Weight loss calorie intake and running

Ive lost about 5 stone and started running again, however the charts i use tell me i need "X" amount of calories if i run "X" amount and i will lose "X" amount of weight...i often dont eat as many calories as im allowed , and im putting on weight , my measurements stay the same if anything the odd inch has come off my body but i weigh about 7 or 8 pounds more....can i assume that this is added muscle? 

I run 90% of the time 6 days a week with 3 to 4 10 mile runs filling in between with 3 or 5 milers and i never seem to eat morethan 1900 to 2000 calories. Im female and 58,.

Any advice gratefully recieved as i am in dread of putting the weight back on but i know i cant run on 1200 calories i just dont seem to have the energy if i try it for long. 

If you've lost size at the same time as putting on weight, I think it's safe to say that it's muscle not fat! Make sure you're eating enough - like you say, on 1,200 calories a day you're going to run low on energy pretty quickly.

Might be an idea to start a food & training diary, keep a rough count of calories and mileage and note how you feel (energy levels, mood etc) as well. In time you should notice a pattern and figure out a number of calories that suits your level of exercise. Don't worry too much about weight unless you feel your clothes getting tight, and if that happens you can make a small calorie adjustment downwards. If you're logging 40-50 miles per week, you should be able to keep the weight off no bother.

Thank you all for your advice and reassurance, yes i run a minimum of 30 and up to 40 or 50 most times, if i feel ive over done it one day i take it a little easier the next .

Yes i found 1200 calories was not enough. I was listless and rubbish .

Yep lost 5 stone after i stupidly let it pile on some years back , i did it by calorie counting and i still have a staple allowance of things i eat every day which is 1081 then anything else i eat on top i count and add too, its so easy to think you havent eaten much and then forget or not realise how these things add up.

My muscles feel realy hard in my calves and where i can feel thru the remaining fat (LOL) my thighs feel harder too, so logically it must be muscle but panic always creeps in !!

My heart rate resting is down to 55 or so from about 70 and my blood pressure is down too  

Thanks everyone for the help 

 a number of calories that suits your level of exercise. Don't worry too much about weight unless you feel your clothes getting tight

Great story! Well done on doing such a great job of losing weight and getting fitter.

Mind if I ask what your blood pressure was before and after? Just because my partner is overweight and on 3 different types of BP medication but consistently poo-poos all my 'notions' that losing weight would help to reduce it somewhat...

P.S. When you mention feeling your thigh muscles through the 'remaining fat' please remember that as a woman it's healthy to be carrying a small amount of fat, especially round your hips/thighs/bum. Too many chicks get sucked into eating disorders thinking that any fat is bad and that they have to lose it all. Please don't start thinking like that!