What's the disadvantage of being thin?

Yes, you are right that thin people often have problem with cold weather because they have less fat to maintain temperature of body. I think it is one of disadvantage of being thin. Thin people tend to have weak energy because they have less muscle.

I think you are right, I am also thin and I need to cover myself more in winter, but I prefer to be thin than fat. In summer you cannot remove the fat not to feel the heat.

Well it is not true that thin people have less health issues, I am very think and I still have health issues and I think I feel the cold more than a heavier person.

Many fat people are terrified of the cold too. I think fat or thin has no bearing on cold or hot tolerance. Fat or thin has nothing to do with health too. Many of my friends are much thinner than me, and yet they have high cholesterol and high blood pressure. I do not have this problem. Some of those who are fatter than me are always feeling cold in air conditioning room, yet I do not feel the cold at all.

being fat or thin, both have disadvantages. it's nice to be slim but not tatally skinny. thick is ok as long as you still have curves

I would venture to say that being thin is advantageous or disadvantageous based on the individual's own body mass and bone structure. If one is naturally thin without working at it (diets), then disadvantages are limited if any. However, in today's society there is tremendous pressure to be thin and this does create many disadvantages that show up over time. For example the danger of eating disorders are greater. In women of age being too thin lends itself to a sunken look and more facial wrinkles. And so many extremely thin woman look like boys in puberty. Then there is the resultant health problems that can come later as a result of starvation of food imbalance.

It is better to be in between,. Not to fat and not to skinny.

I think there are health disadvantages to being too thin or too large, it's best for a person to maintain a healthy weight...but also other things need consideration as well. Like, a person could be at a middle weight, but their body can still be lacking certain nutrients and they still need some things...so, just weight alone can be kind of misleading.