Yes! My son was 5.5 months when I had surgery. Bariatric surgeon and nutritionist both said I'd have to ween him since I would not be able to breastfeed after surgery. I've always had a very average milk supply - not low but definitely not plentiful, just enough -- so I was worried. However, my son's pediatrician said even with a very restricted-calorie diet as long as I was drinking enough water the breastfeeding would not be negatively affected. And she was right!! I've been able to continue fully breastfeeding my son who is now 9 months old. Of course at 6 months we started introducing solid foods and his nursing has decreased some as a result. But he's still getting what he needs. To be sure, I rented a hospital grade baby scale before surgery. I measured exactly what my son was eating at each feed. Then a few weeks after surgery I used the scale to check in again. As long as I am hydrated, my supply stays the same. No need for me to eat extra calories, just stay fully hydrated. I also hope the nursing provides a little extra calorie burn each day so I'm reluctant to finally give it up. I cannot speak to the fat composition of the milk as I imagine that has changed now that I eat so differently. But my son is gaining weight normally. I want to share my experience because there is ALOT of misinformation out there. These surgeons are not lactation experts and frankly they're often just wrong about the impact of weight loss surgery on breastfeeding. Oh one more thing!! The anesthesiologist said once you are awake from surgery, the meds are low enough in your system that you don't actually need to pump and dump from that point forward. People still always pump and dump for 24 hours as a precaution, but if you read the studies the evidence for that need just isn't there. That said I felt like such crap in the hospital for the first 24 hours that having my son come to nurse did not seem like a good idea. Pumping wasn't fun either but you do what you must. Good luck!! Let us know how it goes!!