Your brain may be wired to regain lost weight

For decades, we've been told that weight loss is a matter of willpower: eat less, move more. But modern science has proven this isn't actually the case .

More on that in a moment. But first, let's go back a few hundred thousand years to examine our early human ancestors. Because we can blame a lot of the difficulty we have with weight loss today on our predecessors of the past - maybe the ultimate case of blame the parents.

For our early ancestors, body fat was a lifeline: too little could mean starvation, too much could slow you down. Over time, the human body became remarkably good at guarding its energy reserves through complex biological defenses wired into the brain. But in a world where food is everywhere and movement is optional, those same systems that once helped us survive uncertainty now make it difficult to lose weight.