I agree in principle with some elective procedures being postponed to ensure the best outcome for the patient.
Certainly obesity is one area where there are worse outcomes (depending on the type of surgery) but my understanding is that this relates to patients with a BMI in the morbidly obese category. From discussing with the orthopaedic surgeons here, there is no evidence to show worse outcomes following joint replacement surgery in those patients who have a BMI of 25-35 compared with those patients who have a BMI under 25.
There is, however, pretty good evidence to suggest that obesity has no effect on outcomes following major cancer surgery, but that those who were underweight had 5 times the mortality. Article here
This is quite a nice meta-analysis demonstrating no effect on ICU outcomes for obese patients but possibly a lower hospital mortality.
And this one shows no association between higher BMI and outcomes.
Orthopaedic study showing that obesity is linked to longer operation times, but has no significant influence on perioperative morbidity.
Patients with a BMI of 25-30 are no more challenging, anaesthetically, than those with a BMI of 20-25. 30-35 can be more interesting but generally aren't. Once you get over 35 then things can be technically more difficult in terms of siting lines and breathing tubes, or putting in regional blocks. There's a higher failure rate for regional blocks if you're obese, making it more likely that you'll have to have a general anaesthetic.
Why I don't like this particular decision is that it's dressed up as outcome-driven when in reality it's probably cost driven. I don't see why waiting a year for elective surgery if your BMI is 32 is going to make any difference to your outcome, except for the fact that your pain is going to be the same or worse for the year, your mobility is going to be less for the year and your ability to work is going to be severely impacted. I don't think it's going to act as the carrot to make people lose weight because if it were that simple we wouldn't have an obesity problem.
I am also concerned about which operations are being delayed. Elective joint replacement is one thing, but there are other elective procedures which can present as emergencies if left untreated (hernias being a case in point) - and if it's too risky to operate electively, the risk isn't going to go down when they pitch up in ED needing an emergency repair.