Your daughter is trying to express her independence and as many have already said, this is common. Her growth rate is also much slower now. My 2 1/2 year old son used to eat eat eat and then it suddenly slowed way down. I mentioned it to the doctor and she said they aren't growing nearly as fast and actually need less. They also have different priorities at this age and playing comes first, before almost anything
in our house.
Foods that you could try, if you haven't already:
yogurt in different flavors - my son eats his yogurt with a spoon of the same color so lime is eaten with his green spoon, peach with his orange spoon, etc
milk with chocolate in it is fine, it adds very little sugar or calories if you use just enough to change the color of the milk - or Hershey makes a sugar free syrup if you're really concerned about that
fruit smoothies - we make these on the weekend and my son looks forward to them. 1 cup frozen strawberries, with about 20 or so frozen blueberries on top. Microwave for about 1 minute so the blender doesn't have to work too hard (now you don't need to add ice and water it down, your fruit is your ice). Add one banana, about 6-8oz of soy milk and a couple spoons of vanilla yogurt. Loaded with protein and calcium and healthy too. Our whole family enjoys!
black beans are a great source of protein and easy for kids to eat with their hands. Drain and rinse a can of beans and heat in the microwave about 30 seconds. Don't overdue it though as you may see whole beans in her diaper/potty.
Cheese rollups are a big hit in our house. Take one flour tortilla, sprinkle on some shredded cheese. Microwave about 20-25 seconds and roll. Allow to cool a few minutes or put in the freezer for a second as the cheese does get hot. Sometimes we add refried beans and/or sour cream for a more filling snack/meal
Hope that helps, be patient