Think of a scalar potential shaped like a cirque. A body in the depression can be perturbed a little without falling out, because it meets a restoring force at the walls. But if the body is moving fast or the wall of the depression becomes flat, then the body moves out and falls down the mountain side. A lot of energy is then required to move it back up. Shminux is just saying that people dieting are in a local minimum of their potential, and it doesn’t take much motivational impetus to make them fall off the wagon. Not a perfect analogy, but it’s understandable.
Think of a scalar potential shaped like a cirque. A body in the depression can be perturbed a little without falling out, because it meets a restoring force at the walls. But if the body is moving fast or the wall of the depression becomes flat, then the body moves out and falls down the mountain side. A lot of energy is then required to move it back up. Shminux is just saying that people dieting are in a local minimum of their potential, and it doesn’t take much motivational impetus to make them fall off the wagon. Not a perfect analogy, but it’s understandable.