Very little in nutrition is universally accepted.

So why not do what's practically canon among modern athletes and bodybuilders - make healthy muscle development (or at least preservation) a primary goal of the diet/exercise regime. In other words, do the opposite of what all these beleaguered people are doing?

Because it generally doesn't work for weight loss. Each additional pound of muscle will burn about 3 calories per day more than that pound of fat. So if you lose 10 pounds of fat and add 10 pounds of muscle (no small feat), that will net about 30 calories per day. Less than about 5 minutes of jogging.

Adding muscle mass is great when you're already lean, which is why it makes sense for athletes and bodybuilders. But talk to NFL linemen who try to lose weight after they retire and you'll see that simply lifting weights isn't sufficient. They need to cut back on food and spend a lot of time running. And from people I know -- they'd much rather just lift weights.