Can Nutrition Change Your Personality?

Research suggests it’s possible to reduce anger, anxiety, addictive behaviors, and much more—with foods and supplements.
Research suggests it’s possible to reduce anger, anxiety, addictive behaviors, and much more—with foods and supplements

We’ve all heard the expression “You are what you eat.” But if emerging research is any indication, it might be more accurate to say, “Who we are is what we eat.” It turns out, what we take in—whether food, liquid, or supplement—is a factor in both our moment-to-moment moods and even our long-term self-perceptions and relationships with others. It can encourage (or prevent) the playing-out of inherited predispositions such as motivation, outgoingness, over-sensitivity, and compulsiveness. Because nutrition dominates neurological and hormonal influences on the brain, it can affect countless behavior patterns that most view as character-driven.

Is Your Real Personality Under Siege?

Life is full of emotional responses to real circumstances. But if feelings or behaviors such as low moods or negative reactions to stress become increasingly common, prolonged, or magnified, there may be more at play. Over time, poor nutrition can cause emotional and physical changes that can come to define your personality and even your success in life.

I remember living under a constant black cloud of debilitating mood swings that started in my teens, soon after I began restricting calories in response to weight gain at puberty. This led to my first binge, and what I thought was purely “emotional eating.” But no matter how much progress I made with my “emotional triggers,” my desire to binge overpowered my willpower each day for the next 12 years—until my liver began to fail. The reason I’m alive today and have been completely free of this unhealthy cycle of behavior for 25 years is not because I finally mustered eternal willpower and completely conquered my past “issues” (and there were many). It was conquering my biochemistry by changing my diet that restored my inner peace after all else failed. I now teach clients the nutrition protocol that helped me get my life back.

You needn’t have an addiction like mine to experience freedom from countless other forms of mood and behavior “imposters” posing as who you are. These imposters may include feeling more chronically stressed, distracted, obsessed, or bored than in the past, or thoughts that are more focused on food, drink, drugs, shopping, or gambling for a “lift” or to relax or sleep. Could preventing unwelcome behaviors be as simple as changing your diet and taking strategic supplements?

Nutrition and Neurochemicals

Every mood—even if it’s in response to a real situation— is moderated by neurotransmitters including epinephrine, norepinephrine, serotonin, and dopamine. All are profoundly influenced by nutrition.

In the 1980s, neuroscientist Kenneth Blum and his research team identified what they called reward deficiency syndrome (RDS). In RDS, low levels of “pleasure” neurotransmitters like dopamine drive compulsive behaviors, depression, anxiety, sleeplessness, and antisocial, addictive, and even criminal behaviors—and can influence food, drink, and other choices. RDS is genetically influenced, but Blum’s studies found that nutrition is also a factor. Blum identified amino acids, B vitamins, and other nutrients that help restore “short circuits” in brain function, often normalizing mood and cognitive issues, and relieving the drive to use sugar, alcohol, caffeine, painkillers, or other Band-aid fixes. It was a stroke of luck 25 years ago when I picked up the amino acid L-tyrosine to help my thyroid, and some probiotics and fish oil for my eczema (not knowing they would also help heal my own RDS and transform my moods).

Sugar and Mood

Sugar is everywhere. It’s a legal drug that can create lifelong addicts out of healthy children and cause a myriad of behavioral issues (not to mention equally distressing health decline). Reactive hypoglycemia refers to the classic “sugar crash” (low blood sugar that occurs after a “sugar high”). This reaction has been correlated with low serotonin (a key neurotransmitter linked to well-being), and shown to bring on symptoms including depression, anxiety, irritability, confusion, and exhaustion. On the more serious end of the spectrum, hypoglycemia has been linked to phobias, self-isolation, suicidal thoughts, rage, and violence. An infamously brutal tribe in Peru was found to have extremely high rates of hypoglycemia.

Alcohol can have the same effect. Low blood sugar following alcohol consumption has been correlated with violent crimes. Virtually all addicts, including many alcoholics, are hypoglycemic. Interestingly, when hypoglycemia was treated nutritionally in one study, 71 percent of alcoholics became sober.

The Microbiome and Mood

The microbiome is the inner bacterial ecosystem within each of us. Our bacteria outnumber our own human cells nearly 10-fold. Beyond the well-known digestive and immune-stabilizing impact of healthy gut flora balance are stunning new revelations regarding mood and behavior. The National Institutes of Health’s Human Microbiome Project, launched in 2007, has resulted in game-changing findings about bacterial impacts on human psychology. Most incredibly, it was discovered that bacteria not only synthesize the same neurochemicals that drive our thoughts and behaviors, such as serotonin and dopamine, but they also communicate with the brain via those chemicals. Imagine that!

A recent flurry of studies, mostly on rodents, show beneficial bacteria’s therapeutic effects on depression, autism, repetitive behaviors, anxiety, and more. One of the most fascinating of these studies showed that calm mice that were fed fecally-derived bacteria from anxious mice became anxious. Want to guess what happened when anxious mice were fed bacteria from calm mice? You guessed it: they turned into calm mice. A bit surreal isn’t it? Human research is still preliminary, but prescription ‘‘psychobiotics,’’ whereby specialized bacteria will be given to treat psychological disorders of all kinds, may become a reality in the not-too-distant future.

However, there are already powerful therapies for our microbiome on vitamin store shelves—pre- and probiotics. Fermented foods like sauerkraut are also a source of good bacteria. One of the many benefits of probiotics in supplements and foods is that they assist the body in producing significant amounts of the relaxing neurotransmitter GABA.

Even those mood-destabilizing blood sugar swings can be influenced by our microbiome, according to nutritionist Martie Whittekin, who cites in her new book, The Probiotic Cure, that a recent review of 12 studies found that the use of multistrain probiotics may help glycemic control.

The Right Kinds of Fat

Fat makes up 60 percent of our brains, and omega-3 fats, cholesterol, and saturated fats are key brain builders. DHA and EPA fatty acid deficiencies cause brain cell communication failures and inflammation, affecting virtually all mood disorders. Low-saturated-fat and low-cholesterol diets are linked with higher rates of depression, infertility, and dementia.

It was scientifically flawed data that falsely concluded that dietary cholesterol leads to cardiovascular risk. Low-cholesterol status is linked with serotonin dysfunction, increased suicides, accidents, violence, and impulsiveness. High cholesterol actually correlates with better memory in elderly people, and lowered aggression and increased social behavior in nonhuman primates.

And think of this before ordering your next egg white omelet: cholesterol is the raw material, not only for the body’s production of vitamin D, but for our sex hormones, bolstering libido and fertility. Another important brain nutrient for memory and cognition, also found in egg yolk, is choline. So you might be crazy to keep ordering egg white omelets. Literally.

Why Leptin is Key

One of the unexpected side benefits of the low-sugar, high-fat diet I advocate is restored leptin sensitivity. The proper functioning of the hormone leptin is known to influence satiety signals in the body. Personally, leptin balance has been my greatest key to escaping what felt like was mood and food prison. Beyond increasing feelings of satisfaction after eating, leptin affects personality in myriad ways.

This hormone has been shown to heal dopamine pathways (often resolving addiction); balance the sympathetic and parasympathetic nervous systems (restoring calmness, clear thinking, deep sleep, and digestion); restore thyroid, adrenal, and sex hormone function (reviving energy, libido, and countless other happiness-boosters); reduce body-wide inflammation (reducing a known contributor to depression as well as all kinds of pain); and actually grow the cerebral cortex (our self-control center). And interestingly, it was recently shown to have a direct influence on the composition of gut bacteria.

My own personality today is completely different from that of the deeply troubled, overly sensitive, ashamed, self-isolating, and addicted woman I was 30 years ago. Helping others navigate this miraculous transition in my workshops has been my focus for nearly two decades, and during that time, I have witnessed truly incredible transformations, both physically and emotionally.

So do I believe mood and behaviors—in essence, your personality—can really be altered by changing your diet and taking certain supplements? My own transformational experience, and the observations of the transformations of my clients over nearly two decades have convinced me that it is indeed possible, and new discoveries in science are proving it.

One of the many benefits of probiotics in supplements and foods is they assist the body in producing significant amounts of the relaxing neurotransmitter GABA. 

Personality Makeover

I’ve seen countless examples of nutrition profoundly changing people emotionally as well as physically in my workshops. I’ve heard everything from “My kids tell me they can’t push my buttons anymore” to “I no longer get angry when cars cut me off in traffic.” One example is my client Cathy Froncek, 57, of San Francisco, who recently completed one of my workshops. Cathy had this to say about her emotional experience: “After several days of changing my diet—including some rough initial ‘sugar detox’ days during which I felt particularly emotionally vulnerable—I felt a sudden calm like I had never felt. Then over the next weeks, I started seeing things about myself that I didn’t like that became glaring. I began to just say what I was feeling or needed to my husband and kids instead of manipulating or being passive aggressive. It was so new (and at times, uncomfortable) that we had to relearn how to relate to each other. Now I can say that I’m actually far more real and down to earth, and our relationships are much richer. At work, I’m not a control freak or micromanaging anymore. I’m so much more laid back. I laugh much more. And the physical changes such as weight loss and better skin health have improved my self-image. I can’t believe the difference!”

Cathy’s “before” kind of reminded me of my “before” 30 years ago (see below, now and then).

Cathy before personality makeover

Cathy's "after"

Cathy before personality makeover

Cathy's "before"

Cathy after personality makeover

Kat's "after"

Kat before personality makeover

Kat's "before"

Supplemental Support

The following are a few of the supplements known to support common nutrient deficiencies that an influence mood and behavior that I often recommend to my clients.

The following are a few of the supplements known to support common nutrient deficiencies that an influence mood and behavior that I often recommend to my clients. Editor’s Note: Consult your doctor before taking supplements if you’re pregnant or being medically treated, and never discontinue medication without your doctor’s supervision. For guidance on nutritional treatments for specific mood issues, visit Other recommended reading: Depression-Free Naturally and Seven Weeks to Sobriety by Joan Matthews Larson. Stick with package-recommended dosages unless otherwise directed by your health practitioner.

B-Complex Vitamins

In one study, supplementation of NAD, a form of niacin (vitamin B3) halted most alcohol withdrawal symptoms within four days. Niacin has shown benefit in some types of schizophrenia, alcoholism, and severe depression. B1 deficiencies correlate with depression, poor memory, and insomnia.

Blood-Sugar-Stabilizing Nutrients

These include chromium, vanadyl sulfate, zinc, and alpha-lipoic acid.

DHA Omega-3 Fish Oil

Boosts dopamine, and improves cognition and mood. Often depleted in postpartum depression, ADHD, and many other cognitive disorders. DHA has been shown to raise dopamine levels.


Inhibits an enzyme that reduces endorphin, a pain-relieving, comforting neurotransmitter that can help many sleep.

Free-Form Amino Acids

Shown to reduce depression, anxiety, addictions, and many other mood disorders by nourishing neurotransmitter synthesis and function; more readily absorbed than long-chain protein sources.

Holy Basil

Reduces anxiety and the stress hormone cortisol.


Needed for thyroid and brain health. Depleted by the prescription antidepressant Prozac.


Encourages calm focus.

Magnesium Threonate

Increases the number of functioning neurotransmitter release sites. Deficiencies can decrease dopamine levels. Helps inflammation and blood sugar metabolism, and calms anxiety.

N-Acetylcysteine (NAC)

Supports liver health and neurotransmitter activity in certain addictions and compulsive gamblers in some studies.


Fortify beneficial bacteria in the gut.


This more absorbable form of B6 helps convert amino acids into neurotransmitters.


Critical for thyroid function.


A calming amino acid that can benefit hypoglycemia and related shakiness (even in alcoholics); assists mineral absorption. Interestingly, a 2015 study showed that taurine helped preserve the actions of the hormone leptin in mice fed a high-fat diet. Deficiency is widespread in addicts and older people.


Key thyroid hormone and dopamine function building block. Improves focus, energy, and depression. It can be stimulating, so use earlier in the day, and under a doctor’s supervision if you’re being treated for heart or hypertensive issues.


Zinc deficiency is linked to a wide array of mood and cognitive problems. Look for ionic zinc, which is better absorbed.


Helps boost serotonin. May lift mood and deepen sleep.

Recommended Products

Just Thrive Probiotic and Antioxidant

Just Thrive Probiotic & Antioxidant

is a proprietary blend of unique spore-forming bacillus strains guaranteed to reach the gut intact and promote favorable bacterial balance.

Nordic Naturals Ultimate Omega

Nordic Naturals Ultimate Omega

features high levels of EPA and DHA omega-3s—more than 1,200 mg combined—in just 2 softgels.

Ecological Formulas Free-Form Amino Acids

Ecological Formulas Free-Form Amino Acids

provides all 21 essential and nonessential amino acids, shown to reduce depression, anxiety, and other mood disorders.

Wakunaga Kyolic Blood Sugar Balance

Wakunaga Kyolic Blood Sugar Balance

is formulated with chromium and a blend of herbs known to support healthy blood sugar levels.

Source Naturals Serene Science 5-HTP

Source Naturals Serene Science 5-HTP

contains 5-HTP naturally derived from the seeds of the African Griffonia simplicifolia plant, shown to increase serotonin levels and promote emotional well-being.

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