How much should I be eating at a time one month post op?

Hair loss is caused by a shock to the system and is called telogen effluvium.  If it happens to you, the hair will grow back.  Eating protein will not prevent it.  

Every doctor/ nutritionist will have their set guidelines on what they feel is the recommended amount you should be taking in at each feeding. If you got a binder with info on it like i did look back in on it. I call it my weight loss bible. 

Example for me in in the Pureed Stage

7:00am- 2tbsp of Banana Mashed plus 2 TBSP. Greek yogurt 

8:30am - 8 ounces of powerade zero or something that is sugar free.

10:00am - Protein Shake

12:00pm - 2 tbsp. of pureed meat, 1tbsp. vegetable and 1 tbsp. Starch (like mashed potatoes) or fruit pureed

2:00pm- 8 ounces of powerade zero or something that is sugar free.

3:30pm - 2 tbsp ricotta cheese and 2 tbsp applesauce

4:30pm - protein shake

6:00 pm 2 tbsp. of pureed meat, 1tbsp. vegetable and 1 tbsp. Starch (like mashed potatoes) or fruit pureed

7:30 pm - 8oz broth  or 1/4 cup sugar free pudding (add some unflavored protein to either)

9:00pm - protein shake

you can experiment with cheeses. I did with laughing cow spreadable cheese and stuff. 

Good luck

The sample menus I received in my binder call for way more food than you have listed.  I will try what you've posted.  It seems much closer to what I can actually eat!