Hi Jenn
First congratulations on your weight loss.
You must feel fantastic about this accomplishment.
So you have another 20 pounds you would like to work on. At 150 pounds you would have a BMI of 22.1 which is within a healthy range. However, as many of us know the BMI doesn't give us the whole story. If you have the opportunity it will be helpful if you can determine your body fat percentage.
The body fat percentage will be a great way to determine your end weight goal. It is also helpful to have this information when you wish to determine your maintenance calories as well as the number of calories you should reduce from your maintenance calories in order to continue to lose weight. (stay with me here)
Many scales provide a body fat measurement through bioelectrical impedance or you could just use a hand held body fat analyzer. These are not perfectly accurate but pretty close when done correctly.
I have also provided a link that will allow you to approximate your body fat percentage based upon tape measurements of your neck, abs, and height.
http://www.linear-software.com/online.html
Once you have your body fat percentage, you may determine the amount of pounds of fat you have vs. the amount of lean muscle you have.
current weight x bodyfat % = pounds of fat
current weight - pounds of fat = lean body mass
Now that you have your lean body mass you may take this information and determine your maintenance calories. Chances are your body fat is greater than 21% right now. If this is the case, you multiply your lean body mass by 13 to determine your maintenance calories. If your body fat is less than 22% then you would multiply this by 14 instead.
For example, at 21% body fat I have about 103 pounds of lean muscle mass
103 x 14 =1448 maintenance calories. Now, if I wish to lower my current weight I reduce my intake about 200 calories each day. I would also attempt to burn off approximately 400 to 500 calories through my workout. This would allow me to lose at a rate of about a pound to a pound and half a week.
One of the other things I would suggest is that you make sure you are lifting rather heavy (for you) at least one day a week. This will ensure that as you continue to decrease the amount of body fat your lean mass increases or at least stays the same.
It's a lot of information. I know. However you really seem to already know how to do this: clean eating, strength training, and cardio (if you are doing only 20 minutes...make sure your doing interval training
)
I have also provided a link that further explains how to determine caloric intake for fat loss based upon your lbm:
http://www.articlesbase.com/weight-l...at-744085.html
You are doing just great.
You've already done so much. Don't become discouraged with the last ten to fifteen or twenty pounds. It's a lot more difficult now because your body is efficient and it's on to you
But with consistency you'll meet your goal.