I wouldn't use weight alone, not even BMI, as people have different body proportions, fitness levels etc. regardless of weight.

I would use relative categories, mostly focused on their effects on daily life.

For 1 to 10 (I intentionally designed this system so that almost everyone fits into 1-6, ideal if you want to create fantasy scenarios with dice). I made this list with women in mind, but you can adjust them to men if you wanted

1: skin and bones, even those who prefer thin would call her too thin. Unhealthy and dangerous. Likely has an eating disorder.

2: thinner than average, but not clinically so.

3: most people would consider this to be normal, and strive to reach this weight if they differ from it.

4: chubby, considered above average weight by most people, but she can still hide the extra weight by carefully chosen clothing and camera angles.

5: definitely fat, and can no longer hide it. Still, the extra weight is not too limiting in most daily tasks and activities. If really attractive and has a great personality, might still be found desirable by those who aren't specifically into fatties (but they see her weight still as a major negative point)

6: obese, the weight starts to impose limits on many activities. People who aren't into fatties start feeling at least somewhat disgusted. Folds appear on different parts of the body regardless of posture, belly can firmly rest in the laps when sitting, some chairs become too tight, some difficulties when picking up things from the floor, basically the biggest size one can get without having either a severe eating disorder or being into feederism, and the biggest size most people will regularly see outside reality TV, or the Internet.

7. fatter than most things are designed for, cannot fit into small cars, into some restaurant booths, and even the largest clothes in supersize clothing stores start becoming too small. I consider the border betrween 6 and 7 to be the border between BBW and SSBBW.

8. still being able to care for themselves, but only with great difficulties. Standing up, or going up a single flight of stairs, or walking more than a few dozen steps, or just standing more then a few minutes are all very exhausting. Basically the biggest size one can have while being able to live completely independently.

9. requires a caretaker for everyday life, but is not completely bedridden. Still, getting up is difficult and might require help.

10. immobility.

It seems to me that people look much fatter in person than in pictures or videos. In person, even a 300lbs woman seems enormous, while many women fatter than them, seem relatively thin in pictures. And I'm not talking about those who are shy and try to look thinner in photos. Even proud, deliberately gaining BBWs and SSBBWs don't look really that fat in pictures.

I wonder why...

Where I live there aren't many really obese people around, so I have never met a 600lbs SSBBW in person. Still, I find it strange that those SSBBW seem in videos to be only as large as those of half their weight I did happen to meet in person.

Are there others with similar experiences? Or, are there some who experienced the reversed effect, seeing someone fatter in pictures than in person?

People are misusing the word "...phobia" so much that it started losing its impact. Many use it to describe anything from a mild dislike to just a failure to show open support.

Phobia is an irrational, uncontrollable fear. Which leads to panic attacks, clouding judgement. Which causes psychological trauma if you can't get far enough away quickly enough.

Phobia doesn't merely mean that someone doesn't like the exact same things you do or doesn't hold the exact same beliefs as you do.

I wouldn't even call it a phobia if someone really really hates something, if that something doesn't cause them emotional trauma just by being exposed to it.

Where I really love size comparison is not between myself and someone else, but between someone who looks really fat by herself, but would look small next to someone even fatter. For example, fantasizing about having an enormous girlfriend who has a fat sister or friend, who complains about her size, and then my much bigger girlfriend has fun that she is fatter but doesn't mind it.
Or better yet, getting to know a fat girlfriend who has even fatter sisters. And after some time, the sisters gain weight, and people think at least now my girlfriend won't look big in comparison.. and then she enters, much bigger, having overtaken them in weight and becoming the biggest.

There is also this thing called marriage, might prove useful, especially if you find someone with whom you can make it work.

Most profiles I've got such messages from, were obvious spammers. Probably others reported them sooner.

Full frontal nudity and explicit sexual acts are forbidden in the picture/video uploads, so I would tend to say no.

GMO and pesticide have nothing to do with each other. You can use pesticides on wild plants if you wish so. Or you can grow any plants, GMO or not, and not use pesticides (and be content with insects eating a portion of your harvest)

How would you feel if someone used strawman arguments to bash your beliefs and call them stupid?

Is this a trick question? How would it be possible for us to eat anything that's not organic? Is there anything besides salt which we eat and is not organic? And even salt is just a condiment, not food.

Wood is organic. So is plastic.