Diet Soda Health Risks: Why Your Daily Soda May Be Sabotaging Your Weight Loss

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Diet Soda Health Risks

You switched from Coke to Coke Zero when you started your weight loss journey. But is diet soda the reason you’re not seeing the results you expected?


  • Head-to-head, people lose more weight drinking water than diet soda
  • People more than make up for the calories saved when switching to diet soda by overeating calories at meals
  • No-calorie sweeteners can rewire the brain’s pleasureable reponse food
  • The insulin response to no-calorie sweetend beverages is the same as with sugar-sweetened beverages
  • No-calorie sweeteners are incredibly sweet, and they make healthier foods taste bland

If you’re trying to lose weight, it may be a good idea to avoid diet sodas.

In fact, diet soda consumption has been shown to lead to weight gain. And not just in one small study. There is a large body of evidence that shows that diet sodas are linked with weight gain.

There’s also evidence that diet sodas might sabotage your weight loss efforts by increasing hunger or disrupting your body’s natural ability to regulate calories.

Research even shows that drinking diet beverages may cause metabolic syndrome – a combination of diabetes, high blood pressure, and obesity, which makes it harder to lose weight.

In this article, we’ll take a closer look at diet soda health risks and why you might want to avoid drinking them if you’re trying to lose weight.

Diet Soda Health Risks Introduction and History

Diet Soda at Lunch

You’re sitting at your desk, diligently working on a project for work. Every day you walk to the break room and grab a diet soda from the fridge.

In fact, you’ve been drinking them exclusively for months now because it’s said artificial sweeteners are better than sugar when it comes to weight loss.

But your weight loss has stalled. In fact, you’re constantly starving an hour after your afternoon diet pop, and all you want to do is binge out on the staff room’s latest white cardboard box of deliciousness.

You go home, hop on your scale, and after months of being a ‘diet’ drinker and…nada! No drop!

Diet sodas became popular in the 1980s as a way to combat obesity. At the time, diet sodas were marketed as a healthier alternative to regular soda because they didn’t contain any sugar.

You still got your favorite sugary drink but without all those empty calories! Win-win.

Unfortunately, the introduction of diet sodas may actually have made the problem worse.

While more studies on humans need to be conducted, there is a large enough body of evidence showing that diet sodas may not only cause weight gain but also raise the risk of some diseases.

In fact, diet soda can be linked to metabolic syndrome, a combination of diabetes, high blood pressure, and obesity that makes it harder to lose weight. (1, 2, 3)

The animal agriculture industry started giving non-caloric sweeteners to livestock in the 1950s because it was so good at causing weight gain. This dramatically increased their profits since they got faster weight gain, more pounds on their animals, and on the cheap. (Greger, 2019, p. 168)

But we’re not livestock. What does the research say about actual people?

Well, let’s take a look.

Your Brain Wonders Where the Calories Are

When you eat foods that have calories your brain gets a signal. You enjoy a soft drink with 140 calories and your body handles the calories as normal.

But when you drink the diet soda your brain gets the same signal but is confused as to why it isn’t getting any actual calories. (4)

Researchers noticed this and wondered how that would affect food choices.

Turns out participants that drank diet soda ended up eating more calories at their next meal than participants who drank regular soda or water. (5)

The sweetness in the diet soda may actually trigger your brain to expect more calories to come. When the calories don’t follow as expected, your appetite ramps up and you eat more.

These results are consistent with brain imaging studies. Regular consumption of artificial sweeteners can actually alter the reward pathways responsible for the pleasurable response to food. (Greger, 2019, p. 170)

This isn’t a big deal if you are meticulously counting calories, maintaining your calorie deficit.

But you may be fighting an uphill battle. The diet soda may actually be causing additional cravings, telling you to eat more food, and making you feel less satiated and satisfied.

All of this can make it harder to stick to your diet.

24-Hour Insulin Response is the Same

We assume that by drinking diet soda we won’t have the same blood sugar and insulin response as with sugar-sweetened drinks. (6)

Researchers thought the same but found that over a 24-hour period, there was no difference in total blood glucose and insulin between regular soda and diet soda drinkers. (6)

But that doesn’t make sense. The group that drank sugar-sweetened beverages had 16 more tablespoons of sugar than the group that had the non-calorically sweetened? Shouldn’t their blood sugar be much higher?

When you drink a sugar beverage your blood sugar rises. Your body releases insulin to move sugar to where it needs to be.

When you drink a diet soda, there’s no insulin response (at that time, anyway) because there is no rise in blood sugar.

So far so good.

What researchers found, however, was that at the next meal, people who drank a diet soda had a higher than normal insulin response to their meal. (7) The extra insulin in your system means that your blood glucose can drop. Low blood sugar makes you crave extra calories, especially carbohydrates, to level your blood sugar back out.

Then you end up eating extra calories to level your blood sugar.

So you end up causing the same total blood glucose and insulin response either way, and you may actually end up eating more calories than you would without the diet soda treat.

Insulin is also both anabolic (helps with building muscle) and fat storage promoting. Researchers with the San Antonio Longitudinal Study of Aging found that drinking diet soda leads to long-term rises in abdominal obesity. (8)

And, diet soda has long been recommended to children with Type 1 Diabetes (T1D). But all of these findings are making even the American Diabetes Association question this practice.

A recent article in the Journal of the American Diabetes Association highlights a study currently taking place that will conclude in March of 2022. The rationale for the study is that low-calorie sweetened beverages may “worsen glycemic control and exacerbate cardiometabolic health among already at-risk children with T1D.” (9)

People Who Drink Diet Soda May Eat More Calories On Average

Researchers compared people drinking low-calorie sweeteners, sugar-sweetened beverages, of unsweetened drinks. (5)

They found that those drinking regular soda tended to choose more unhealthy, sugary snack foods and were less satisfied with sugar-sweetened snacks than both of the other groups. (5)

In other words, drinking diet soda made them crave sugary foods more often than others and they were less satisfied with the sugar they received. (5)

People who drink diet soda end up eating more during their meals than those who drink sugar-sweetened sodas or water. (7)

The energy ‘saved’ from replacing regular soda with diet soda was “fully compensated for at subsequent meals.” (7)

Even though they were drinking 140 calories less by choosing the diet soda, they ended up eating the same amount of calories at the end of the day.

If you’re trying to lose weight and you think that drinking diet soda instead of regular will lower your calorie intake, this may explain why you’re not losing the weight you want to.

And if you are counting calories, diet soda seems great because it doesn’t add calories. But it may make you crave sugary, calorie-dense foods, making it harder to stick to your diet, maintain your calorie deficit, and make you not feel as full.

You Reward Yourself for Good Behavior

You Reward Good Behavior

Most people don’t think much about why McDonald’s has salads. Everything McDonald’s does is well researched and designed to make a profit.

McDonald’s tested adding salads to their menu around 1986. What they found was that burger and fry sales increased with the addition of salads!

People who typically avoided McDonald’s because they were trying to make healthier choices, decided to stop in because they could now get a salad.

But people didn’t buy the salad! When faced with the option, people chose the tastier burger and fries instead. Their rationale for changing their mind once they got inside the restaurant? Just this once. I’ll have the salad the next time.

The same thing happened with diet sodas. People purchased more food when they ordered diet pop than when they ordered the sugar-sweetened version. Again, their rationale was that they were being good by choosing the no-calorie version, so they could reward themselves with a little more food.

But not you! You’ll drop the calories by choosing the no-calorie version, and that will help you maintain your calorie deficit.

Good on ya!

Most people don’t. So if you notice that you’re making choices that aren’t helping you move toward your goals, your cravings are getting worse, or you find yourself overeating when you have diet soda, maybe try and choose water instead.

* Update: McDonald’s removed salads from their menu in June 2020 due to the Pandemic in order to streamline their menu. They have to purchase different lettuce than they do for their burgers, and during the Pandemic this cut into their profit margins.

Diet Soda May Make Healthy Foods Taste Bad

Diet soda can make healthy foods like vegetables taste bland

Your taste buds can and will change if you give them time. On average, it takes about two weeks.

Eat broccoli every day for two weeks and it will start to taste better.

But maybe not if you are constantly feeding your taste buds, hyper-sweetened artificial sweeteners.

Constantly giving yourself sweets only makes you crave more of them.

And it makes healthy food taste bland.

Drinking Water Instead of Diet Soda May Lead to Greater Weight Loss

drink water instead of soda

Researchers didn’t control for calories, just whether or not they drank soda or water.

During a weight reduction program, 81 overweight and obese women with type 2 diabetes who usually drank diet soda were assigned to either switch to water or continue drinking their favorite diet soda five times per week after lunch for 24 weeks. (10)

The group that drank water lost more weight. (10)

And that’s kind of the point! Both beverages are zero-calorie, so it shouldn’t matter and weight loss or gain should be the same.

But as we’ve discussed, diet soda causes an insulin spike during subsequent meals, and people who drink diet soda tend to make less healthy choices later on.

What Should You Do?

This is such a personal question that is hard to answer, but here are some tips that may send you in the right direction.

Assess how many diet soft drinks you are having.

If you’re only drinking a couple of cans a week, enjoy them and be aware of the possible side effects we’ve talked about.

Drinking one can a day? Again, be aware of possible side effects, especially overeating at other meals or not feeling satisfied with the foods you’re eating. And try to cut down to one can a few times a week instead of every day.

Drinking multiple cans a day? Try cutting out one can a day. Go from three down to two. Then from two down to one. One way of doing that is to only drink 1/2 of one of your cans and then the other half later. You still get three diet soda drinks a day, but you cut down by one whole can.

Drink Regular Soda

Yes, you’re going to drink about 140 more calories by making the switch. But the research says that you will feel more satiated with the foods you eat. So drink the real thing, count the calories, and feel more full at your meals.

Drink More Water

Even if you don’t cut down on how many cans of diet pop you’re drinking, drinking more water tends to lead to healthier choices overall. And since you won’t be as thirsty, you might not reach for as many diet sodas as normal.

Hit Your Sweet Tooth With Fruit

I have a sweet tooth. Give me sugar and I will until I’m sick.

But I can hit those same pleasure centers with sweet-tasting fruits like berries, mangoes, and melons.

If you struggle like I do having sugar around, try and get it out of your house. Stock up on fruit and start having those when you feel the need for something sweet.

Eat fruit to hit your sweet tooth

Diet Soda Frequently Asked Questions

Will I lose weight if I stop drinking diet soda?

Losing weight requires that you maintain a caloric deficit by eating fewer calories, on average, than you burn in a day. What you drink is just one part of that balance. However, studies show that people who drink water instead of diet soda lose more weight on average.

Is diet soda bad for weight loss?

Diet soda can make eating health-promoting foods more difficult by making them taste bland, and can cause cravings for sugary foods. When you drink diet soda your pancreas releases insulin in response to the sweetness. But since there is no sugar (calories), your blood sugar can drop, making you crave additional calories from food.

Diet Soda Health Risks Conclusion

If you’re meticulously counting calories, this isn’t a big deal. Unless drinking diet soda is causing cravings that make maintaining your calorie deficit unachievable over the long run.

Drinking diet soda may lead to weight gain and cravings for sugary foods. Diet sodas are calorie-free, but they can cause insulin spikes during subsequent meals that make it harder to stick to a diet.

Drinking diet soda instead of regular is not an effective way to lose weight or maintain healthy eating habits long term. If you’re trying to cut back on diet drinks, try drinking less sugar-sweetened beverages in general.

Or switch from diet pop entirely and count the calories! The choice is yours!


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  2. Crichton, Georgina et al. “Diet Soft Drink Consumption is Associated with the Metabolic Syndrome: A Two Sample Comparison.” Nutrients vol. 7,5 3569-86. 13 May. 2015, doi:10.3390/nu7053569
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  10. Madjd, Ameneh et al. “Beneficial effects of replacing diet beverages with water on type 2 diabetic obese women following a hypo-energetic diet: A randomized, 24-week clinical trial.” Diabetes, obesity & metabolism vol. 19,1 (2017): 125-132. doi:10.1111/dom.12793
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  15. Greger, Michael. How Not To Diet. Macmillan, 2019.

*Author's Note: The content on this website is meant to be informative in nature, but it should not be taken as medical advice. The content of our articles is not intended for use as diagnosis, prevention, and/or treatment of health problems. It's always best to speak with your doctor or a certified medical professional before making any changes to your lifestyle, diet, or exercise routine, or trying a new supplement.

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Matt Walter, CHN, M.A.T
I studied Food Science and Human Nutrition at Washington State University and interned as a Strength and Conditioning Coach for the WSU football team. I am a Certified Holistic Nutritionist and former personal trainer and competitive CrossFit athlete. My mission is to make embracing and adopting a healthy vegan lifestyle simple and fun!

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