IF is voluntary and can be a life changing restructuring of your food relationship.
Depending on the bariatric surgery option, you pretty much involuntarily have to change your food relationship, as with some options sugars make you physically ill.
If you have any chance to change your lifestyle without surgery, you owe it to yourself to try.
Low metabolism is a bull term anyways. Did he actually measure your metabolism? The difference in metabolism between people varies for multiple reasons. Really big people often have higher to move all the blood and the feeding of all the tissues. Fixing your issues will rely on more than a dangerous surgery. I would recommend a second opinion or three is you can. I personally would never recommend the surgery to someone that was not fully educated on the negative side effects. I have worked with quite a few of my own patients with it (physiotherapist) and i have personally not been super impressed with the outcomes. I find the headspace around food continues to be problematic.
I question your doctor. I maintained a bmi of between 18 and 20 for the better part of the past 18 years by calorie counting. I’ve had two spikes. I beat one, and now i’m trying to beat the other. Also so what if you have a low metabolism? Is food the lord of your life?
I had a very aggressive procedure called duodenal switch. I lost 175 pounds, but of course, you can out eat any bariatric procedure. I put on 30 pounds of COVID weight, and used IF to get it off in about 30 days.
I had been battling obesity my entire life. I would lose, and then regain. Even when I was losing, without the surgery, I never made it out of the obese category to a so-called normal weight.
Sometimes it takes more than an single tool to complete the job. 😊