Here's an interesting (although simplified) tidbit, spawned by my reading a thread on MH about losing fat. There's a guy over there who wants to lose fat (like 75% of the people over at MH). One suggestion that I have seen for people looking to lose that last 6%, or whatever, is to "bulk". The theory is that if you gain muscle, then you will burn more calories at rest (i.e. while doing nothing). This really makes no sense to me, since, in order to increase body mass, an excess of calories has to be consumed; and the increase in muscle mass as a result of this "bulk" likely has a negligible effect on "fat loss".
If we use the generalized Minnesota BMR formulae, an increase of 5 pounds in body weight (I'm not sure what % body fat the Minnesota formulae use) results in an increased BMR of approximately 30-35 calories per day. That's it. That's even after accounting for activities (because the cost of activities doesn't necessarily go up exponentially with a linear increase in mass).
There are lots of benefits to lifting weights. You get stronger, you _do_ improve muscle tone (as differentiated from "toning"), you may be less prone to some injuries (though you expose yourself to a whole new set of them when you lift weights), there's evidence to suggest weight lifting may help improve bone and tendon health. BUT, is one of the benefits to lifting weights REALLY "weight loss" (apart from the increased caloric expenditure that wouldn't be there if you did nothing instead of lifting weights)? Or is the claim that weight lifting (or perhaps we should call it "increasing lean body mass" and throw the two--eating and lifting--in the pool together) is an "easier" way to weight loss simply a claim that is geared toward the population of people that want their proverbial cake to have and to eat?