Lol, I came across this thread when I typed "weird habits" in the search bar, looking for some thread I thought I saw before about INFJ idiosyncrasies.
I thought slant's post was funny, but aside from that I felt compelled to reply to this thread somehow.
As some of you have probably read someplace or another, I had some problems with body image and eating over the past couple years. I consider myself to be recovered now.
I think "thin" and "fat" are very subjective.
Just half a year ago I would have considered myself unbearably fat. My body was in exactly the same state it is now (perhaps slightly more bodyfat percentage than now, but in any case basically the same). I was depressed and extremely unrealistically self-critical.
I think because of this subjectivity, the words "thin" and "fat" used to describe peoples' body type are not useful at all, except in contexts which show a nature of making the individual's subjectivity/opinionatedness blatantly obvious. The range of "average" is too wide for people to be able to assess accurately with objectivity. Because of all this, I think only "healthy" or "fit", and "unhealthy", are useful terms.
Am I thin though? I don't know, you tell me. Some people have told me I'm thin, some have told me I'm average. I think the general consensus seems to be that my general shape looks average/thin, proportion-wise. I'm a little taller than average though. I'm exactly 5'7", or 171cm barefoot. I am a US size 6. This means that I'm "bigger" or have more mass than most females, because most are shorter/more compact. Compared to most north americans, I would be on the thin side. Compared to most Chinese or Japanese, I'd be on the chubbier side. But in general, compared to the entire world, I would consider myself to be "average".
I know that I am very healthy. My skin is basically perfect; my digestion is fine; my joints, gum/teeth, libido, appetite, etc, everything seems to be in working order (the one thing I've been having trouble with lately is sleeping early though, but I've had that problem all my life). I checked my blood pressure last week and I'm at 110/70. My resting pulse rate is 60; apparently that's basically athlete-quality.
I walk for 2-3 hours a day (not all in one go) because I don't drive and everything where I live is within walking distance. At my laziest, I'll walk for at least 1 hour a day. In addition to that I do yoga about once a week, and do something intense like dancing or running once a week.
I eat a considerable amount. That's what it seems like to me now that I'm not eating disordered anymore. Funny, because my weight hasn't even changed since my eating disordered period. I would say I eat now, on average, about 2000 calories per day, although I don't really take note of it anymore unless I think I'm going ridiculously over or under. I basically just eat whenever I feel like it. The one thing I've been trying out lately (for the past month or two) is avoiding wheat/gluten solids at all costs. My weight has seemed to have stabilized at ~137lbs because of this. I almost never eat fast food; maybe once every few months. I eat junk food (chips, chocolate) a couple times a week. I make sure to eat adequate carbs and fat. I try to eat more natural/raw foods. In general, I eat a lot of fruit, eggs (especially raw egg yolk), rice/potatoes and products of them. I don't eat as much vegetables as I used to, but I would say I still eat much more of them than the average Western person. When I do eat animal products, I generally eat mostly raw stuff - raw egg yolk, raw fish, rare beef steak. I eat much less meat than most people do. I drink a lot of iced coffee. I avoid chemical sweeteners, MSG, trans fat, and all those fun but unnecessary additives. I avoid canned and highly processed foods.
I have always experimented a lot with my diet and been deeply interested in nutrition science. I do not take any nutrition information out there without a grain of salt, whether it be from government-endorsed sources or alternative opinions. I don't believe anything - even if it seems to make sense. I have to try everything for myself first.
I've been normal a few times in my life, though. 
