[XorNot]

People screw it up by trying to measure energy expenditure is the problem I consistently see.

There is never a reason to do this: people do it because they want to eat more, so they want to factor exercise in.

They're basically already sabotaging the process from the outset: the goal is generally weightloss, they have an easy and precise way to track that, and one week of "under eating" isn't going to kill anyone.