Maybe this little chart will help with some ideas?
The quantities are for a serving:
Eggs, Cheese, and Dairy
Cheese, light or fat free = 2 oz
Yogurt, low fat and sugar free = 8 oz
Egg whites = 4
Eggbeaters = ½ cup
Cottage cheese, low-fat = ½ cup
Fish
Any fish or shellfish = 4 oz
Meat or Poultry
Skinless chicken or turkey = 3 – 4 oz
Lean beef or pork = 3 – 4 oz
Lean deli meat = 3 - 4 oz
Meat Substitutes
Soy chicken patty = 1
Soy burger = 1
Soy hot dog = 1
Soy cheese = 2 oz
Soy milk = 8 oz
Soy nuts = 1/3 – ½ cup
Tofu = 4 oz