That's probably the problem; you're not eating enough. Talk to your bariatric nurse/dietitian, but most post op diets are around 1200/day, with Protein first, lots green veggies, Beans, etc.. If I eat less than 1100-1200, I plateau. Remember your body still needs food and energy to perform; if you're not eating enough, it will go into "starvation mode" and try to hold onto all the possible energy it can and instead use muscle in an effort to protect the vital organs. I'm guessing you're really tired as well. Talk to your physician.