Serotonin Deficiency and Food Cravings

Written by: Kevin Cann

            The more I meet with people and get to know them the more I have realized that we may have another epidemic here in America that is not often addressed, serotonin deficiency.  Antidepressants are the most common medication prescribed in the United States (Olfson, 2009).  Understanding the mechanisms on how antidepressants work can help us understand what is going on in our heads.

The most commonly prescribed antidepressants are selective serotonin reuptake inhibitors (SSRI).  They are prescribed not only for depression, but also for obsessive compulsive disorders, panic disorders, and even eating disorders.  The way that these medications work is they increase the amount of serotonin at the serotonin receptor sites (Stahl, 1998).  This in the short term may make us feel better by balancing out our biochemistry.  The issue lies when our body fights back and begins to desensitize to serotonin and the medication dosage needs to be increased or medications need to be changed.

Certain foods can have a similar affect.  When we eat a food high in sugar insulin gets released to quickly take it out of the bloodstream.  Insulin removes all of the amino acids along with the sugar, except for one, tryptophan.  Tryptophan is our precursor for serotonin and it now can enter the brain without having to compete with other amino acids.  This can lead to increased amounts of serotonin in the brain (Ross, 2002).

Addiction can be linked to these neurotransmitter deficiencies.  According to Kenneth Blum’s Reward Deficiency Syndrome, we will seek out substances that balance us out biochemically.  For example, if we have low serotonin we will seek out substances that raise serotonin levels.  High sugar foods are a way for us to do this.  Blum also concluded in a study that glucose cravings are caused by a lack of dopamine receptors in the brain (Blum, 2006).

Serotonin and dopamine have a very complex relationship in the brain.  A clinical review of SSRIs showed that these drugs inhibit dopamine (Damsa, 2004).  According to this study, increased serotonin in the brain can lead to an inhibition of dopamine.  If we are eating high sugar foods or have high insulin levels, and have enough leftover tryptophan in the blood, we will have high amounts of serotonin in the brain.  If we are constantly eating high sugar foods throughout the day, perhaps our diet will mimic the SSRIs by leaving increased amounts of serotonin around the neuron for extended amounts of time, leading to less dopamine.  According to Blum’s study this will lead to more sugar cravings.  Over time of increased serotonin exposure, just like with SSRIs, we become desensitized to the neurotransmitter and mood disorders can follow.

So what can cause serotonin to become depleted?  First, let us look at diet.  High amounts of caffeine will eventually lead to serotonin issues.  Caffeine combats adenosine.  This causes a domino effect in our central nervous system.  To respond to this we release serotonin and noradrenaline.  Caffeine also increases serotonin concentration in the brainstem (Walton, 2002).  This can lead to our neurons becoming desensitized to serotonin as well as decreasing dopamine.  High sugar foods are also problematic due to the mechanisms described above.

Protein contains the amino acids that are our precursors for our neurotransmitters.  Therefore, if we aren’t eating enough protein there is not enough of these precursors to make the neurotransmitters.  Breast milk contains high amounts of tryptophan, infant formula does not.  This could leave us predisposed to becoming serotonin deficient (Ross, 2002).  B vitamins, calcium, magnesium, and vitamin D are also required to make serotonin.

Serotonin is dependent upon light.  This is where problems such as Seasonal Affective Disorder (SAD) come into play during the winter months.  On top of serotonin being stimulated by light, vitamin D is required to make it, which we also get from the light.  Chronic stress can deplete serotonin.  We release serotonin to counter the stress response.  Again, too much exposure to serotonin leads to us becoming desensitized.

So what do we do?  For one, eat a diet with ample amount of nutrients and protein.  Also, get some exercise!  Exercise works similar to insulin in that it takes all the amino acids out of the bloodstream and shovels them into muscles except for one, tryptophan.  Ever wonder why you feel better after working out?  It can be even better by exercising outside in the natural light can help stimulate serotonin.

Signs and symptoms of serotonin deficiency are low-self esteem, insomnia, phobias, panic attacks, eating disorders, depression, anger, anxiety, shy, and obsessive behaviors as well as cravings for sweets and chocolates, cravings for sweets at night, and binge eating.  If you experience a few of these symptoms chances are you are serotonin deficient and if switching up the diet to a paleo framework does not work seek the help of a qualified practitioner.




Walton, Christine (2002).  Effect of caffeine on self-sustained firing in human motor units.  The Journal of Physiology.

Damsa, C (2004).  “Dopamine-dependent” side effects of selective serotonin reuptake inhibitors: a clinical review.”  UK Pubmed Central.

Olfson, Mark (2009).  National patterns in antidepressant medication treatment.  Archives of General Psychiatry.

Stahl, Stephen (1998).  Mechanism of action of serotonin selective reuptake inhibitors: Serotonin receptors and pathways mediate therapeutic effects and side effects.  Journal of Affective Disorders.

Blum, Kenneth (2006).  Reward deficiency syndrome in obesity: a preliminary cross-sectional trial with a genotrim variant.  Advances in Therapy.

Ross, Julia (2002).  The Mood Cure.  Penguin Publishing.  London, England.



Kevin is owner of Genetic Potential Nutrition. He is a holistic nutritionist, wellness coach, and strength coach. He works with people fighting illness, to competitive athletes. Check out his site at

Categories: Anti inflammatory diet, Anxiety and Depression, General, Weight Loss


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  1. DJ says

    I had a very interesting experience after starting to eat following Mark Sisson’s Primal Blueprint diet. I’ve been on anti-depression meds for many years, but had gotten to a point where my doctor needed to continually up the dose because I was becoming increasingly depressed. At my worst I was taking 120 mg of Cymbalta (broken into morning and evening, 60 each), along with some Welbutrin, every day. As I started following the Primal Blueprint diligently, I was able to decrease the medication, first going to 60 mg. Cymbalta, plus the Welbutrin, then dropping the Welbutrin altogether, then going down to just one 30 mg. Cymbalta capsule per day. I was still feeling terrific, so I gradually tried to wean myself off of the Cymbalta altogether over the course of about a month, breaking capsules down to 15 mg. Unfortunately I fell back into a pretty significant depression after a week or so of being off of the Cymbalta completely (not sure why). I am now taking the 30 mg. per day, and am not sure it would be possible for me to completely go off of it. But this way of eating has been a huge testament to me as to how significantly our diet affects depression!!

    • says

      While eating paleo or primal is a phenomenal way to improve your health, there may still be other things that need to be addressed by a health care practitioner. Your body chemistry may be out of balance, you may be deficient is certain essential nutrients. A nutritional evaluation may help uncover the underlying CAUSE of why you seem to need that small dose of antidepressant.

  2. dennis price says

    I have been on antidepressants for 12 years. No doctor has ever suggested me to get off them nor did I ever feel better. I felt even worse this year. My energy was going down even more. I felt like a 90 yr old in a 31 yr old body. I switched to Paleo in July and I have been off antidepressants since August and I feel so much better.

  3. Jeanna says

    This article really speaks to me. In June my family and I moved across country, we have had extreme financial stress(we now live with my mother-in-law), and I stopped breast feeding. All of this has left me in a funk that I can’t seem to shake. I was doing Paleo before moving and seeing great results. I am trying so hard to have will power and start back the Paleo. Every morning I start Paleo and every afternoon I fail, miserably. I feel totally stuck! I’m thinking after reading this article that I am having some serotonin/depression issues, but where do I go to solve them? How do I know when to see the doctor? And what sort of doctor should I try to see?

  4. Scottc says

    Would be great if you could spend some time discussing the potential relationship of this article to the recent post on hypothyroid issues.

  5. Steve H says

    “High amounts of caffeine will eventually lead to serotonin issues.”

    Are there studies to support this?

    “This can lead to our neurons becoming desensitized to serotonin as well as decreasing dopamine.”

    Studies to support?

    There seems to be recent evidence in a study of women that caffeine intake can reduce the occurrences of depression.

    That said there does appear to be evidence that caffeine can cause problems if it is (1) interfering with sleep or (2) coupled with a high-stress environment.

    How much is too much?

  6. Melissa says

    I did not realize my eating could effect my mood that much. I started 10 mg of Lexapro 7 yrs ago after a difficult event in my life (not my turning 40 – lol). Helped me immensely. The next year at 41I had an aggressive form of breast cancer. After a lumpectomy, 6 months of chemo & 2 months of radiation, I had my Lexapro moved up to 20 mg a day & I started taking Wellbutrin. Again it seemed to help me immensely. However after all my cancer stuff & starting to work out again, I’d have days I’d be so physically tired that I didn’t get out of bed. I started missing work so I could just lay in bed. I didn’t want to do ANYTHING because I was just exhausted. I just thought it was only from my cancer treatments. Over the few years, I’ve had my Wellbutrin upped 2x, however I’ve never shaken the tired all the time issue. For whatever reason about 6 weeks ago at a Barnes & Noble, a book ‘Paleo for Dummies’ jumped out at me. I had never heard of it, but I was so intrigued by the little I read in the store that I bought it. I was hooked. I should also mention that during & since my cancer, my cholesterol has been high, weight has been high (I gained 50 lbs during treatments) & now I’m pre-diabetic. I also have problems with sleeping, constipation & joint pain since that time. Sometimes I felt like I was crazy because no one understood or could help me get healthy again. The Paleo lifestyle explained it all. I am now almost 100% paleo. I just have long held bad habits that are hard to stop. Sometimes I don’t even realize I’ve done it until I’ve eaten all of whatever. The last couple of weekends, my cheat meals turned into cheat weekends. I have now learned it is a horrible idea. This is the second Monday I have been in great pain. My joints hurt almost as bad as when I was doing chemo. Last Monday I was also so incredibly crabby and had such a horrible headache that I kept my office door shut so I wouldn’t yell at people. I am now determined to be 100% paleo. I cannot handle anymore Mondays like this. : )

  7. ValerieH says

    Julia Ross wrote two books about this The Diet Cure and The Mood Cure (in the above references). The solution is a diet and supplement regimen. There are assessment questionnaires in the beginning of the book. I read the Diet Cure. Sugar cravings can be short cut by taking L-Glutamine between meals. A helpful and fascinating book.

  8. Julie M says

    Excessive amounts of sugar (and alcohol) will not cause a buildup of serotonin in the brain. It is true that eating sugar/carb enables tryptophan to be brought directly to and cross the blood brain barrier. However, massive amounts of sugar will cause a greatly increased need for niacin, which when we don’t have enough from our diet (which is common) we will synthesize from tryptophan,. . . Creating a tryptophan deficiency.

    Increased sugar and alcohol usually leads to a serotonin deficiency, not an excess.

  9. Johnd419 says

    Fckin amazing things here. Im very glad to see your post. Thanks a lot and i’m looking forward to contact you. Will you kindly drop me a mail?

  10. WENDY says

    I am amazed as I have insomnia, not depression however I think they are all linked.
    For the first time I have had anxiety due to illness that went on for over a month due to viruses.
    5 HTP may be the very thing I need right now…as I have all of the deficiency symptoms.
    Thank you.

    • says

      WRONG!!! Please read my comments below. I have long warned against the use of 5HTP because it works too much like antidepressants which is very dangerous. Increasing serotonin is NOT something anyone should ever do: After spending the past 25 years writing, lecturing, doing media interviews, testifying in court cases, testifying before the FDA, the Danish Parliament, etc. on the subject of antidepressants and serotonin, I can tell you that the drug makers must absolutely love you and your spreading of THEIR misinformation about serotonin!!!!!! If you only knew what evidence is being entered into court to disprove everything you have said here! Look at just a handful of the countless deaths that have resulted from this misinformation: http://www.ssristories.NET

      You continuing to spread their serotonin lies is only going to contribute to this serotonin nightmare. Even worse it is going to drag those concerned about health into it – something the drug makers have worked hard to accomplish for a long time. Even the world’s leading expert on medical research warned in a 2010 interview with the Atlantic Monthly magazine in an article titled Lies, Damn Lies and Medical Science that 90% of research is at least tainted if not outright bogus due to influence (spelled $$$$$$$$$) by the industry!

      PLEASE work to learn the real truth about serotonin – read research BEFORE it became financially advantageous to lie to everyone about serotonin!!!

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