system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do calories work? I bike 5 miles, I lose ~120-150 calories. But a small snack can be more than that?

Trying to lose weight and putting it in numbers is demoralizing. I've started riding a stationary bike for 5 miles and then doing minor weight lifting after and I maaaaybe lose 200 or so calories. Is that not a good exercise? I've been doing this almost everyday starting 2 weeks ago. But it's starting to feel useless if it's such a minor amount of calories burnt. Is this a good trend to continue? What am I missing?

Edit: everyone here has been incredibly helpful, and surprisingly consistent with one another. I feel much more confident about what I'm doing and what I need to do. Seriously, thank you all.
gpt
A lot of calories are already burned passively by the body. If you keep your intake at 1700-2200 calories a day (based on gender and height basically) those 200 calories account for 10% that wouldn't be burned otherwise. That really adds up over a longer period to get you to the weight you desire!

You're doing great and keep up the good work!!