Diet Soda And Weight Loss

The Study

The use of diet beverages to support weight loss remains controversial. In this interesting investigation that combined Harvard’s Nurses’ Health Study, Nurses Health Study 2 and Health Professional Follow-up Study, over 143,000 subjects had their diet and weight tracked for 28 years. The goal of this study was to see if diet soda helped people lose weight.

Here are some of the major findings:

-For every 4 year measurement period, subjects gained an average of about 3 pounds.

-Each 3 serving per week increase in diet soda consumption resulted in a small but significant weight loss during each 4 year measurement period. The association was strongest for the obese and heavy sugar soda drinkers.

-Replacing 3 sugar soda beverages with diet beverages each week was associated with a 3 pound weight loss every 4 year measurement period.

-This was the same as substituting 3 sugar soda beverages with water.

American Journal of Clinical Nutrition 2026; 123:101261

Take Home Message

This study shows that over the long haul, drinking diet soda instead of regular soda is associated with improved body weight. This may seem like common sense to a lot of you, but many researchers have argued in the past that diet soda does not aid in weight loss and may even result in weight gain.

No one is considering diet soda a health food and drinking it all the time is a bad idea. However, the occasional diet soda or sugar free treat will allow you to stay away from sugar and this will make weight loss a lot easier.