This seems to be a somewhat common issue when people initially switch to "healthy eating."
In my case, I just didn't trust that 1200 calories would get me through the day, so I'd be inclined to go really skimpy at breakfast and lunch, to be sure I had tons of "room" to tide me through dinner/evening. But then I'd end up with more "room" than I needed, and it could be actually difficult to reach that 1200! I dealt with this by taking a leap of faith and increasing the size of breakfast/lunch, trusting that 400-600 calories really WOULD be enough to get me through the evening.
The other thing that happened to me occurred when I switched from a heavily refined-carb junk-food diet, to eating much more fresh fruit and veg, complex carbs, good lean protein and virtually zero refined sugar/white flour. When eating really "junky" I ALWAYS felt sooooooooo hungry! It just seemed to burn off, leaving me ravenous, no matter how many calories I poured in. When I cut that out and ate properly, I didn't get ravenous anymore!
I would recommend, if you are "skimping" on early meals - stop that, eat a bit more at breakfast/lunch. If you are relying on "diet" versions of foods (zero-fat yogurt, lo-fat cheese, diet salad dressing, etc.) try using a bit of the "real thing" instead. (tastes better, is more satisfying, and see? you have room to "splurge" like that, right!).
If you don't make 1200 on ONE day, no big deal. But please don't make a habit out of it. It doesn't speed up weight loss, and in fact consistantly staying too far under your body's caloric requirements tends to backfire by teaching your body to become ever more efficient. You don't want that!
Goal 1 - break 200 (46 pounds lost)**DONE**
Goal 2 - leave obesity behind (BMI 29.9, at 185#) **DONE**
Goal 3 - BMI = Normal (154# or less)
| current weight: 172.5