Just be patient. It is impossible to eat as few calories as we eat post surgery and not lost weight. Your body is just adjusting. I have learned from many others on this site that happens to most of us within the first month and is often around week three and called the three week stall for that reason. If you do a search for the term you will see how common it is. Stick to your plan and you will be losing before you know it.
5 weeks post surgery and your story was mine to a T on the liquid phase. I ended up having a few mouthfuls of shake then waited until I was hungry again and repeat. My dietician was more interested in me keeping up protien and fluids than me not eating between meals.
I also found adding an extra 150mls of Water to the shakes to thin their consistency helpful. Once you get on solid food this problem goes away. Hang in there. It gets better and the journey is different for all of us.
If in doubt always check in with your dietician. They really are the experts and have lots of good advice. I wish you well x
