Calorie count and maintaining question

I'm 42, weigh c177 pounds, and have a body mass index of about 23.4.  My body fat is 15% +/- 2%.

Apparently, if I were lying in bed all day I should be taking in c1800 calories, and based on my activity metre, I should be burning c2400.

Now, just because I know there might be some slight slippage, I have been very carefully weighing exactly what I've been eating for the past week.  On balance, I'm getting c1800 calories (or at least that is what comes out).  However, I've been stuck at exactly (+/- 0.3 pounds) the same weight for the past week.  OK.  So let us assume that I've been under-reporting what I ate.  But still, shouldn't I have lost some weight?

(I'm not trying to lose any weight at all, just trying to figure out my maintenance calories and stuff).

My exercise is a combination of light cardio (brisk walk in the morning to work) and light weight lifting.  Over the past week, I got 48% of my calories from fats, 32% from protein, 4% from alcohol and 16% from carbs.  A typical day will be:

Breakfast: eggs, cheese, ham, milk, fruit (400-450 calories)

Lunch: steak, butter, mixed vegetables, fruit (550-650 calories)

Dinner: fish, avocado or a salad, olive oil, maybe some cheese, or some ham or something, an occasional glass of wine (400-650 calories)

I don't go below 1600 calories a day and I try not to go above 2000.  My salt intake is very moderate, as I prepare most of my own food.  Plenty of water, plus a little tea or coffee or maybe some diet Pepsi.

Am I just inputting the data incorrectly or am I doing something else wrong?

1st:  If your body fat is around 15 to 17%, then you are quite healthy in that regard.  I have been working really hard to try to get mine down that low and have not quite reached that point.

2nd:  What may have happened is that your body's metabolism slowed down, so even if you are exercising more, your body has decided it needs fewer calories to run it, such as when you are sleeping.  I would recommend, as I always do, that you make sure you A) drink a large glass of water before eating breakfast 2) eat a healthy breakfast with around 40-50% of your daily protein needs and 3) eat a series of smaller meals, such as 5 or 6 instead of 3 larger ones during the day.  The key is getting your body's metabolism up and running to start the day.  After exercising, a person should get some protein in such as from a few nuts or beans to help the body's metabolism.

3rd:  The body burns more calories to keep muscles rebuilt, so the more muscle mass you have the more the body needs to fuel that. 

Personally, I think you will be losing weight if you were to keep on the above regimen for a couple of months.  If, for example, a person were to only cut out 200 calories a day from his/her diet or exercise/burn 200 additional calories a day, over the period of one year, a person would lose roughly 21 pounds.  So maybe your weight loss is gradual and is not immediately showing up.  I frankly would think that you could be taking in 2200 calories or more with your activity level and not gain any weight.

OK, thanks.  I'll keep with the program then, and see if I can bump up my metabolism.  Thanks for the tips.