A lot of people who eat a western-type, processed diet are hesitant to transition over to a healthier nutritional regimen, in part because they believe doing so will rob them of many great pleasures and make their existence more dull. Basically, they value the powerful, but short-lasting pleasure that accompanies the consumption of highly processed foods over the more permanent benefits that can be attained from adhering to a healthy diet. This isn’t surprising, seeing as that’s arguably the way we’re hard-wired to function. It’s unfortunate though, because if only one gives healthy eating a chance, one may quickly find that junk food cravings wither or even completely disappear, and with them, much mental stress and agony.
This is something most, if not all, healthy dieters are aware of, either consciously or unconsciously; however, it’s not talked about that much. Moreover, it’s something a lot of people who cherish and are highly resistant to give up chocolate, doughnuts, pizza, and the like overlook.
The purpose of this article is not to convince or force anyone to give up highly processed foods, but rather to highlight the fact that junk food cravings are not an unavoidable part of the human psyche and that the downside of giving up highly processed foods is not as big as it may appear.
Why we like calorie-dense, sugary foods
In the natural environments in which we humans evolved, calorie-dense foods were hard to come by. Highly processed foods were obviously nowhere to be found, honey was only seasonally available in certain parts of the world, and the types of animals that one could hunt down and eat were a lot leaner than the animals that end up on the dinner plates of modern humans (1).
Given that foods rich in sugar, salt, and/or fat were quite rare in ancestral times, it’s not surprising that we have evolved an innate desire for such foods. We like sugary and fatty foods, in large part because those types of foods fueled the evolution of our kind: they provided our ancestors with energy that they could use to survive and reproduce.
The problem we have today is that calorie-dense foods are everywhere: they are no longer rare. Our primal ancestors didn’t get fat or sick if they gave into their cravings for sugar, salt, or fat; seeing as their access to those nutrients was very limited. This is important to acknowledge, as it implies that there has never been any reason for natural selection to forcefully restrain our desires for energy-dense foods, despite the fact that frequent consumption of energy-dense foods, in particular highly processed foods, has some obvious fitness costs. Among other things, it adversely affects libido, mental functioning, and immunity (2, 3, 4). Even the most experienced junk food-eater does lose his appetite after a while if he sits down and stuffs himself with chocolate and pastries; however, he can go on for quite some time before that happens.
With that said, as pointed out in the beginning, junk food cravings are not an unavoidable part of the human existence. This really goes without saying, seeing as it was only very, very recently that all off the processed, salty, and sugary foods that line the outer isles of the modern supermarket were infused into our nutritional environment.
Junk food is addictive. Here’s why…
Chocolate, doughnuts, potato chips, and other similar junk foods are supercharged versions of the most calorie-dense foods that were a part of ancestral human diets. They bear some resemblance to honey, nuts, tubers, and certain types of animal source foods; however, they are unique in that they contain extremely high concentrations of energy, sugar, salt, and fat, which are combined to make a product that taps into the most primal parts of our brains.
The consumption of junk food elicits some of the same responses in the brain as drug use does (5, 6). It gears up the production of dopamine and other hormones that cause a pleasurable feeling; a response that’s rooted in our evolutionary past.
Here’s what a 2013 review paper had to say about this matter:
This research has revealed that sugar and sweet reward can not only substitute to addictive drugs, like cocaine, but can even be more rewarding and attractive. At the neurobiological level, the neural substrates of sugar and sweet reward appear to be more robust than those of cocaine (i.e., more resistant to functional failures), possibly reflecting past selective evolutionary pressures for seeking and taking foods high in sugar and calories. (5)
Obviously, a bar of chocolate is not going to give you the same rush as crack will; however, it will without a doubt “light up” the pleasure centers of your brain. Not only that, but the consumption of junk food has a very different impact on the gut microbiota than the consumption of real, whole food (2, 4, 7, 8). The types of microbes that proliferate following the consumption of highly processed foods are capable of influencing their host in such a way that the host craves and seeks out more highly processed foods (9, 10, 11), which in turn will benefit the microbes in question, seeing as they do well on a junk food diet. The host, however, is not going to do well on such a diet. Conversely, the consumption of healthy food can help nudge the microbiota towards a state that is incompatible with a junk foods diet. You, including your microbiota, truly are what you eat.
Personally, I think this can largely explain why junk foods are so addictive, as well as why a lot of people report that they rarely or never crave junk food if they adhere to a healthy diet over time.
We’re hard-wired to like non-toxic foods that are fairly high in calories; however, we’re not doomed to go around constantly craving junk food. If you regularly crave chocolate, chips, or other similar foods, then you can be sure that there’s something “wrong” with your body. A healthy body doesn’t find junk food irresistible: it manages just fine to steer clear of the outer isles of the supermarket, at least most of the time
A lot of people are resistant to adopt a healthy diet because they are extremely fond of certain types of junk foods. They regularly crave chocolate, cookies, ice cream, and/or other highly processed foods and find the thought of giving up or severely restricting their intake of those foods almost unbearable. What many of these people fail to realise is that junk food cravings tend to become markedly less severe over time as one adopts a healthy diet. Sometimes, they almost completely disappear, and with them, the mental stress related to food choice (“I want a doughnut, but I know it’s bad for me, so I will fight my urge to eat it.”) and diet restrictions that typically accompany them. This is because the switch from a processed, unhealthy diet to a healthy diet can go a long way towards resetting areas of the brain that are involved in pleasure and reward, as well as reconfiguring the gut microbiota into a healthier state.