Just a quick comment about BMIs.

The Body Mass Index was developed by insurance companies, is generally skewed to classing lower than normal weight as 'healthy' weight and only takes into account weight vs height. It doesn't take into account things like muscle, fat percentage, bone density etc. So you can be in a normal BMI range and still be unhealthy with it, or you can be in the 'overweight' catergory and be fit as a horse.

Worrying about weight seems to be our gender's national past-time, so I understand that completely! But BMIs should not be the be-all-and-end-all of what is considered healthy, IMO.