How can I get my family off my back about my weight loss?

Hey there. So here's a little background info. I'm a 5'7" 20 year old female. Back in June 2010 I was 197 pounds and was sick of being overweight. I would pig out on basically whatever I wanted and it showed. So I decided to start eating healthier and exercising. I didn't really tell my family much about it because I didn't want to admit to them that I was unhappy with the way I looked. Anyways, I started working out consistently ever since and have be eating a reduced calorie diet with lots of lean meat, fruits, veggies, water etc. I'm not starving myself, I just eat a reasonable amount of food now compared to how I would gorge myself before. I currently weight 149 pounds (and am thrilled) but I'm running into a problem. My parents ( who I still live with as I commute to University) are convinced I'm like underweight and skin and bones now. They comment all the time about how I don't eat enough and how I shouldn't lose anymore weight. We fight about it on a weekly basis. I promise you I eat enough (about 1500 calories per day of healthy food) but they don't see that because I eat numerous small meals and snacks through out the day. I bought myself a new pair of pants (size 6) because my other pants didn't fit and my parents threw a fit (mind you, they are both quite overweight and lead very sedentary lifestyles). My goal eventually is to be down to about 130 pounds and to be very toned. I have explained to them on numerous occasions that my weight loss has been a result of just eating healthier and exercising, but I guess they have it imprinted into their mind that the only way to lose weight is by starving yourself, therefore I must be doing that. I don't know. Am I being unreasonable here? I've been trying to do everything the healthy and right way to get down to my desired look but it's really tough with my parents breathing down my neck. How can I get them to support my new healthy lifestyle?