What changing your diet can mean for health, and how diet soda can affect you

No matter what all the perky and smiling influencers on social media might be saying, take it from someone who has worked in the nutrition field for 40 years.

Making dietary adaptations is challenging for most of us. Some changes are easier than others. Many of my clients easily made the shift from whole fat dairy to reduced fat, lower sodium versions of prepared foods, and if eating meat picking out the lower fat cut. Much of my time has been spent looking for easier ways to improve the health of the change-resistant client.

This brings me to a presentation from the June 2025 American Diabetes Association scientific meeting. With about 15% of the adult population having diabetes and that number jumping to 29% for folks over 65, diabetes is a significant issue in the U.S. And not controlling blood glucose levels leads to numerous conditions you want no part of.

Presented at the meeting was the result of an 18-month small study. A total of 81 participants in a weight-management program, who regularly consumed diet beverages, were randomly assigned to either replace their diet drink with water or continue their usual intake of diet drinks. Many folks with diabetes, when being told they need to reduce their sugar intake, eagerly reach for a diet soda. This is totally understandable.

At the end of the 18 months, the participants who were drinking water showed a significantly greater average weight loss when compared to the diet beverage group. Diabetes remission was achieved by 90% of those in the water group compared with 45% of those in the diet drink group.

And if that weren’t enough, the participants in the water group also had improvements in triglyceride levels, fasting glucose levels and reduced insulin resistance.

This is a small and preliminary study on an important topic. I would guess we will be seeing more research on this topic, but this is the definition of a small change that can make a positive impact on health outcome. I’m not suggesting to never drink a diet soda, but making water your primary beverage is a healthy choice.

Sheah Rarback, MS, is a Dietitian nutritionist in private practice in Miami.