Thanks for replying, bmore. That was my first thought too, but how many doctors are even aware of the benefits of fat, including saturated? Most still follow the old conventional wisdom that fat is bad, which may not be the best advice for him. If he goes low carb and low fat, I don't think that is sustainable over the long term. Apart from the lack of satiety on such a plan, what he'd mostly be eating is protein which the body can transform into sugar, burning that for energy instead of fat.

Perhaps South Beach is a good middle ground?