Attainable goal? Your input is greatly valued.

I know this is the most frequently asked question EVER.  So, here's the background.  I've lost about 50 lbs in the past year and a half.  I lost most of it in about 5 or 6 months.  My weight hasn't budged since February.  It's now August.  I was at the gym tonight thinking about where I've gone wrong.  I'm exercising now more than ever, but I'm being much less cautious than I used to be.  I think I'm out of will power.  So I thought about what losing the rest of this weight would really mean to me.

I am 24, 5'4, 174-6 lbs.  I have been eating between 1500-1700 calories in a day.  I run for 30 minutes three or four times a week, and usually walk at least 15 more minutes when I run.  On the days I don't run, I walk 30 minutes (those are my rest days).  I do light but vigorous work with weights 5-6 days a week. 

If I get serious, and by get serious I mean cut my calories back to the 1200-1400 range, do you think I could lose about 40 lbs by the end of December?

that would be 10 pounds lost each month, which is 2.5 pounds a week and safely you can only lose 1.75 or so since that's 1% of your body weight, which will decrease as you lose...so no i don't think you can and if you could it wouldn't be healthy. 

Congrats on your progress thus far!! :)

Well, at least I'll be closer.  Meh.  Impatience is a big problem here.

Keep in mind, Chrissy, she said year and a half, and most of it in the last six months  the OP could very well just be losing the right amount of weight if she lost 40 in the last six months and 10 over the previous year.

to OP:

I think you're doing fine, but restricting calories futher could run you in to the risk of your body hanging on to every calorie it's taking in.  If you're losing about 2 lbs a week, you're really doing fantastic :).  I'm down to 'that last 10 lbs' and it's really taking forever, but I've found in the last two months that it's really true that getting 8 hours of sleep a night does help.  A Lot.

The closer you get to your goal weight, the harder it will be, but so far, you really are doing a great job, I wouldn't suggest changing a thing until your weight loss starts to slow down - even then, don't cut your calories lower than 1500 while working out (my personal recommendation, others will tell you otherwise)

Best of luck : )

Change up your workout routine. Over time your body gets used to the same workouts and burns less calories. Mix in lifting or some other type of exercise and see if that helps.