I am a male 29,5'7 and weight 7 stone (9 now I know by the BMI's that I have taken that I am underweight by quite a lot.
The thing is I physicaly feel fine I do suffer from clinical depression but part of that depression is because I hate how I look.
The thing is if I am healthy in how I am should I just ease of the constant worry about putting weight on,it generates a lot of stress for me as it effects me social and especily how I think the opposite sex see me.
I know it's probably wise to work towards weight gain but if I can have the right to at least feel being underweight is okay (as I am not having any health problmes) then it's more likely I will put a little weight on.
Or is it something I should be worrying about and more importantly doing something about because I am a dangerous weight?
I am much older (nearly 60) and female so maybe hard to compare but I also have been skinny most of my life but always in good health. So, incidentally was my father (passed away aged 95) and my mother (passed away aged 99) and both sets of grandparents, of whom the "youngest" passed away mid eighties, so when people - either lay people or professionals - give me a hard time I cite the fact that I am fit, active, healthy, they can find little wrong with me, I have a family history of longevity which I suspect is at least partly due to not being overweight and my major problem with my weight is other people!
As you point out,fretting about trying to put on weight is counter productive. I know when I am TOO skinny and then I pull myself up and concentrate on putting on a few pounds, but I don't need scales or other people to tell me that. When I start to look gaunt then I focus on eating more but skinny is fine by me.
Of course I am much older and therefore I find it easier now not to give a toss about other people's opinions but I do remember being quite miserable about it when younger. I tend to shrug it off now and put it down to a certain envy perhaps and also that now the "norm" is what in my day would have been called overweight - we thin ones just stand out a lot more now!
Two provisos though and VERY important ones. Firstly, skinny doesn't always mean healthy. You need to be extra careful about monitoring your health and how you are feeling physically and if you do come down with some illness remember that you don't have much of a buffer and just a short illness can drop your weight down quickly from skinny to downright skeletal. So , as with any bodyweight,over or under, you do need to watch your health, be sensible about eating regularly and carefully and not be lulled into thinking that being thin will necessarily shield you from the ill effects of not eating or exercising well. I would therefore suggest perhaps get a thorough health check and if you come out ok -other than any "aesthetic" reasons for gaining weight - then keep on doing whatever it is you are doing until you have a good reason to do otherwise. Why fix something that ain't broken?
Secondly, it can be difficult to get full nourishment if you are also undereating and that in turn can be a factor in depression so you may want to think about whether you are emotionally as well as physically fit, being underweight.Perhaps just putting on a little weight may help that and it may also be wise to consider checking with your doctor for various supplements, just to "cover all bases".
That said though, if your health checks out, you feel well and can manage your day to day activities with no problems or fatigue then try to forget the snide remarks and comments. You are the way you are probably quite naturally. The only reason to try and increase your weight, in my opinion, is if it is affecting your health or if you personally would feel more comfortable about your appearance if you were to put on a few pounds. Other than that it really is nobody else's concern.
Oh. . . and the other incentive to putting on a little weight is that it becomes so hard to find clothes that fit! The market just doesn't seem to cater for this end of the spectrum. Not so bad when I was younger as I could always find clothes to fit in the teen section - not such a suitable option though now in my more mature years!
Anyway just my opinion as I have been through this most of my life and I do understand how incredibly frustrating it can get. Putting on weight is no easier than trying to lose it and as with losing weight, if you aren't doing it for health reasons or because it is what you (not other people) want, then it surely becomes much more difficult.