Caring for a Three Legged Dog or Cat

We have basically did our own "diet" since Carly was diagnosed. When we got her blood work done after chemo, with Carly's weight at 60 kg. (132 pounds), they would like her on a 1,600 calorie diet. Now, before she went into surgery, she was 156. So she has lost about 6 pounds with the leg, and the rest has been weight loss. What we are running into is, with the food we have switched her too, Whole Earth Farms Chicken and Turkey Grain Free, she gets one cup of that (348 calories), one cup of chicken breast (231 calories), one cup of brown rice (320 calories) or broccoli and one cup of cottage cheese (210 calories) or a couple tablespoons of yogurt, she is getting about 1100 calories IN ONE MEAL! And we have noticed, the last 3 or 4 days, she has been acting like she is starving, eating her food faster, and starting to beg again.  So basically we are going to have to cut that one meal in half. So we want her to be able to move around easier and lessen the pressure on her other joints, although she is having no problems getting around now, she does tend to tire easy. They also suggested feeding her smaller meals more often, so we have added lunch in, and hope that helps with the hunger, but will probably exceed the calories. Anyone else have any suggestions or dealt with this kind of calorie restriction with their Tripawd with Osteosarcoma?