I worked with a very large woman, who probably weighed 350lbs. I began noticing her weight loss. When asked how she lost it, she said she substituted soft drinks with water. If I recall, the soft drinks she had drunk were sugar free. At that point, she had lost 80 lbs! (I only drink 1 can of coke zero per day, sometimes not even that. I’m not willing to give that up.)
All artificial sweeteners cause cancer in lab animals.