Many people who’ve long been accustomed to a westernized, highly processed diet are hesitant to adopt a real-food diet, in part because they anticipate lower hedonic value in such food (in taste, texture, and mouthfeel). Essentially they prioritize the powerful, but short-lived, pleasure they derive from consuming highly processed foods over the more permanent benefits they would accrue from a healthy diet. This isn’t surprising, given that we’re hard-wired to function this way; yet if we give healthy eating a chance, we often find that junk food cravings wither or even completely disappear, and with them much mental stress and agony.
Most health-seekers are aware of the above phenomenon, either consciously or unconsciously; however, the processed-food crowd may have trouble imagining such a transformation.
The purpose of this article is not to persuade anyone to give up highly processed foods, but rather to demonstrate that junk-food cravings are not an unavoidable part of the human experience—and that the cost of ditching such foods is smaller than it may appear.
Why We Like Calorically Dense, Sugary Foods
In the wild environments in which we humans evolved, calorically dense foods were difficult to obtain. Highly processed foods were nowhere to be found, honey was only seasonally available in certain parts of the world, and game animals were a lot leaner than the livestock we raise for our animal protein today.
Given that foods rich in sugar, salt, and/or fat (rare during our hunter-gatherer days) provided us with precious sources of potent energy, it’s not surprising that we evolved an innate desire and preference for such foods. We love sugary and fatty foods because they helped fuel the evolution of our species, giving us the vigor to hunt, evade predators, migrate, and reproduce in tough environments—as well as to grow bigger, more powerful brains than our primate cousins.
Our problem is that, today, calorically dense foods are ubiquitous. Our primal ancestors didn’t get fat or sick if they gave in to their cravings for sugar, salt, or fat, since their access to those nutrients was very limited. Therefore, there has never been any reason for natural selection to curb our desire for energy-dense foods, despite the fact that their frequent consumption (in the case of highly processed items) exerts some obvious fitness costs. Among other effects, it adversely affects libido, mental functioning, and immunity.
Yet once again, junk-food cravings are not an inevitable challenge of human life. Indeed, only very recently were most processed, salty, and sugary foods available in the modern supermarket even developed.
We’re hardwired to like natural, 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 similar foods, you might want to investigate further. Perhaps it’s chronic stress, hormonal imbalance, nutrient deficiencies . . . or else habituation to these foods’ overstimulating flavors, in which case a period of avoidance might lessen their call. Here’s why:
Why Junk Food is Addictive
Chocolate, doughnuts, potato chips, and other similar junk foods are hyper-palatable versions of the most calorically dense foods that featured in 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 combine extremely high concentrations of sugar, salt, and fat in specific ratios designed (by corporations) to overstimulate the most primal parts of our brains.
The consumption of junk food, studies suggest, elicits similar responses in the brain as drug use. It elevates the production of dopamine and other hormones that cause pleasurable feelings, a response that’s rooted in our evolutionary past.
A 2013 review paper posited that “sugar and sweet reward can not only substitute to addictive drugs, like cocaine, but can even be more rewarding and attractive…possibly reflecting past selective evolutionary pressures for seeking and taking foods high in sugar and calories.” More recent research highlights the effect of intermittent access to sweets on these results, but heightened neurochemical response is still an important factor to consider in food choice.
Obviously, a bar of chocolate is not going to give you the same rush that cocaine 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 from that of the consumption of real, whole food. 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.
The types of microbes that proliferate following the consumption of highly processed foods are capable of inducing cravings for more of such foods in their host, in order to satisfy their own preferences for certain nutrient substrates. The host, however, is not going to do well on such a diet. Conversely, the consumption of healthy food can help nudge the microbial community towards a species composition that is incompatible with a junk foods diet.
You, including your microbiota, truly are what you eat.
A lot of people are resistant to adopting an unprocessed, real-food diet because they are extremely fond of certain types of processed foods. They regularly crave chocolate, cookies, ice cream, and/or other highly processed foods and find the thought of ceasing or restricting their intake of those foods almost unbearable. What they may not realize is that junk-food cravings tend to become markedly less severe over time as one adopts a healthy diet. Sometimes, they disappear almost completely, along with mental stress around food choice (“I want doughnuts, but they’re unhealthy, so I’ll avoid them”) and the dietary restrictions that typically accompany them. This is because the switch from a processed, nutrient-poor diet to a nutrient-dense diet can help re-calibrate the pleasure-and-reward mechanisms at work in the brain, as well as reconfigure the gut microbiota into a healthier state.
1 Wolf, Robb. Wired to Eat: Turn Off Cravings, Rewire Your Appetite for Weight Loss, and Determine the Foods That Work for You. New York: 1st ed., Harmony, 2017.
2 Ahmed SH, Guillem K, Vandaele Y. “Sugar Addiction: Pushing the Drug-Sugar Analogy to the Limit.” Curr Opin Clin Nutr Metab Care 16.4 (Jul 2013): 434-9.
3 Alcock J, Maley CC, Aktipis CA. “Is Eating Behavior Manipulated by the Gastrointestinal Microbiota? Evolutionary Pressures and Potential Mechanisms.” Bioessays 36.10 (Oct 2014): 940-9.
4 Alonso-Alonso M, Woods SC, Pelchat M, Grigson PS, Stice E, Farooqi S, Khoo CS, Mattes RD, Beauchamp GK. “Food Reward System: Current Perspectives and Future Research Needs.” Nutr Rev 73.5 (May 2015): 296-307.
5 Campbell AW. “Autoimmunity and the Gut.” Autoimmune Dis 2014 (2014): 152428.
6 David LA, Maurice CF, Carmody RN, Gootenberg DB, Button JE, Wolfe BE, Ling AV, Sloan Devlin AS, Varma Y, Fischbach MA, Biddinger SB, Dutton RJ, Turnbaugh PJ. “Diet Rapidly and Reproducibly Alters the Human Gut Microbiome.” Nature 505.7484 (23 Jan 2014): 559-63.
7 Davidson B, Maciver J, Lessard E, Connors K. “Meat Lipid Profiles: A Comparison of Meat from Domesticated and Wild Southern African Animals.” In Vivo 25.2 (Mar-Apr 2011): 197-202.
8 Desai MS, Seekatz AM, Koropatkin NM, Kamada N, Hickey CA, Wolter M, Pudlo NA, Kitamoto S, Terrapon N, Muller A, Young VB, Henrissat B, Wilmes P, Stappenbeck TS, Nunez G, Martens EC. “A Dietary Fiber-Deprived Gut Microbiota Degrades the Colonic Mucus Barrier and Enhances Pathogen Susceptibility.” Cell 167.5 (17 Nov 2016): 1339-53.e21.
9 Fetissov SO. “Role of the Gut Microbiota in Host Appetite Control: Bacterial Growth to Animal Feeding Behaviour.” Nat Rev Endocrinol 13.1 (Jan 2017): 11-25.
10 Gómez-Pinilla F. “Brain Foods: The Effects of Nutrients on Brain Function.” Nat Rev Neurosci 9.7 (Jul 2008): 568-78.
11 Myles IA. “Fast Food Fever: Reviewing the Impacts of the Western Diet on Immunity.” Nutr J 13 (17 Jun 2014): 61.
12 Norris V, Molina F, Gewirtz AT. “Hypothesis: Bacteria Control Host Appetites.” J Bacteriol 195 (2013): 411-6.
13 Voreades N, Kozil A, Weir TL. “Diet and the Development of the Human Intestinal Microbiome.” Front Microbiol 5 (22 Sep 2014): 494.