"Clinically obese" means having a BMI of over 30. If you're six feet tall, weighing 225 means you're clinically obese, whereas weighing between 185 and 225 classifies you as "overweight" (BMI between 25 and 30). So, yes, losing less than 50 pounds can easily mean the difference between "obese" and "normal weight."

Some definitions of "obese" are literally being 50 pounds above your ideal weight

A 5'5" woman is clinically obese at 180 lbs and hits normal weight at 150. It's definitely possible for 50 lbs to be the difference between obesity and normal weight? I'm not sure where this train of thought's supposed to be going.

OP never mentioned her weight before and after, therefore, there is no reason to tell me about what the definition of obese is. If her friends didn't notice, I assume that she was quite obese.

There's that word... ASSume.

Exactly. People are confusing "clinically obese" with "morbidly obese." Clinically obese generally equates to ~50+ pounds over a normal weight limit for your height and muscle composition. Morbidly obese generally equates to ~100+ pounds over a normal weight limit for your height and muscle composition.

I think this is most likely what happened. Op, you said they haven't seen you in a long time, so there's a chance they just thought of you as smaller then you were. There's also the huge possibility that you had gained some weight in the years they hadn't seen you (let's say 20lbs in 2 years) so to you, you have lost 50lbs, but to them you've only lost about 30. So if you weighed around 150 when they last saw you, then gained 20 more in the (let's say) 2 years you hadn't seen them, then you lost 50lbs total but only 30 since the last time they saw you. Either way, you lost a lot of weight and got to see some old friends, so congrats on all of it!

On the other side there are lots of people who are really ill and get complimented for their great weight loss. It's a sensitive topic. I always get a mix between "too fat" and "anorexic" while only changing a little bit in between a 10 pound interval.

Or they were just unsure how to broach such a sensitive subject. Just because someone doesn't act the way you expect them to doesn't mean they are jealous. What if they are already at a healthy weight? What's to be jealous of?

I was just trying to make OP feel good about themselves. Calm down

I think it's pretty normal to want people to notice and acknowledge your accomplishments. Sure, it's healthier to let go of what other people think of you, but most of us still appreciate it when people compliment the results of hard work.

Of course it can be just 50 pounds. When I weighed 180 I was clinically obese. Losing 50 pounds would have put me in the "healthy" range for my height on the BMI scale. Now if someone tips into the moribdly obese range, then yes, 50 pounds wouldn't cut it no matter your height.