I actually don’t have a exceptional physical strenght/fitness, and a 1km walk is too long. I honestly have no idea why I have this “issue”, and it worries me. I mosty sit programming and watching Youtube, so either the brain or the occacional heavy use of legs burns it all. (I burnt 2kg of my weight while on a festival this year… Drinking beer and electrolytes… And my 2nd priority was to eat there. o__O)
The reality is that everyone’s metabolism is basically the same, unless they have a parasite or metabolic disorder. If it actually worries you, track your calorie intake exactly for a month or two.
If you’re taking in 3k a day and still losing weight, yeah, there’s something going on and you should consider asking a doctor.
If your definition of forcing yourself to eat is 1.5k a day you just have a low appetite. Enjoy?