nutrition question

I have a nutrition question. My nut wants me to eat 900 calories, around 100 carbs, and 25 grams of fat. I still have been having trouble reaching those goals. But my question is on days that I am doing intense exercising (spin class and weights) I should be eating more right? I have been tracking my food on my fitness pal and on days that I do spin and weights it gives me extra calories and fat. Do I eat them or do I listen to what the nut told me? I am a bit confused? For example, i started planning out my meals for tomorrow and added in my exercise for tomorrow and myfitnesspal bringing my total calories up to 1400 my fats up to 38 and my carbs up to 157. Sorry for all the questions. I just dont want to mess up. My nut told me that If I got close to 40 grams of fat or higher that it would slow down my weight loss...can anyone shed some light and help me...thanks:-)

100-157 grams of carbs seems like a lot to me. Try to pay more attention to the protein you are getting and the calories, fats and carbs will automatically go down.

 I track on myfitnesspal too and usually just keep to my normal calorie limit. With the extra calories burned, they just become kinda bonus if you get to them.
 As you're really early out, don't sweat trying to get to those 900 calories too much. Great if you can, but don't beat yourself up on days you can't. Most important is getting your protein in! 100g carbs is way higher than my program allows, but every program is different. 

Assuming your surgery date is correct, I am surprised you would be eating that many carbs if you are eating all your protein requirements in 5 or 6 meals a day.

I have never counted fat grams and find that if I eat protein first,  min 80 - 100g per day, the carbs will take care of themselves.   Most of us find that it's the carbs that do us in weight loss or maintenance wise and not fat ...

I also only started checking calories once I was into maintenance and I had to watch what I ate a bit more ie, years 4 to 5!

I usually don't get near that amount in carbs unless I drink a lot of milk that day because things were tasting weird and what not. Milk is easy for me to drink and has enough protein if I drink enough. Thanks for saying that you never counted fat grams that makes me feel better.