Why are diet drinks unhealthy? isn't a diet coke better than a normal one?

No: Regularly drinking soda has been linked to Non-Alcoholic Fatty Liver Disease, Diabetes, heart disease & metabolic syndrome. Other possible risks include: increased weight, decreased bone mineral density (BMD) obesity, erosion of tooth enamel, mineral depletion & dehydration. If it contains artificial sweeteners & is used daily, this is linked to a 3 fold ^ in dementia & stroke.

Both are very toxic: Pick your poison! There are significant health risks both regular and diet sodas. Artificial sweeteners like aspartame are very toxic, but so is the high amount of high fructose corn syrup in regular sodas. The best choice is to avoid both; kombucha is a good alternative. See https://tinyurl.com/hadj3ot and https://draxe.com/is-diet-soda-bad-for-you/