“Junk foods” that are sweet, salty, creamy, and/or crunchy (maybe all at once), and full of chemical goodness that spins our pleasure dials… but contain relatively few actual nutrients. This type of diet prevents leptin from doing its job of regulating our energy balance. It can even make our brains inflamed and leptin resistant. We end up feeling less satisfied. We want to eat more. And our bodies even fight to hold on to the weight we gain.

Hyper-palatability. Palatability is more than just taste — it’s our whole experience of pleasure from food. That includes taste as well as aroma, mouthfeel, texture, and the whole experience of eating. Palatability strongly influences how much we eat at meals. That seems obvious: Of course we eat more of the foods we like. And of course, some foods are more pleasurable to eat than others.

Too easy to eat

They’re what you might call “too good”. Anything that you “just can’t stop eating” would fall into this category. Reward value. Along with palatability, some foods give us a “hit” or a reward from some type of physiological effect. We’ll go out of our way to get foods with a high reward value — in fact, we may learn to like them even if they don’t taste very good. For instance, few people like black coffee or beer the first time they try them. But coffee has caffeine and beer has alcohol. Our brains like caffeine and alcohol.

So we learn quickly that coffee and beer are good things, and we learn to like (or at least tolerate) their taste. Over time we discover we like — maybe even can’t live without — them. We’ll wade through a crowded bar to buy a drink, we’ll stand in an absurdly long line for our afternoon coffee fix, and we’ll pay exorbitant amounts of money for relatively simple products. We’ll also make room for high-reward foods even when we’re full. This is why at Thanksgiving, after moaning and groaning about how full you are, you miraculously make room for pie when it’s time for dessert.