Problem with weight

Boy or girl? Twelve kilos in 4 months is a huge weight loss for a teenager especially when you weren't heavy to begin with. Do you have other health problems?

I'm a boy. I have no problems apparently.
The problem is that I am continuing to lose weight and it is evident from my physical appearance as well (e.g. ribs are clearly visible)

That's good to hear. If you have no health issues I wouldn't worry about it that much, humans are all different sizes. You didn't mention your height, is this weight appropriate for your height? You have lost a lot of weight recently. Did you put on some extra while you weren't playing and you've just returned to your pre-pandemic weight or is this lower?

The best way to add weight for a 16 year old guy is probably to hit the gym. Don't get crazy with it, find a program and stick with it week after week, slow and steady. Not only does muscle carry a decent amount of weight, but you will find yourself hungry more often. Be sure to eat sensibly. If you end up eating a lot of fat to get the protein to build muscles, you will not gain the type of weight you want.

The weight isn't enough for the height, according to what I have read online. I am 177 cm. Before the pandemic I weighed 60 kilos and I was 171 cm, 8 kilos more than now and 6 cm less. It's a little weird.

You are definitely on the light side. I'd try the gym and keep watching it. You can always talk to your parents/doctor about it.

Maybe you're going through a growth spurt? My husband grew 12" in his last year of high school. He went from being a little pudgy to being skinny. Have you seen your doctor about this?

Thanks for your suggestions!

if the not gaining continues, by all means speak to your doctor...

It might be, but I was already skinny before.

See your doctor, hon. We can only make suggestions. You very well may have a health issue that can be treated quite simply or this is a normal growth pattern. Either way, you'll feel better having seen a professional.

Eat 4 "big" meals a day.