Is Your Brain Hardwired for Junk Food?

Junk Food | The Paleo Diet

While the title of this article may at first seem implausible (and somewhat scary), a new scientific study seems to show that an inborn preference for junk food is not only possible – it may be affecting more of us than ever could have possibly been imagined. For the first time in history, researchers for Obesity Society have identified two genetic variants, which help to change how the brain responds to high-calorie foods.1 2 While this is potentially terrible news for those of us who struggle to resist highly processed and manufactured foods – it also means there is possibly a way to stop this genetic variant from controlling our dietary choices. This could include changing how the brain processes junk food, changing how much people crave these foods, and even altering the brain’s dopamine system. There are even more potential treatments using this new information – including using gut hormones to act on dopamine brain cells.

To delve into further detail, researchers specifically found that two genetic variants – FTO and DRD2 – influenced brain activity related to the reward system. This occurred when subjects simply looked at pictures of high-calorie foods. As I’ve written previously, this is far from the first time neuroscience (or other scientific studies) have shown that some of our brains respond differently, to rewarding foods.3 4 5 6 7 8 9 10 11 In early 2014, for example, a study was published which showed that not only did some people crave chocolate (while others did not) – but that there was literally different brain activity, in the two groups.12

Asmaro D, Liotti M. High-caloric and chocolate stimuli processing in healthy humans: an integration of functional imaging and electrophysiological findings. Nutrients. 2014;6(1):319-41.

In another, similar study, researchers found that by altering dopamine receptors (specifically D2 receptors) – they could cure binge eating.13 Unfortunately for us, that ground breaking study was done on rats – not humans. However, this is further evidence that our brain plays a fundamental role in overeating and cravings. In fact, it may be the excess stimulation of the nucleus accumbens (the ‘pleasure center’ of the brain) from junk food, which leads to obesity.14 15 16 17 18 19 20

How does this relate to our current world? Well, 70% of the United States is overweight, with 30% of us now being obese.21 What accounts for all these extra pounds? Certainly, as shown by research from Yale scientists, a hyper-stimulatory environment and excess advertisement of junk food – is a large part of the problem.22 23 24 But this data is compounded by other research, which shows that extended access to high-fat and high-sugar food, results in behavioral and physiological changes – which are similar to those caused by illegal drugs.25 [26] While a large portion of these corresponding studies were conducted on rats, this does not mean that the results will not translate to humans. Like many areas of scientific research, we simply need more data.

Baik JH. Dopamine signaling in food addiction: role of dopamine D2 receptors. BMB Rep. 2013;46(11):519-26.

As I’ve covered previously, the neurobiology of sugar addiction is fascinating as well.27 28 The brain is bombarded with an overwhelming amount of chemicals and reward, when you consume junk food.29 30 31 32 Over time, this leads to a higher quantity of junk food needing to be consumed, to achieve the same rewarding effect.33 34 35 So even for those of us who are not genetically susceptible to the temptations of junk food, we can alter our brain’s preferences and reward receptors, to become just as likely to crave it.36 37 38 39 40

Gómez-pinilla F. Brain foods: the effects of nutrients on brain function. Nat Rev Neurosci. 2008;9(7):568-78.

The good side of all this bad news? Your brain can also be positively impacted by food.41 42 43 44 45 46 A Paleo diet, which is full of nutrient dense foods, will help keep you satiated, and keep your brain from craving high sugar, nutritionally empty choices. Be sure to load your plate with wild-caught fish (high in brain-friendly omega-3 fatty acids), healthy fats (like avocados) and complete sources of protein (like grass fed beef). You may indeed be hardwired for junk food – but that doesn’t mean you have to give in to temptation. Adopting a Paleo diet is associated with many different health benefits – many of which work to counteract the negative effects of junk food.47 48 49 50 What this means, is that you can improve your health drastically, by simply changing what’s on your plate. Start eating a Paleo diet today, and watch your health soar!


1. Available at: Accessed November 23, 2015.

2. Available at: Accessed November 23, 2015.

3. Fortuna JL. The obesity epidemic and food addiction: clinical similarities to drug dependence. J Psychoactive Drugs. 2012;44(1):56-63.

4. Garber AK, Lustig RH. Is fast food addictive?. Curr Drug Abuse Rev. 2011;4(3):146-62.

5. Grimm O., Jacob M.J., Kroemer N.B., Krebs L., Vollstädt-Klein S., Kobiella A., Wolfensteller U., Smolka M.L. The personality trait self-directedness predicts the amygdala’s reaction to appetizing cues in fMRI. Appetite. 2012;58:1023–1029.

6. Macht M., Mueller J. Immediate effects of chocolate on experimentally induced mood states. Appetite.2007;49:667–674.

7. Kringelbach M.L. The human orbitofrontal cortex: Linking reward to hedonic experience. Nat. Rev. Neurosci. 2005;6:691–702.

8. Francis S.T., Head K., Morris P.G., Macdonald I.A. The effect of flavanol-rich cocoa on the fMRI response to a cognitive task in healthy young people. J. Cardiovasc. Pharm. 2006;47:S215–S220.

9. Small D.M., Zatorre R.J., Dagher A., Evans A.C., Jones-Gotman M. Changes in brain activity related to eating chocolate: From pleasure to aversion. Brain. 2001;124:1720–1733.

10. Kemmotsu N., Murphy C. Restrained eaters show altered brain response to food odor. Physiol. Behav.2006;87:323–329.

11.  Blechert J., Feige B., Hajcak G., Tuschen-Caffier B. To eat or not to eat? Availability of food modulates the electrocortical response to food pictures in restrained eaters. Appetite. 2010;54:262–268.

12. Asmaro D, Liotti M. High-caloric and chocolate stimuli processing in healthy humans: an integration of functional imaging and electrophysiological findings. Nutrients. 2014;6(1):319-41.

13. Halpern CH, Tekriwal A, Santollo J, et al. Amelioration of binge eating by nucleus accumbens shell deep brain stimulation in mice involves D2 receptor modulation. J Neurosci. 2013;33(17):7122-9.

14. Lawrence NS, Hinton EC, Parkinson JA, Lawrence AD. Nucleus accumbens response to food cues predicts subsequent snack consumption in women and increased body mass index in those with reduced self-control. Neuroimage. 2012;63(1):415-22.

15. Salamone JD, Cousins MS, Mccullough LD, Carriero DL, Berkowitz RJ. Nucleus accumbens dopamine release increases during instrumental lever pressing for food but not free food consumption. Pharmacol Biochem Behav. 1994;49(1):25-31.

16. Olausson P, Jentsch JD, Tronson N, Neve RL, Nestler EJ, Taylor JR. DeltaFosB in the nucleus accumbens regulates food-reinforced instrumental behavior and motivation. J Neurosci. 2006;26(36):9196-204.

17. Day JJ, Carelli RM. The nucleus accumbens and Pavlovian reward learning. Neuroscientist. 2007;13(2):148-59.

18. Pratt WE, Kelley AE. Nucleus accumbens acetylcholine regulates appetitive learning and motivation for food via activation of muscarinic receptors. Behav Neurosci. 2004;118(4):730-9.

19. Salamone JD, Correa M, Mingote S, Weber SM. Nucleus accumbens dopamine and the regulation of effort in food-seeking behavior: implications for studies of natural motivation, psychiatry, and drug abuse. J Pharmacol Exp Ther. 2003;305(1):1-8.

20. Demos KE, Heatherton TF, Kelley WM. Individual differences in nucleus accumbens activity to food and sexual images predict weight gain and sexual behavior. J Neurosci. 2012;32(16):5549-52.

21. Available at: Accessed November 23, 2015.

22. Yokum S, Gearhardt AN, Harris JL, Brownell KD, Stice E. Individual differences in striatum activity to food commercials predict weight gain in adolescents. Obesity (Silver Spring). 2014;22(12):2544-51.

23. Udo T, Weinberger AH, Grilo CM, et al. Heightened vagal activity during high-calorie food presentation in obese compared with non-obese individuals–results of a pilot study. Obes Res Clin Pract. 2014;8(3):e201-98.

24. Gearhardt AN, Roberto CA, Seamans MJ, Corbin WR, Brownell KD. Preliminary validation of the Yale Food Addiction Scale for children. Eat Behav. 2013;14(4):508-12.

25. Epstein DH, Shaham Y. Cheesecake-eating rats and the question of food addiction. Nat Neurosci. 2010;13(5):529-31.

26. Stockburger J., Schmälzle R., Flaisch T., Bublatzky F., Schupp H.T. The impact of hunger on food cue processing: An event-related brain potential study. Neuroimage. 2009;47:1819–1829.

27. Yang Q. Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings: Neuroscience 2010. Yale J Biol Med. 2010;83(2):101-8.

28. García-cáceres C, Tschöp MH. The emerging neurobiology of calorie addiction. Elife. 2014;3:e01928.

29. Norton P, Falciglia G, Gist D. Physiologic control of food intake by neural and chemical mechanisms. J Am Diet Assoc. 1993;93(4):450-4.

30. Wurtman RJ. Nutrients affecting brain composition and behavior. Integr Psychiatry. 1987;5(4):226-38.

31. Young SN. How to increase serotonin in the human brain without drugs. J Psychiatry Neurosci. 2007;32(6):394-9.

32. Wang GJ, Volkow ND, Telang F, et al. Exposure to appetitive food stimuli markedly activates the human brain. Neuroimage. 2004;21(4):1790-7.

33. Baik JH. Dopamine signaling in food addiction: role of dopamine D2 receptors. BMB Rep. 2013;46(11):519-26.

34. Lietti C.V., Murray M.M., Hudry J., le Coutre J., Toepel U. The role of energetic value in dynamic brain response adaptation during repeated food image viewing. Appetite. 2012;58:11–18.

35. Meule A. Are certain foods addictive?. Front Psychiatry. 2014;5:38.

36. Davis C, Curtis C, Levitan RD, Carter JC, Kaplan AS, Kennedy JL. Evidence that ‘food addiction’ is a valid phenotype of obesity. Appetite. 2011;57(3):711-7.

37. Reward systems and food intake: role of opioids. International Journal of Obesity. 2009;:S54.

38. Naleid AM, Grace MK, Chimukangara M, Billington CJ, Levine AS. Paraventricular opioids alter intake of high-fat but not high-sucrose diet depending on diet preference in a binge model of feeding. Am J Physiol Regul Integr Comp Physiol. 2007;293(1):R99-105.

39. Woolley JD, Lee BS, Fields HL. Nucleus accumbens opioids regulate flavor-based preferences in food consumption. Neuroscience. 2006;143(1):309-17.

40. Zhang M, Gosnell BA, Kelley AE. Intake of high-fat food is selectively enhanced by mu opioid receptor stimulation within the nucleus accumbens. J Pharmacol Exp Ther. 1998;285(2):908-14.

41. Gómez-pinilla F. Brain foods: the effects of nutrients on brain function. Nat Rev Neurosci. 2008;9(7):568-78.

42. Bourre JM. Effects of nutrients (in food) on the structure and function of the nervous system: update on dietary requirements for brain. Part 1: micronutrients. J Nutr Health Aging. 2006;10(5):377-85.

43. Hill JO, Berridge K, Avena NM, et al. Neurocognition: the food–brain connection. Adv Nutr. 2014;5(5):544-6.

44. Armelagos GJ. Brain evolution, the determinates of food choice, and the omnivore’s dilemma. Crit Rev Food Sci Nutr. 2014;54(10):1330-41.

45. Galland L. The gut microbiome and the brain. J Med Food. 2014;17(12):1261-72.

46. Lachance L, Ramsey D. Food, mood, and brain health: implications for the modern clinician. Mo Med. 2015;112(2):111-5.

47. Kowalski LM, Bujko J. Evaluation of biological and clinical potential of paleolithic diet.. Rocz Panstw Zakl Hig. 2012;63(1):9-15.

48. Konner M, Eaton SB. Paleolithic nutrition: twenty-five years later. Nutr Clin Pract. 2010;25(6):594-602.

49. Klonoff DC. The beneficial effects of a Paleolithic diet on type 2 diabetes and other risk factors for cardiovascular disease. J Diabetes Sci Technol. 2009;3(6):1229-32.

50. Frassetto LA, Schloetter M, Mietus-synder M, Morris RC, Sebastian A. Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. Eur J Clin Nutr. 2009;63(8):947-55.

Comments to this website are moderated by our editorial board. For approval, comments need to be relevant to the article and free of profanities and personal attacks. We encourage cordial debates for the betterment of understanding and discovery. Comments that advertise or promote a business will also not be approved, however, links to relevant blog posts that follow the aforementioned criteria will be allowed. Thank you.

“1” Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

Affiliates and Credentials