First, we
don't know what the components of a healthy diet are. We thought we did decades ago, but were blissfully unaware of micronutrients (and, as I understand it, infant formula from around this time made a bunch of babies have developmental disorders as a result). Second, we're quickly realizing that nutrition is significantly more than the sum of its parts. Nutrients taken together as opposed to separately can have significantly different effects. Calories in also doesn't necessarily equal calories absorbed.
It's a crappy analogy, but imagine this guy was trying to construct a human body out of parts. He's wired up a brain, muscles, blood vessels, nerves, a lymphatic system, and all the rest to a skeletal system. What do you think his chances of success would be?
