As humans we have this feeling of scarcity all the time. And as a dietitian, this pertains to my work in how we are always on the quest for inner nourishment which often manifests itself into soothing ourselves with food. But as the creatures we are, it is in our DNA to search for things, because at one pint in our evolution, scarcity was a very real threat and a threat to our life. We have a tendency toward a feeling of emptiness, and like animals (or your dog :) they are always on the search for food. When they find food, the gorge on it, especially on foods that would be unusual or rare, like those that are high in carbohydrates. So, one thing to know is that this is not a character flaw. This is part of how we are made and evolved. Somehow, to know that your lack of willpower is not solely responsible for overeating is helpful for many to get it under control, though counterintuitive. Basically, you need to rewire and retrain your brain against its nature.
Aside from how this relates to my line of work, it is true of other aspects of life, the "keeping up with the Joneses" parts.
Psychologist Rick Hanson, who has done tons of work illuminating how the brain works and how it relates to our sense of gratitude and happiness, suggests pausing in the ordinary moments of life and really internalizing the positive experience for a minute or two. He says if you do this a couple times a day, cumulatively, you will grow a true sense of happiness, which will lead of feeling emotionally "full", not lacking.