I agree that you are probably undereating. If you are too concerned about ass-growing to eat 1800 calories every day, at the very least eat that on lifting days and see what happens.
BTW, I eat between 1400 and 1800 calories on most days. I don’t bother with percentages. I just eat pretty much the same stuff every day and it seems to work for me. The foods are:
Breakfast = 1/2 cup oatmeal cooked in one cup of water plus some salt and a glug or two of milk or almond milk, then to the cooked oatmeal I add some frozen blueberries, a scoop of plain protein powder (not sweetened), some more milk to incorporate the protein powder, a bunch of cinnamon and some slivered almonds.
Snack = a banana and maybe a few almonds
Lunch = lean protein (turkey or salmon or 2 hard-boiled eggs), salad or veggies, a pear or apple
Snack = greek yogurt
Dinner = lean protein (steak, poultry, fish), salad, maybe some sprouted wheat bread or a sweet potato
Post workout = half scoop of Surge Recovery (its way too sweet for me to drink down a whole scoop)
Most days I might have a treat like a small xmas cookie (like today!) or some dried fruit or cheese. On weekends, I will go out to eat and (within reason) order what I want for a meal or two. I generally don’t drink any calories, but I might have one alcoholic drink on the weekend.
I’ve eaten like this for a few years and have been able to maintain my weight within about one pound above and below my target weight.
Hope that helps.
I think it’s estimating your calories just fine. Your body needs a few days to adjust to this influx of food. If you’re worried about throwing your calories up to 1800 a day, cycle it like kimba suggested. It keeps your body guessing and allows you wiggle room with your food choices.