When I was 18 I was around 185-190, but I was in the best shape of my life and was lifting 4-5 times per week. I was much more muscular then than I am now. I went from 205 to 190 within the past few months. I have been on my wife's diet, and she has gluten/dairy sensitivities. I eat lean meat (turkey, chicken and fish) and fresh veggies for just about every meal, but will treat myself every once in a while with a nice steak. I'm not a big fan of sweets, so I don't think sugar is the issue. I'm just going to continue with my diet, drastically decrease my alcohol intake, and start to do more cardio. I'm also going to start taking Omega vitamins and whey protein. I think I can drop down to 175 if I really work hard. Given my body type, I think that's about as low as I could go without looking like I just crawled out of a POW camp.
Cutting down the alcohol is the hardest part of this. I usually have 3-4 drinks per night. Can't do that anymore.