Not sure hun, we're going to need a lot more info than that to really answer that for you though...
How old are you?
What is your diet like?
Do you have any food allergies?
Do you exercise?
If you diet isn't that great, e.g. lots of sugar, refined wheat products like white bread etc, not much fresh fruit or vegies, it could be that your body FEELS chunky and sluggish from the inside (regardless of what you look like on the outside). Improving your diet and making sure you're well hydrated could make the world of difference!
My best friend has felt fat and sluggish and has had nausea for pretty much her
entire life (she's 29) and she only just found out that she's gluten-intolerant! Now she's on a gluten-free diet and feels amazing. The improvement in her inner health is astonishing
Exercising regularly (3-5 times a week) also makes you feel healthier from the inside, and improves your mood and confidence/self-image as well.
Rest assured though, you are a very appropriate weight for your height, and I'm sure you look very healthy. I dare say that if you actually lost any weight you'd start to look a bit sick/unhealthy
If you suspect these thoughts about losing weight are coming from some type of distorted body image kind of thing, that is a whole different ball game. If so, please feel free to PM me as I have been to hell and back with multiple eating disorders.
Be healthy and happy
