I think it really depends on the surgeon. I went with one of the top bariatric surgeons in Australia, hes the one who first started using a minimally invasive method to do the surgery in Australia and trained other surgeons to do it that way.
My surgeon and dietitian said its highly recommended to stay on the fluids for three weeks unless you cant tolerate the shakes. The only shake flavour ive been able to tolerate since surgery is the coffee one, the other flavours made be very nauseous, and even then having more than one of the coffee shakes per day made me nauseous. Ive mostly been living on fluids the three weeks, except for the cottage cheese every couple days. According to studies, its safe from a surgical perspective to start on puree at 5 days post op, but you dont have to if you dont want to, you can simply stay on the fluids for the three weeks.
My surgery came with a complete package of the surgeon, registered nurse, dietition/nurtitionist, counselling and the fresh start program so i trust my highly experienced team who im in regular contact with. I didnt spend two years researching surgeons to just go with someone who doesnt know what theyre doing, i went with my surgeon for a reason, that hes one of the best in Australia. Im also a registered nurse so i really knew what to look out for when finding the perfect surgeon for me.
Ive known some people who do 2 weeks fluids, 2 weeks puree, 2 weeks soft and then normal diet. Some ive known do only a couple days of fluids then by day 3 or 4 theyre on puree and then 2 weeks post op on a soft diet. So it really depends on the surgeon your with and who actually keeps up to date with the current research. Personally i wouldnt have gone with a surgeon who said puree at 3 days post op then soft at 2 weeks!