I think if you review
http://www.mybodygallery.com/index.html you'll find that no one looks skeletal at heights similar to ours in the 155-165 range. In fact, many of them in our height range look quite good even into the 140 range.
It's an individual choice as to how much weight you want to/are comfortable with carrying.
My choices are based on (first and foremost) my discussions with my doctor, and my past experiences at different weights. I was married at 148lbs and I was NOT skeletal. Not at all. If fact, here is a photo of me at my wedding, in my size 10/12 dress.
Halls MD is one of the better calculations out there. He states:
Are you overweight? Maybe Body Mass Index says you are, but actually you are not. BMI can be wrong. Look at the weight percentiles, because they adjust for age.
The older you get, the higher your BMI is allowed to be. For example, in people over age 50, BMI of 25 to 30 is still normal and very healthy. I also believe the 45th percentile weight is a good estimate of your ideal weight.
It’s educated guessing, based on an mix of scientific data and some assumptions. The "halls.md v2" method cannot possibly be perfectly correct. To some people, when things are not perfectly correct, they are wrong. However, the WHO & CDC criteria are not perfectly correct either.
It also further states:
We avoid calling kids overweight, unless it is really obvious. Preserving self-esteem is also important, even for adults. If the overweight threshold is too low, it will label nearly 100% of the people who are truly overweight, but also falsely label MANY normal people too. (That’s what the CDC criteria does to adults). These "false positives" should be avoided, even if it reduces the number of "true positive" people labeled as overweight. Thus, the halls.md v2 criteria are designed to have higher specificity than sensitivity.
The halls.md v2 criteria don’t adjust for race or nationality differences. There is some published medical literature available on this topic and I may try to implement it in the future, if demand exists. Also missing is an adjustment for muscularity, so that body builders don’t get insulted when their BMI suggests they are overweight or obese.
After I decided to try to create my own BMI criteria, I realized that there are a lot of potential areas for improvement.
It's also one of the few BMI calculations that specifically adjusts for FEMALE height, not just a general height scale.
Another feature of the halls.md model, is an extra adjustment of the Overweight criteria based on a womans height. In Adult men, median Body Mass Index is stable ( horizontal lines ) at all heights from short to tall. But for Adult women, short women naturally have a higher BMI than tall women4. This is true at ages 30 or higher, even for slim (10th percentile) women. It is probably related to varying leg length. Therefore, the Body Mass Index calculator makes an extra adjustment for this factor.
So while BMI is never going to be a perfect way to assess weight, it's not terrible either. It is an excellent TOOL, not the be all end all. I don't allow it to determine happiness or success, but I do use it as a loose guide on my way to being a healthier person.