose weight, give it up!  It’s not good for you.  If you’re drinking soda, don’t do so at the expense of your water consumption.  If you need “fuel” for a marathon session of Aion (a new MMORPG my friends are hooked on), you better be double-fisting some high-quality H20 with that diet Dew.  If you think water is too boring, you have to decide what’s more important: your health or your sweet tooth.

Now It’s Your Turn

These are my thoughts and opinions, but what do I know? I’d love to hear some actual stories from you guys and how soda and diet soda has affected your weight loss and health.  If you’ve given up regular soda and switched to diet and lost a lot of weight I want to know.  If you’re struggling to lose weight but you can’t kick your Diet Coke habit, I want to hear about it.

Please leave your thoughts in the comments.



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  • Sikosis

    I’ve been drinking Diet Coke for 31 years to date, because I like the taste. It’s mainly all I drink, I don’t drink it to lose weight and have never found it making me want to eat more food. I would say I’m addicted to it, due to the caffeine, I drink 2 cans a day to get through a work day.

    Maybe one of these days, I’ll try to kick it and see what the results are.

  • Colin

    Caffeine has the effect of constricting the blood vessels in your brain. If your blood vessels are always constricted then your brain moves into all that extra space. Once the caffeine has been removed and the blood vessels go back to their proper volume, your brain has to be moved/pushed back, thus causing the headaches. Do you best to cut back on the caffeine, your brain will thank you later.

  • Jennie Slater

    I drink to much pop I gained weight to much diet coke you are right diet coke is not healthy for us even me beth Finn drinks to much diet coke not me I drink diet Dr pepper that’s free for me I can have 1 can a day

  • david nicholls

    I’ve put on weight in the last week, the only change I can think of is I’ve been drinking a few cans of diet coke each day instead of my usual tea at work, seems unlikely such a sudden gain could be explained by diet coke, but seemed worth mentioning.

  • david nicholls

    one other thing I just thought of is what psychologists call the ‘licensing syndrome’ which basically means “I’ve done something good, now I can do something bad”, probably a universal phenomenon. Putting a Greenpeace sticker on the bumper of your SUV would be an example. Most people know to avoid someone with a really good cause. It may be that after virtuously drinking something with “diet” written boldly on it people feel “licensed” to pig out. It is possible to become aware of this phenomenon and resist it.

  • Barry Harrison

    its no big deal, just don’t drink it – make a litre bottle of water, cucumber and lemon and put that in the fridge – Boom there’s your new fix

  • Hypsibius

    I recently gave up Diet Coke for 5 weeks as part of the Whole30 challenge. Before that, I probably had one or two cans a day. Honestly, as part of a careful, restrictive diet of meats, veggies, fruits etc… sometimes Diet Coke can be a nice treat and it actually provides satiety and can cut down on a craving for something sweet. In terms of health or mental clarity or weight loss, I personally haven’t noticed any negative effects from reintroducing some Diet Coke in moderation. Do I think it’s the best thing in the world for me? No, probably not… but if you’re dieting and hitting the gym regularly I don’t think you need to fear that Diet Coke is going to derail your progress — it won’t.

    OH! And I should add that I’ve found the flavored La Croix (orange or grapefruit) to be a much better choice when you’re looking for a replacement. I drink far more of that than Diet Coke now.

  • jonos

    I went from reg coke to diet coke and lost 15 lbs without barely any workout but now that i am working out i see that soda is seriously bad for you.but if you need that 1 or 2 a day preferably 1 do it with a diet

  • jonos

    Wtf. Whats your problem. Drinking what makes her feel better isnt pathetic, the fact that your judging someone who probably didnt want to say that in the first place makes only you pathetic my friend

  • jonos

    Thats regular coke that does that not diet lol

  • jonos

    Did you say porrage? Lol