I have a BMI of 17.9 (104.4 lbs), and I am working on getting back to my starting BMI of 17.2 (100 lbs). The last few pounds are the hardest to loose. In my personal opinion, while it doesn't produce the fastest results, eating at least 1,200 calories a day is the most beneficial in the long run. Sure, restriction does cause you to shed the weight, but once you resume eating more normal amounts you gain the weight back + some usually. I hit a plateau for quite some time. I started at 112 lbs, and got to 106 and couldn't get the scale to budge for about 2 weeks. I am finally starting to see results. Just keep it up, you'll be able to get there. It just takes some time.

My original goal was the weight that I was for most of my teens and 20s. The weight puts me at a BMI of 18.3. I've lost 8 lbs now and I have a BMI of 19.5 and a waist to height ratio of 0.423. These numbers are within healthy limits and I realized recently in looking in the mirror that I'm happy with my body now. Being healthy and happy are the most important things to me. I also recently had a scare where one of my periods lasted 21 days. I run long distance and my doctor told me that it was "due to being underweight from intense exercise." I'm not sure that assessment is so correct since I have a healthy BMI and I only run a few times a week, but just as a precaution I decided to switch to maintenance for a bit especially while training. When losing weight, I stayed under 1450 per day average each week for 6 months straight. I lost the weight slowly and safely without a plateau and even though I had days here and there that I went over, I had no problem meeting my weekly goal.

wassergottin, I do not work out a lot. To be completely honest with you, I have very little motivation to work out. Ever since I was little, I had been fortunate enough to eat whatever I wanted while still maintaining my weight. It wasn't until the last few years, that my metabolism has slowed down and I have gained weight. On days that I do work out usually 34-50 minutes on treadmill (4.0+), I do eat a little bit more than usual, but it all depends upon my hunger level. I do not believe in eating your calories burned back. This is of course a big debate on here, but in my opinion, you're defeating the purpose of working out if you don't produce a deficit. That being said, I think the best advice would be to eat healthy. If you do go over your BMR, then make those healthy calories (fruits, vegetables etc.). I don't think the number is as important as the quality and type of food you are eating (If that makes sense).

I am just a touch below the healthy range with a BMI of 18.2. I got there eating around 1400 calories a day (total - not net), and now maintain on around 2100 with more on the weekends. Doc says I'm healthy as a horse and is proud of my results.

I have seen others here who will swear up and down that you should only shoot for the mid to top of your BMI no matter what, and that obviously is complete horse donkey.