Why is it that some can keep lost weight at bay as long as their diet is ironclad and they don’t skip any workouts, but as soon as they slip up even a little bit, they gain weight? And when they gain, they seem to gain it faster and more easily than should be normal. It just doesn’t seem fair. What’s going on here?(This Mark's Daily Apple article was written by Mark Sisson, and is narrated by Brock Armstrong)