I've also just read that a 2 stage DS ie VSG first, then the malabsorption bit later on, isnt as effective as a DS from the beginning!


Its only anecdotal, but i'll copy it here anyway;
'Dr. Rabkin attended the SJ DS meeting last night. We had a great wide-ranging discussion, which at one point delved into the question of whether/why 2 part DSs are less effective. Rabkin acknowledged that, while there was NO study demonstrating this, and it is unlikely that there would be (I'm assuming because how do you match patients and assign them randomly into the two different groups?), it was his impression as a bariatric surgeon that this is true.
One possible explanation:
The sleeve gastrectomy part of the DS, which by restriction provides the primary weight loss benefit, of course and by design loses effectiveness over time. This weight loss, like all calorie restriction, causes the same undesirable metabolic changes as plain old fad diets - you dial down your metabolism. which thinks you are starving, and which remains at a lower pace (higher efficiency) thereafter - thus the "yo-yo dieted myself into morbid obesity" explanation for many of us ending up fat AND with slow and damaged metabolisms from years of dieting.
When you put the sleeve TOGETHER with the switch from the git-go, the metabolic changes (better insulin sensitivity being a big part) seems to ameliorate the slowed metabolism effect of the restriction - our metabolisms DON'T slow down in response to the calorie restriction. Thus, the synergism of doing the switch and sleeve together. As we lose the weight and our sleeves stretch out, the metabolism stays up and the malabsorption, especially of fat, helps maintain our weight loss despite eating satisfying calorie-dense food.
However, 2 part sleeves don't get this benefit. Their metabolisms adapt to the initial starvation diet and become slower and more efficient. By the time the switch is added, it cannot work as well in conjunction with the caloric restriction (which by this time is much less as well, due to sleeve stretching), and while it can help the patient maintain the prior weight loss, the patient is unlikely to lose much more, unless the sleeve is resleeved (a high risk procedure) and even then, the starting point is a further damaged metabolism.
Remember - non-MO people who get the switch as a stand-alone procedure for diabetes lose about 25 lbs at first, and then regain most of it.
THIS IS THEORY, AND HYPOTHETICAL. THERE IS NO DATA TO SUPPORT IT. However, Rabkin thinks this is not inconsistent with anecdotal reports.
But this makes me even more doubtful about the sleeve as a long-term weight loss solution for most MOs with underlying metabolic issues, especially diabetes.'