system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: how does drinking diet coke make me fat if it has zero calories and is a liquid like water? 

If you drink lots of water, isn't coke the same?
gpt
Basically the artificial sweeteners in the diet coke simulate insulin and/or sugar in your body, making you crave more sugar. Thus you eat more of other kinds of sugar, like cookies, chips, all your favorite carbs and other "unhealthy" foods.