Second Opinion: Sugar-free Drinks: Diet Aid or Diet Downfall?

Health Writer

Editor’s Note: This article is a part of an Op-Ed series, “Second Opinion,” where patient experts share their take on current research, news, and trends in health and medicine. The views expressed in this article do not reflect the opinions or views of

The consumption of diet drinks as part of a weight loss program has been debated for decades. If you ask dietitians and weight loss experts their view on diet soda, you will likely find some discord. Some of these professionals may themselves consume diet soda in an effort to lose weight or maintain hard-earned weight loss. Others may feel that diet soda is full of chemicals, making it a poor health choice. They may also subscribe to the notion that a diet soda habit may actually result in weight gain. I use solid science to help me make decisions, especially when there appear to be conflicting opinions on a weight loss topic. So is diet soda an effective tool or hindrance to weight loss?

Artificially sweetened beverages (ASBs) date back to around 1952 when the first sugar-free ginger ale, No-Cal, was made and distributed by Royal Crown Cola. The beverage was intended for people with diabetes and not advertised to dieters. Around the year I was born, 1958, Diet Rite was advertised to consumers as a sugar-free, zero calorie beverage. If you’re around my age, you know that Coca-Cola’s Tab was a homerun hit for the company. I had a Tab every day from the time I started my first diet at age 16.

There is conflicting research regarding the value and impact of diet drinks. One obvious problem is that many of the studies that suggest positive outcomes are funded by the beverage companies. Some of those long-term studies indicate that including sugar free drinks in a weight loss program results in a reduced intake of calories. That may happen because you typically “nurse” one or two of these drinks, so you are not eating and taking in calories while filling up with liquid, and because you have likely replaced full sugar sodas and beverages with a zero calorie beverage. In my case, I found that during my teen years, holding and drinking a diet soda or two definitely seemed to help me avoid extra calories and stay focused on my daily calorie limits.

The big question that most experts grapple with is whether or not a sweet, zero calorie drink seems to confuse the brain. The brain associates “sweet” with “energy calories.” So if you drink something sweet without a supply of calories, the brain may begin to issue signals that instigate hunger hormones. Those hunger hormones incite hunger, in an effort to capture those missing energy calories. Another debate focuses on whether specific sugars and zero calorie sweeteners elicit different brain and behavior responses. One study identifies differences between sucrose (table sugar) and sucralose (Splenda) suggesting that the brain can distinguish a difference while the conscious mind cannot.

This January 2017 PLOS commentary does a good job in summarizing the use of zero calorie sweeteners as a tool in the battle against obesity. Summary points offer that:

  • In early 2015, the World Health Organization offered revised guidelines on sugar, calling on governments to institute policies that limit consumer consumption of sugar and that regulate sales and use of SSBs (sugar-sweetened beverages)
  • The response of companies that produce SSBs was to invest in the formulation and sales of ASBs
  • There is no clear and consistent evidence that supports the role of ASBs in a weight loss diet or in preventing weight gain, so therefore they should not be recommended as an effective tool in weight loss or weight maintenance
  • More research is needed

So where does that leave us if we are trying desperately to lose weight and we find plain water a distasteful option?

I do believe that research confirms the link between sugary drinks and obesity. Sugary drinks are caloric, and they also lead to blood sugar elevations followed by severe plummets, which instigates hunger. Sugary drinks also alter gut microbes, which may additionally instigate obesity. On the other hand, recent research suggests that artificial sweeteners also alter gut microbe balance. So sugary or sugar free has a negative impact on your gut microbiota.

Diet soda and flavored waters (those not made with natural essence or a tiny amount of fresh juice) are also full of chemicals. I’ve abandoned my use of these drinks because of that and instead selectively drink select flavored waters (or I make it myself) and unsweetened teas. ASBs are also associated with a high generation of solid waste and cumulative environmental chemical pollution. If those discussion points are a non-issue for you, then I just don’t think there’s enough evidence to conclude that diet drinks “interfere” with dieting or weight balance. They may for some, but if you personally believe that they are a useful tool, I would be hard-pressed to argue, given what we know from science at this moment in time.

If you are a chronic or yo-yo dieter, then I would suggest taking a closer look at how diet drinks are affecting your weight loss efforts. In that case, they may be working against you and fueling a desire for more calories, possibly unconsciously.

I hope beverage companies and the research community will continue to study artificially sweetened drinks so that we can have clear evidence of the role that diet drinks should and can play in weight loss efforts. In the meantime, take advantage of some great options to replace sugar-sweetened drinks.

See more helpful articles:

Do Artificial Sweeteners Make You Crave Sugar, Gain Weight?

Want to Limit Obesity? Balance Your Gut Microbes