The Rabid Grammarian

In my pursuit of healthier living I've come across many many ideas. Since I have a pretty well developed bullsh!t detector I have a fairly easy time at negotiating the miasma of theories about health and weight loss. Through all of my research I've come to the conclusion that trying to lose weight generally ends in failure while adapting to a healthier lifestyle is generally successful and often does result in a loss of weight.
Often though, a healthier lifestyle (and I define this as adopting a whole-foods diet filled with plants-based nutrition and little or no processed foods and moderate daily exercise) doesn't result in that much weight loss and people feel that the whole process was unsuccessful. That's where the concept of Health at Every Size (HAES) comes into play.
We are a very image-dependent culture. Our media has generally shaped societies view of what is considered attractive. We've become a society where healthy people are considered overweight and near emaciated people have become an image of health. We've come to rely on image as a measure of health rather than actual health as a measure of health. Even the medical community has been tainted to a degree.
People can be healthy or unhealthy at a range of sizes. We are individuals and health is a very individual process. I have been overweight (or even obese) much of my life. I was generally very healthy considering. I was very active comparably and I had better blood work than people half my size. At one point a doctor I was seeing told me that she had to re-run my blood work because she didn't believe that it was correct. My blood work was comparable to a professional athlete's. I weighed 230ish pounds and was categorized as obese by BMI statistics. She was the first doctor who ever told me the results of my tests said I was healthy and didn't go on to tell me that I needed to lose weight. One doctor had actually said he was "positive" I would have diabetes, based only on my size and wanted to give me a pill before testing me.  After he read my stunningly healthy results (I had better labs than my very trim father) he still wanted me to diet.
I have always been moderately healthy. I say moderately because I didn't feel as healthy as my blood work had shown. Health is a complicated issue. It's not just how you feel, but also how you look (I think we can agree that someone with dull skin or such can look unhealthy) and there is also underlying health or unhealth you may not even know is happening. Health can be physical, emotional or both.
I truly believe in Health at Every Size, but with caveats. It's true you can be healthy at a range of sizes, but that doesn't mean that you will always be healthy and even if you are healthy now, it doesn't mean that you always will be or that you have a free pass to immerse yourself in unhealthy behaviors. I also believe that it really isn't healthy to carry significant weight on your frame, even if you exercise regularly, even if you're currently regarded as "healthy" medically. The human skeletal system is not evolutionarily prepared to carry such weight. Over time even a healthy person of generous size will start to have ill effects on their joints and in their skeletal structure. I'm not saying everyone is supposed to be skinny, I still think that there is a range of healthy size, but there is an upper limit of Health at Every Size. In effect, it's not Health at EVERY Size, it's Health at a damn bit larger range of sizes than the medical community and the media accepts, but there is a danger zone depending on your skeletal frame.
I've known far too many who use the Health at Every Size as an excuse to not change, demanding that everyone should just accept them for who they are. While that's true, it's not HAES, that is "Fat Acceptance," and it's abusing the HAES movement. Most of my experience with the Fat Acceptance movement doesn't focus on health at all. I'm also not suggesting that people of size shouldn't be accepted in society. If you eat a healthy diet and do regular movement/exercise and your medical tests show that you are healthy, fine, you can claim HAES. If you're eating junk food and the only movement you do with excitement is from couch to fridge and you're relying on pills to make you healthy, I don't care what you weigh or what you look like, you're just not allowed to hide behind HAES, in my opinion.
I live in a community where there is a lot of shaming if you want to lose weight, no matter the reason. Many of the people I know are Goddess sized and when I mention that I'm trying to lose some weight and return to my body's happy size/weight, I get "but you're perfect and beautiful the way you are" or "skinny women aren't attractive" or "bone is for the dog, meat is for the man" and other similar jests trying to dissuade me from pursuing what I consider a healthier lifestyle.

So the breakdown I guess is that not all thin people are healthy, not all larger people are unhealthy. There is a wider range of size at which people can be healthy and society and the medical community need to get a clue. While there are larger people who are healthy there are far more who aren't (but that doesn't mean a doctor should automatically think heavier = unhealthy) but even healthy larger people run a risk of musculo-skeletal issues in the future no matter how healthy or active they are because the human body does have a load limit, there is an upper cap that depends on your individual skeletal system and over time the circulatory system may suffer from needing to pump to a larger frame. Everyone should strive to be healthier, and some should strive to be healthier and thinner, though not everyone needs to weigh 115 pounds. Also, I guarantee if you switch to a whole-foods, 70%+ plant-based (and preferably organic) diet, tossing out all those processed products and non-food items (remember, food comes from farms, products come from factories) you will feel, look and be healthier. There's a reason the Standard American Diet abbreviates to "SAD."