Math is an all-or-none discipline. The answer is either right or wrong. There is no gray area. No in-between. A single misstep can undermine the entire outcome. I think we can all relate to spending an hour on a problem, only to later learn that we miffed on the second step. As above, so below.
Such is the case with fat loss. While diet and exercise are so loudly espoused as the sole elements of the fat loss equation, they rarely solve the problem.