If you look at the diet of any creature on the planet, you'll notice one big commonality: every bite of consumed food has a purpose. Animals don't eat because they're having a craving. Rather, they seek out very specific food sources that will help them gain energy, reproduce and better respond to their environment. Consider bears, for example, which in addition to a plant-rich diet, also seek out easy proteins like insects and fish to help them store protein and fat for the long winter. You may know dogs to be primarily carnivorous (or at least high-protein omnivores), but canines also enjoy chewing on grass or raw vegetables on occasion to help enhance their digestion. Even gorillas will occasionally consume soil – yup, just some raw dirt! – to add additional minerals to their normal sugary fruit- (albeit vitamin- and fiber-rich) based meals. The cardinal rule of a natural animal diet is eating on a need-to-nourish basis.
The Non-Functional Exception
The one exception to this purpose-driven diet is…you guessed it…humans. Beyond just hunger, we eat for many different reasons, ranging from nostalgia to boredom. And nobody knows our weaknesses better than food manufacturers, who have created all kinds of food products that tap into our deepest emotional cues. Crunchy corn puffs colored with red spicy “fire” powder anyone? Or creamy ice cream studded with flecks of cookie dough? How about pickle-flavored popcorn? Are you hungry yet? Our diverse cravings are tested every time we walk into a grocery store. With such an abundance of tempting options, it's no surprise that many of us often fall victim to eating foods that are super low on the nutrient density scale – in other words – foods that are high in calories, but don't offer much in the realm of actual nutrition or benefits.