A two-year randomized trial found that diet drinks with aspartame, sucralose and acesulfame potassium matched water for weight loss outcomes.
https://www.foxnews.com/health/diet-soda-vs-water-study-reveals-which-beverage-better-weight-loss
https://www.foxnews.com/health/diet-soda-vs-water-study-reveals-which-beverage-better-weight-loss