The guys over at ASAP Science are back with more science videos, and this one tackles the problem on why some people struggle when it comes to overeating:

As explained, overeating has to do with Ghrelin, a hunger-stimulating hormone that is released and tells your brain to eat when your stomach is empty. When you're full, your body releases another hormone called Leptin, which kills your appetite. But high energy (fatty, sugary, carb-loaded) foods that used to be scarce has become so readily available, overwhelming our body's natural hungry/full response.  It's not a perfect theory, and ASAP Science cites some of the studies that supports it.

So how do we overcome overeating. If willpower is limited, you can fight back by limiting your junk food intake to reboot your diet. Because if you surround yourself only with the good stuff, you'll eventually only prefer to eat the good stuff. Stick to your plan and you'll be on your way to building a new, healthy you.