Not losing weight….eating too much or not enough?

could be that your excercise is building / toning muscle which will affect your weight loss, i went to the gym 5 nights a week for 18 months, never lost a lb but my body got more toned and i lost some wobbly bits

If you just started working out then you could be retaining water- I've had that happen and it's frustrating to be working hard and seeing no scale movement. That will come off. Also, if you're eating 1200 you should eat back at least half of your exercise calories. This will help you to not be so hungry. MFP does not figure those in when it gives you the calorie limit, which is why it wants you to enter exercise. Most people on here say that MFP overestimates calories burned, so the advice is to eat half or 2/3 back only. Sometimes that is the only thing that motivates me to exercise- I get to eat a bit more! And yes my experience is that I lose the most weight the first week and then go down to a 1 to a 1.5 loss from there on, however, I didn't start working out heavily at first. I was doing the Julian Michaels 30 day shred once and I got very discouraged because I actually gained weight after 7 days!! Then I learned that a lot of working out can make your muscles retain water at first so be patient with that.