people who DO NOT east back their exercise calories---

my wife seems to be having this problem shes 5' 2 '' and 138 she works out 30 mins 4-5 days a week cardio/arobic and has only lost 3 lbs in 5 weeks total calories in is 850-900 daily I wonder if she needs more?

Even someone who is smaller than average should not be under 1000 cals per day, and certainly not if they are exercising regularly. It is VERY difficult to ensure adequate nutrition (macros and micros) on less than that.

http://www.myfitnesspal.com/topics/show/186814-some-mfp-basics
http://www.myfitnesspal.com/topics/show/61706-guide-to-calorie-deficits

I work out just so I can eat more lol.

Haha, yep! That's my motivation for working out.

I'm 5'2 107 lbs and I eat 1800 to maintain.
So, yes, a taller heavier person than me CAN lose on 1800, especially if they are working out on some days to increase that deficit a bit.
Your trainer is smart. 1200 is ridiculously low for most people.

For someone who is obese or just starting out, 1200 is "ok" to try for a short amount of time for a jumpstart. But then you need to eat more. 1200 got me from 130-120, but then it stopped. I had to up it to 1500 to go from 120-110, then upped it to 1600-1800, depending what I feel like eating that day. I am now at 107.

The OP has VERY little to lose, and should have their goals set at 1/2 pound per week and should probably be eating between 1600-1800 a day to lose those last couple, and 1800-2000 to maintain.

so do you eat your exercise cals?

I eat within 500 cals of my TDEE each day.
See, I use the BodyMediaFit, so it is a different system.
If your MFP goal is set to 1 lb per week, then you are already AT a deficit of 500 a day. If you exercise, and DON'T eat them, you are increasing that deficit too large. If you DO eat them, you are keeping your deficit at 500 for the day.
BodyMediaFit tells me my total calories burned for the day, from midnight to midnight, just living my life...so I just eat within 500 of that, usually less, for less than a pound a week loss, and a few times a week I eat them all for NO deficit, as I am maintaining. But the couple of days with a slight deficit make up for the days someone decides we are going out for dinner somewhere naughty. It all evens out to maintenance...

I do not eat my exercise calories back. I eat 1200 calories per day. I have only been on this diet for exactly five weeks but I have lost 18lbs. It's possible the weight loss would slow down as so many people mention here, although I'm only 6 lbs away from my healthy weight (@ 10% BF).

I think it all depends on your individual situation. I'm a former athlete and basically ate well and never missed a workout for several years. I think in my case there is some sort of body memory or something. The past five years I have concentrated on other things and gradually starting eating more and did little to no exercise.

I'm 38 years old and 5'7" and my weight went from 146lbs to 174lbs, and BF from 8% to 20% over the course of five years. I want to get back down to 150lbs. I made a point to change my career and to start exercising. For the first 3 1/2 weeks starting on March 1 I reduced my food intake to 1700 calories and ran 3 1/2 miles, 6 days a week. It was hard to get started. I did not loose a single pound for almost one month and that was frustrating but I needed to just get moving. In fact, I think a real problem for a lot of people is striving to do too much to soon. I ended up with a stress fracture in my left heel!

I started MFP on April 30th and set my caloric intake at 1200 calories. I decided I wanted a big calorie deficit as long as I'm not tired or hungry. I estimated my BMR, and based on my new activity level I derived a daily calorie need of ~2300 calories. Since I felt healthy enough I really kicked into gear, and workout every day at between 500 and 900 calories per day. The stress fracture (painful!) was probably a blessing as I vary my cardio workouts between biking, boxing, and swimming (I had not been swimming in years...). In the past I would just run, but I feel better and have worked many more muscles than just running, and muscle groups don't get burned out. I also do a pretty intense free weight workout every other day for 90-120 minutes as well. I use a HRM and these calories also factor into my daily exercise calories burned, so it's not just cardio. At the end of the day I have an estimated calorie deficit of about 1200 calories per day, more or less depending on the amount of exercise.

My food intake is about 43%,14%,43% Carbs,Fat,Protein. So far, I am losing 3 1/2 lbs per week and I don't find myself tired or hungry, so I don't eat back any of the exercise calories. I have about 6 lbs still to loose, most exclusively a good size pinch right on the font of my stomach area there. I don't feel I've lost any muscle, although I've lost fat just about everywhere on my body.

One thing seems misleading to me if you are doing a lot of exercise. When you do an estimate of your metabolic rate doing normal daily things it may come to something like 1900 calories. Divide this by 24 and you could say you use 80 calories per hours during the day while not exercising. If you are exercising for several hours per day, say 3 hours, and using a HRM to record calories burned, then technically wouldn't you want to subtract those 80 calories x 3 hours from your calories burned? Since you are already documenting the calories burned during exercise, you're effectively counting calories twice for the same 3 hour time period. For example, in my case, I calculate my daily caloric needs at 2300 calories. However, when exercising for 3 hours and burning 700 calories I'm not also sitting around burning the other 240 calories at the same time, so when adding these calories back to my Food calories available in MFP, I would think I should really be adding only 460 calories (700 minus 240) to my Food Calories.

At the moment I try to, but I don't often get to that point. I just started (again) though. I know that for me 1200-1300 calories isn't enough long-term, but right now it's giving me that boost to see the weight falling off! However my biggest problem is that I don't eat enough - always has been. I find it very hard to eat enough calories without going over in one of the other limits - carbs or fat. Especially carbs. Loooove my carbs.

Most of the time I find myself looking for something to eat in the evenings to use up my calories, which is annoying.

Two big things regarding intake and exercise:

1) Most people trying to lose weight should be eating at a caloric deficit of (Maintenance - 500). People who are already low in bodyfat (15% or less) should be eating at (Maintenance*0.80) or even 0.90 to ensure they don't shed muscle along with fat. If you don't know what your maintenance number is you need to find this out pronto. Use the Katch-McArdle method, there are calculators online. You need your ACTUAL weight and ACTUAL bodyfat % for this. Ask your doctor or your gym. No BMI crap, do it right.
2) Your body eats fat, muscle, anything it can get its hands on for energy. If you are exercising and not eating back up to (M-500), you are actively telling your body to go ahead and not just burn fat, but take some muscle too. This is not just silly but potentially dangerous as you are actually getting weaker over time which inhibits weight loss. Eat your calories back. It's easy anyway - if you burn 400 Cals in the gym, have a protein shake and maybe some peanut butter on an apple within 90 minutes of getting home. Boom 400 Cals, and you did it while burning fat and maintaining muscle.

I don't see a point in burning 45 minutes worth of fat on an elliptical and treadmill, just to eat it back on. It's only ever made me maintain my weight, or gain.

If you're maintaining or gaining, you're eating up to or over what your body needs, as opposed to eating to a caloric deficit. You need to track your intake more closely.

For me it depends on how hungry I am. Last night I just was not that hungry, I ate my dinner and still had 211 calories left (after adding in my exercise in), I was not going to make myself eat if I wasn't hungry. Doing that is how I got to the weight I am. If you are hungry, use them, if not don't.

I totally agree with this!

Ok, I'm confused. Maybe I'll just eat half of my calories back, so I'm on both sides of the fence!!!
Like last night for instance, I had over 700 calories left, so I had some strawberries and frozen yogurt.
It was a nice treat and wasn't too fattening!!!

Ok, I'm confused. Maybe I'll just eat half of my calories back, so I'm on both sides of the fence!!!
Like last night for instance, I had over 700 calories left, so I had some strawberries and frozen yogurt.
It was a nice treat and wasn't too fattening!!!

Technically not "fattening" at all: if you are eating under your caloric needs, barring any abnormal medical condition (diabetes, for example), you will lose weight. It's that simple.

You'll lose weight for awhile, but then you'll stall out when your metabolism adjusts itself for the lack of calories.

So, what happens when you stall out? How do you jump start your metabolism again? (Sorry if this is a thread hijacking. I think this may have happened to me, and have been battling it for several weeks. )

It depends for me. I do calorie cycling as it seems to prevent my body going into starvation mode. That generally means that Mon - Thurs I won't eat them back and end up netting about 800 cals (although that isn't a problem for me). Fri, Sat and Sun (Sat is when I usually exercise the most heavily) I will eat a little higher and usually aim to net about 1600 on Saturday (given how much I run, that often means I'd have to eat about 2900 cals which I just can't do without feeling horrendous, so I might end up netting more like 1200 but I do have a piece of cheesecake to help me along!). So far, although I'm in a bit of a stall at the moment (because I took a few days off and had some booze over Easter), I've lost 40lbs so it does work.