Definitely limit your refined sugars and white grains.
Also be cautious if your having soup for two meals. Most that are low calorie/low fat can also contain absurd amounts of sodium, so that is something to definitely look at when your reading the nutritional information on an item.
I can give you an idea of different things I eat for different meals that fill me up very nicely, and the calories of them. Maybe you'll get some ideas
Breakfasts:
1) 1/2 cup Fibre 1 Honey cluster cereal, with 1 sliced banana and 1/2 cup 1% milk. = ~276 calories
2) 1/2 cup low calorie yogurt with 1/4 cup granola cereal = ~250 calories
3) 2 pieces chicken bacon, 1 large egg scrambled, 1 piece whole wheat toast with 1 tsp of margarine = ~267 Calories
Snacks:
1) One piece of fruit = Most fruit ranges from about 60-150 calories
2) Fibre 1 or Kashi granola bar if I'm on the run = ~150 calories
3) 1 serving of baby carrots with 2 tsp calorie wise dressing = ~75 calories
4) Mott's flavored unsweetened apple cup with a piece of fruit = ~150 calories
Lunches:
1) Small kaiser bun with a slice of cheese and black forest ham = ~300 calories
That is pretty much all I can think of that is filling for myself and doesn't require a recipe. All my dinners are usually cooked with multiple ingredients and then I use the leftovers for lunch the following day.
Definitely load up on the veggies though, If your hungry between your meals and just can't wait to get to the next, try grabbing a piece of fruit, a small serving of lower calorie yogurt, an unsweetened apple cup, or some veggies to snack on. Most of those things range around the 50-100 calorie mark and wont hurt too much if you really need to have something