Starting yoga - what to expect?

[WhoisitnowRalph]

I'm 47, pre-menopausal, 4 stone overweight, with chronic foot pain (which I need surgery for) and sacroiliac pain. I have a stressful job involving a lot of travelling, my body hurts and I get regular migraines.

Naturally I know I need to lose weight (I've been on a diet for 27 years), but I'm wondering if yoga might help improve my flexibility and ease some of the body pain while I try for the billionth time to lose a few lbs.

I tried pilates once but it wasn't a good experience, so I'm a bit shy about turning up to a class as a beginner. What should I expect, am I going to be the only fat one huffing and farting vigorously as I fail to master a basic pose?

My experience is: things where you think 'How hard can it be', eg forward bends/standing up turn out to be really tricky and take a long time to keep plugging away at, but some things where I think 'No way will I be able to do that' - it's surprising, I can actually have a stab at it (although it probably also takes ages to see sufficient improvement).

You could try body balance - a mix of yoga and pilates?