How Do Unhealthy Foods Trigger Addiction and Weight Gain?

February 01, 2019 by Joel Fuhrman, MD


Calorie-dense, low-micronutrient foods can be addictive

Overweight and obesity affect two-thirds of the American population, and the abundance and accessibility of calorie-dense, low-micronutrient foods is a major contributor to this problem. Many people have difficulty stopping when consuming these foods, eating well past the point of being satiated or even physically full. However, the idea that food can be addictive is still controversial.

Research suggests salt can be addictive

Can food really be addictive?

Many scientists think so. Addiction is characterized by activation of the brain’s reward system, use of the substance or behavior despite negative consequences, loss of control, tolerance, and withdrawal. Although food addiction is not yet recognized as a psychiatric disorder, compulsive consumption of calorie-dense foods fits these characteristics.1

Research suggests the excessively sweet, salty, and/or fatty (“highly palatable”) foods common in the standard American diet can produce dysfunction in the brain’s reward system, driving loss of self-control, overeating, and weight gain.2, 3 There is evidence that the neurobiological underpinnings of compulsively eating highly palatable foods are similar to those of addiction to heroin or cocaine.4-8

 

Stimulation of dopamine receptors

In the brain: Dopamine, reward, and tolerance

Hunger is not the only reason we eat. When we eat calorie-rich foods or engage in other pleasurable behaviors, the brain’s reward system reinforces that behavior with a neurochemical called dopamine.1 The drive to consume large amounts of calorie-rich foods when they were available was advantageous for early humans, allowing them to store enough energy to survive through periods of food scarcity. But in modern times, that same drive for calorie-rich foods promotes obesity, type 2 diabetes, and other chronic diseases.

Research in animals

An early study published in Nature Neuroscience showed that rats given extended access to junk food developed binge-eating behaviors and gained weight rapidly. As this experiment continued, the rats had progressively higher “reward thresholds.”  This means that their brains’ reward systems became less and less responsive, and a greater amount of junk food was therefore required to satisfy their appetites – essentially, they developed tolerance. The scientists traced these effects to a decrease in dopamine D2 receptors in a certain region of the brain. These same neurobiological changes have been shown to occur in rats that are given extended access to heroin or cocaine.9

Sugar alone was found to produce a powerful reward response, as demonstrated by a study in which rats were allowed to choose between pressing two levers: one lever gave them access to sugar-sweetened water, and the other a dose of intravenous cocaine.  The rats preferred sugar over cocaine.10

Research in humans

Studies on brain activity have provided preliminary evidence supporting the idea that, similar to rats with access to large amounts of junk food, overeating alters the dopamine reward system in humans, which then acts to drive further overeating.

Reduced numbers of dopamine D2 receptors have been reported in obese compared to lean people, and in women with bulimia compared to healthy women. It has also been shown that the dopamine reward response is diminished over a period of weight gain or in response to frequent consumption of ice cream.1, 11-15 Another study suggested that higher-glycemic meals produced more activation in brain regions associated with reward and craving.16 Together, these studies suggest that overeating highly palatable foods results in a diminished dopamine reward response and therefore tolerance, leading to a constant cycle of addictive overeating.

Withdrawal and “toxic hunger”

In addition to the effects on the brain’s reward system, withdrawal may also contribute to overeating and food addiction. Animal studies have shown characteristic signs of withdrawal in animals, such as anxiety or teeth chattering, after access to sugar has been restricted.17-19

A diet low in micronutrients and phytochemicals and high in calories is associated with inflammation, oxidative stress, and the accumulation of toxic metabolites. 20-22 A few hours after eating, as the body begins to eliminate these waste products, uncomfortable symptoms arise, such as headaches, light-headedness, irritability, and fatigue; symptoms I refer to as “toxic hunger.” Many people recognize these symptoms as hunger, because eating ceases the detoxification process, diminishing the uncomfortable symptoms. Misinterpreting these symptoms as hunger leads people to chronically consume more calories than necessary.

High-nutrient foods are not addictive

However, the perception of hunger changes as you improve the nutritional quality your diet. Despite a lower calorie intake, headaches, lightheadedness, and other uncomfortable symptoms decline; feelings of hunger occur less frequently, are less uncomfortable, and are felt primarily in the mouth and throat: “true hunger.” These findings from more than 750 participants have been published in a peer-reviewed journal, in which 80 percent of respondents reported their perception of hunger changed.23

Health-promoting foods do not produce withdrawal symptoms or dysfunction in the brain’s reward system. The way out of food addiction is a Nutritarian diet: consuming primarily vegetables, beans, nuts, seeds, and fruit helps you resolve toxic hunger and prefer high-nutrient foods.

The avoidance of addictive foods and focus on whole plant foods also results in dramatic weight loss; in a study of 75 obese people who had switched to a Nutritarian diet, the average weight loss was 55 pounds after three years.24

In the modern world, we have around the clock access to inexpensive, low-micronutrient, high-calorie foods. This puts everyone at risk of developing addictive eating behaviors leading to obesity and its health consequences. To stay in good health, we must opt out of the standard American diet, avoid addictive foods, and focus our diets on natural, health-promoting plant foods.

 
References
  1. Taylor VH, Curtis CM, Davis C. The obesity epidemic: the role of addiction. CMAJ 2010, 182:327-328.
  2. Cocores JA, Gold MS. The Salted Food Addiction Hypothesis may explain overeating and the obesity epidemic. Med Hypotheses 2009, 73:892-899.
  3. Ifland JR, Preuss HG, Marcus MT, et al. Refined food addiction: a classic substance use disorder. Med Hypotheses 2009, 72:518-526.
  4. Gearhardt AN, Yokum S, Orr PT, et al. Neural Correlates of Food Addiction. Arch Gen Psychiatry 2011.
  5. Volkow ND, Wang GJ, Fowler JS, et al. Food and drug reward: overlapping circuits in human obesity and addiction. Curr Top Behav Neurosci 2012, 11:1-24.
  6. Avena NM, Gold JA, Kroll C, Gold MS. Further developments in the neurobiology of food and addiction: update on the state of the science. Nutrition 2012, 28:341-343.
  7. Fortuna JL. The obesity epidemic and food addiction: clinical similarities to drug dependence. J Psychoactive Drugs 2012, 44:56-63.
  8. Kenny PJ. Common cellular and molecular mechanisms in obesity and drug addiction. Nat Rev Neurosci 2011, 12:638-651.
  9. Johnson PM, Kenny PJ. Dopamine D2 receptors in addiction-like reward dysfunction and compulsive eating in obese rats. Nat Neurosci 2010, 13:635-641.
  10. Lenoir M, Serre F, Cantin L, Ahmed SH. Intense sweetness surpasses cocaine reward. PLoS One 2007, 2:e698.
  11. Stice E, Yokum S, Blum K, Bohon C. Weight gain is associated with reduced striatal response to palatable food. J Neurosci 2010, 30:13105-13109.
  12. Wang GJ, Volkow ND, Logan J, et al. Brain dopamine and obesity. Lancet 2001, 357:354-357.
  13. Volkow ND, Wang GJ, Telang F, et al. Low dopamine striatal D2 receptors are associated with prefrontal metabolism in obese subjects: possible contributing factors. Neuroimage 2008, 42:1537-1543.
  14. Bohon C, Stice E. Reward abnormalities among women with full and subthreshold bulimia nervosa: a functional magnetic resonance imaging study. Int J Eat Disord 2011, 44:585-595.
  15. Burger KS, Stice E. Frequent ice cream consumption is associated with reduced striatal response to receipt of an ice cream-based milkshake. Am J Clin Nutr 2012, 95:810-817.
  16. Lennerz BS, Alsop DC, Holsen LM, et al. Effects of dietary glycemic index on brain regions related to reward and craving in men. Am J Clin Nutr 2013.
  17. Avena NM, Bocarsly ME, Rada P, et al. After daily bingeing on a sucrose solution, food deprivation induces anxiety and accumbens dopamine/acetylcholine imbalance. Physiol Behav 2008, 94:309-315.
  18. Cottone P, Sabino V, Steardo L, Zorrilla EP. Opioid-dependent anticipatory negative contrast and binge-like eating in rats with limited access to highly preferred food. Neuropsychopharmacology 2008, 33:524-535.
  19. Colantuoni C, Rada P, McCarthy J, et al. Evidence that intermittent, excessive sugar intake causes endogenous opioid dependence. Obes Res 2002, 10:478-488.
  20. Egger G, Dixon J. Inflammatory effects of nutritional stimuli: further support for the need for a big picture approach to tackling obesity and chronic disease. Obes Rev 2010, 11:137-149.
  21. Devaraj S, Wang-Polagruto J, Polagruto J, et al. High-fat, energy-dense, fast-food-style breakfast results in an increase in oxidative stress in metabolic syndrome. Metabolism 2008, 57:867-870.
  22. Bhosale P, Serban B, Bernstein PS. Retinal carotenoids can attenuate formation of A2E in the retinal pigment epithelium. Arch Biochem Biophys 2009, 483:175-181.
  23. Fuhrman J, Sarter B, Glaser D, Acocella S. Changing perceptions of hunger on a high nutrient density diet. Nutr J 2010, 9:51.
  24. Fuhrman J, Singer M. Improved Cardiovascular Parameter With a Nutrient-Dense, Plant-Rich Diet-Style: A Patient Survey With Illustrative Cases. Am J Lifestyle Med 2015.

Joel Fuhrman, M.D. is a board-certified family physician, six-time New York Times bestselling author and internationally recognized expert on nutrition and natural healing, who specializes in preventing and reversing disease through nutritional methods. Dr. Fuhrman coined the term “Nutritarian” to describe his longevity-promoting, nutrient dense, plant-rich eating style.
 
For over 25 years, Dr. Fuhrman has shown that it is possible to achieve sustainable weight loss and reverse heart disease, diabetes and many other illnesses using smart nutrition. In his medical practice, and through his books and PBS television specials, he continues to bring this life-saving message to hundreds of thousands of people around the world.

 

Comments (0):

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Tula_Girl

02/06/2019 02:55 PM

So how do you go from eating an unhealthy diet to a nutritarian plan?  The withdrawal from sugar addiction would be unpleasant.

GeoffreyLevens replies:

02/06/2019 03:04 PM

I would say breaking sugar addiction is one of the very hardest things I"ve ever done. That was a very long time ago, at the direction of my first acupuncturist. Now at age 69  and looking at the health of my peers, I am incredibly grateful for the push and to myself for sticking it out and making it happen. The key tricks are 1) Don't cheat even a little. Even one small taste resets your brain back to full addiction mode. 2) Indulge yourself with fresh fruit! As your brain resets, fruit will start to seem like candy only ever so much better.

For overall switching to Nutritarian eating, depending on your personality, what you think would work best for you, ether start by incorporating a really huge salad every single day (that will start to crowd out some of the less nutrient dense foods) or just jump right in. Read any of Dr Fuhrman's books and follow the plan there. Simplest is 6 Week Plan outlined in Eat For Health and also posted in outline form to many blogs around the internet.

Jane0718 replies:

02/06/2019 03:14 PM

Withdrawal from unhealthy foods can be unpleasant.  I was very fortunate that I didn't experience anything that was really bad.  I would say though that heart disease, diabetes, arthritis, psoriasis, cancer (just to name a few) are much more unpleasant than withdrawals from changing to a healthy diet. I made the change over 7 years ago and my health records show it was worth it.

andywill530

02/06/2019 03:34 PM

I wholeheartedly agree about the Food Addiction in your article.  Everyday I start out real good, but by the evening when I'm relaxing I cannot seem to keep myself from munching on popcorn, chips, pumpkin seeds and other salty treats.  Then after that I want something sweet.  I go back and forth.  Sometimes I feel hopeless.  I'm on WW and it seems as if I'm wasting my money.  I really want to detox, but i'm having a terrible time trying to do it.  I have no support in my household for this.  I'm always trying to lose weight.  Just can't seem to do it.

StaceyW replies:

02/06/2019 04:17 PM

I was told that people crave salty foods when tired. I used to experience the same thing: if I ate something salty, I wanted a sweet afterward. It wasn’t until I gave up sugar and started eating fruits in place of sugar and a ton of vegetables in place of other foods (dairy, bread, and other fatty foods) that snacking on salty followed by sweet subsided. If you feel like munching, try occupying your time with something else to take your mind off the need for food. I never did well on WW because I was obsessed with food more than I ever had been! When you eat fruits, veggies, beans, and seeds with a little chicken thrown in here and there, there isn’t a need to count calories and obsess about what you’re going to eat.

Insania replies:

02/06/2019 04:18 PM

Now four months into a solid nutritarian diet, I found my way out of the same 7-11PM problem you describe.  For two decades I would start the day out just fine, all the way through lunch.  Dinner was usually huge, but within a half hour after finishing, the beginnings of another 3,500 calorie evening cram session would invariably result.  From 7 to 11, I would be absolutely uncomfortable, sick even, and when the pain subsided even a little bit I'd then cram more.  For twenty years I went to bed uncomfortable, and when I woke up I couldn't believe "I did it again...maybe today will be better."  And, it never, or rarely, was.

I found my way out recently by spending 8 weeks at the Eat to Live retreat, and it took a solid, and I do mean solid, 6 weeks to get past that initial hurdle of toxic hunger stomach growling and no salt.  It was miserable, absolutely, and particularly because the ETL retreat maintained a 15 hour intermittent fast period -- no food from 5:30PM after dinner until again at 8:30AM at breakfast.  Trying to unwind twenty years of toxic eating in just eight weeks?  I indeed saw it happen with my own eyes both with other guests and with myself.  Now two months after returning home and keeping with the same schedule, I'm finding that every day is easier to get past the desire to eat after dinner.  For me, it did not and likely will never fully go into submission, I think I will always have some level of desire to overeat, to snack, to cheat, and what-not.  I attribute much of this to low blood sugar issues I've had since I've been home (I'm a type I diabetic) but it is substantially easier to get past now and I expect it will only get better 6, 9, 12, or 18 months from now.  I fully follow a 100% nutritarian non-SOS vegan diet and I keep to regular meals with no snacks in between, so I would recommend that if you can just get started on a nutritarian diet yourself, don't give up because you would only be a few weeks from the beginnings of freedom and the removal of hopelessness.  It's simple and obviously not easy, but it's within reach.  I have also been able to do this with all my family members who all eat the standard diet, and for years I would partially blame that for my failures, but no, I recognize I have only control over myself, and so do you.  It's clearly harder with Snickers, Pop Tarts, Bagel Bites, chicken wings, pork chops, tortilla chips, sour cream and Almond Roca around...but I am doing it.  I'm proof it can be done.

Red Sox Girl

02/06/2019 03:42 PM

My big question is related to the paragraph below. When you eat a nutrient dense diet, do the number of dopamine receptors grow and/or does the dopamine response tolerance lower? In other words, are you just "doomed" as an obese person, or does the dopamine response adjust?

 

"Reduced numbers of dopamine D2 receptors have been reported in obese compared to lean people, and in women with bulimia compared to healthy women. It has also been shown that the dopamine reward response is diminished over a period of weight gain or in response to frequent consumption of ice cream.1,11-15 Another study suggested that higher-glycemic meals produced more activation in brain regions associated with reward and craving.16 Together, these studies suggest that overeating highly palatable foods results in a diminished dopamine reward response and therefore tolerance, leading to a constant cycle of addictive overeating."

This comment was last edited on 02/06/2019 03:43 PM

Dr. Ferreri replies:

02/08/2019 04:27 PM

There is not much research on this yet, however, there is evidence suggesting that the craving response to food cues is reduced by weight loss.

Bethbattaline

02/07/2019 07:48 AM

I am interested I. Finding a local doctor who subscribes to these eating practices and is more holistic. Is there a network where I can locate them in Pittsburgh- we have 2 health care systems: UPMC and High Mark- somebody has to be practicing this way - I’d prefer a possible name from this source but will look around UPMC as well (happens to be my current network). Input welcome!

onefoot7 replies:

02/12/2019 04:25 PM

I have nearly no faith in the standard medical prfession on this, they are wayyyyy off, so it is doubtful that you can find 'Correct' help....how do I know this, I am a doctor in Richmond, VA area, a foot and ankle specialist/surgeon, and I am Nutritarian, but absolutely no one else is close to this in any fields, especially Family and I Med Docs......so, I say, forget the Docs, and do it on your own with Dr. Fuhrman, that is what I do with my patients especially Diabetes patients. I have no Faith whatsoever in my colleagues on this, and even so-called 'functional Med ' practitioners have it

wayyy wrong and do NOT do Nutritarian-they can't handle it.....so, dig in and work on it on your own and use the website and Facebook.......-Dr. Lou Nordeen, [email protected]

EmmaF

02/07/2019 09:16 AM

Such a helpful blog! Grateful! These days I so wonder what Dr Furman has to say about the veganismdestroyedmyhealth trend! I have mature, sensible, sincere people tell me their issues dissappeared once they added animal products to their diet. And that they did not try as thay might find a way to thrive on a fully plant based eating style. These are all people in their thirties and fourties who exercise quite a bit, but are not athletes. And on youtube thefe is, of course, quite a lot of noise on this issue. And not all the ”ex vegans” are what Dr Garth Davis calls ”millenials with eating disorder”, far from it. A LOT of vegans are complaining of issues. One ex vegan nutritionist even has a clip of Dr Furman speaking of protein needs in older vegans in her critique of Dr Davis. I think any mature and sensible response that actually includes listening and hearing what all parties are actually saying is a good thing. But it is really hard to come across such attempts. We can always say, time will tell... but it sometimes feels just like I said, that words of reason would be helpful. Especially with vegan parents with vegan kids like myself (and ordinary vegans that I meet) becoming worried... hearing about  all the terrible deficiencies and health issues that can develop over time, according to these people... 🤔🤔🤔.

All the very best to all of you!