system
Given the following post, respond as if you're commenting on Reddit:
human
How do gland problems stop people from losing weight?

If I burn 2400 calories in a day, but eat only 1900, why wouldn't the 500 extra calories just come out of fat like normal?
gpt
Yes.  But the signals being sent to the brain can cause over-eating or burn rate issues (imagine feeling sluggish after walking 5 minutes-- how would you burn 2400 calories?).  Metabolism (the body's natural burn rate) can widely vary based on age, gender and genetics (see Hypothyroidism).  So effectively in equation terms, yes, if you managed to burn 2400 calories and only ate 1900, you would lose weight; but easy burning is the pretty much the key glandular factor issue.