Artificial sweeteners are 200–600 times sweeter than sugar. But unlike sugar, they don’t satisfy the appetite with calories, causing some people to compensate by eating more later in the day. There is also some research that indicates these artificial sweeteners actually increase your sugar cravings, leading you to eat more sweets/high-calorie foods. This can lead to weight gain and altered taste buds to sweet foods (what used to be sweet is now not sweet enough).
Blogs: https://nutritionhealthworks.com/nutrition-blog/should-stop-drinking-diet-soda/ & https://nutritionhealthworks.com/nutrition-blog/artificial-sweeteners-good-bad-ugly/