system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When looking at the nutrition facts on a food, what am I supposed to be looking for that would indicate it as a healthy food?
gpt
It's a bit of a moving target, since you need to look at *everything* you eat, not just one item. Furthermore, your requirements will be different depending on age, gender, type of activities, and many other factors.

As a rule of thumb, though, check the ingredients and make sure it's not mostly junk. Anything that's mostly sugar, for example, is out. Anything with a lot of sodium is probably out too. A lot of things that people assume are healthy (e.g., cereal) are really just sugar delivery vehicles.

After that, try and find out what *your* nutritional requirements are. Once you have that, you can look at calories and make sure you're not far exceeding your needs. You can also look at vitamins and all the other good stuff. 

The real trick, though, is *moderation*. If you generally eat healthy and don't have other health issues, the occasional soda (while unhealthy) won't really hurt.