While I might agree with this in general, this paragraph needs a very big IT DEPENDS. While yeah, you can get MyFitnessPal which is useful, we cannot make such broad assumptions about all of us. First of all the idea about metabolism has been debunked (that's a great research piece for you and I can't remember which of my stories linked to the research so my apologies). Second, we need fewer calories etc, ONLY if we are not working out, not expending energy, building muscle. As an elder athlete and body builder for 47 years, I write articles about older athletes which give huge lie to this. I would check out what we now know and understand about metabolism, and I would also ask you to consider that one hell of a lot of us do not suffer the kind of sarcopenia and muscle mass loss you note here. Not only that, many of us build up as we age, and our caloric needs have to match the demand. I get your point, but I do not in any way shape or form support the wholesale assumptions about aging.