pre-surgery diet journal

i am watching ALOT of youtube videos of success stories online. my question is about grazing....before and/or after surgery. my nutritionist said grazing is a definite NO-NO because i will gain the weight back. i am having a hard time understanding this. why would 6 small tiny meals a day be any different than having 3 full-fledged meals (Protein, grain and fruit/veg) and then 2 to 3 Snacks during the day? i would think MY way is actually eating less because i am eating every 2-3 hours. i work from home and find that i use grazing as a means to get up and get away from my desk and to get circulation in my body. i worry that this is going to be a problem for me after the surgery. if anyone can shine some light on this for me....i would be so grateful.