When it comes to understanding violent or aggressive behavior, we often focus on psychology or environment. But there’s a hidden factor most people overlook: diet.
Read: Another perspective on understanding anger
Recent studies suggest that junk food consumption can influence emotional stability, aggression, and even violent tendencies—especially among teens and young adults.
In this article, we explore what the science says about the link between junk food and violent behavior and what you can do about it.
How Junk Food Affects Brain Health and Emotional Regulation
Junk food is typically high in:
- Refined sugar
- Saturated fats
- Artificial additives
- Salt and preservatives
It is low in essential nutrients like:
- Omega-3 fatty acids
- Magnesium, zinc, and iron
- Vitamins B6, B12, D, and folate
These nutrients are critical for brain function and impulse control.
Without them, people—especially adolescents—are more prone to irritability, emotional instability, and impulsive behavior.
Research-Backed Evidence Connecting Junk Food and Aggression
1. Ultra-Processed Foods and Bullying in Teens
A large-scale Brazilian study linked consumption of ultra-processed foods (snacks, soda, packaged sweets) with increased bullying and deviant behavior in adolescents.
“Deviant behaviors accounted for nearly 40% of the psychological aggression observed.”
2. Western Diet Patterns and High Aggression Scores
In an Iranian study of teenage girls, adherence to a Western diet (fast food, sugar, soft drinks) was significantly associated with higher levels of aggression.
3. Fast Food and Anger: A Two-Way Street
A U.S.-based longitudinal study of young adults (18–28) found that:
- Frequent fast food consumption predicted future anger episodes
- Anger and irritability also predicted future junk food cravings
Biological Mechanisms: How Junk Food Can Trigger Aggression
1. Neurotransmitter Disruption
Nutrient deficiencies impair dopamine and serotonin, affecting mood and impulse control.
2. Brain Inflammation
Processed food increases inflammation in the brain, particularly in areas tied to emotional regulation (like the amygdala).
3. Blood Sugar Crashes
High sugar intake causes mood swings, fatigue, and irritability, creating the perfect storm for emotional outbursts.
4. Gut–Brain Axis Breakdown
Diets low in fiber and micronutrients disrupt gut microbiota, reducing mood-regulating short-chain fatty acids.
Junk Food and Violence in Correctional Facilities
Several studies have shown a strong link between improved nutrition and reduced aggression in prisons:
Inmates given better diets and supplements experienced up to a 45% drop in disciplinary infractions.
A UK study published in the British Journal of Psychiatry showed a 26.3% reduction in violent behavior with dietary changes.
Study Review – PMC10888116
Adolescents Are Most at Risk
Teenagers are especially vulnerable because:
- Their brains are still developing
- Emotional regulation centers (like the prefrontal cortex) are still maturing
- They often consume the highest levels of junk food
Combined with academic pressure and hormonal shifts, this makes them more susceptible to aggression linked to poor diet.
What Can Be Done? Solutions and Interventions
1. Promote Whole Foods in Schools
Replace vending machines with fruit, nuts, and yogurt.
2. Nutrition Education
Teach students and parents how food affects behavior, not just physical health.
3. Reform Institutional Food Systems
Prisons, schools, and group homes should integrate brain-healthy meals.
4. Support Further Research
Government and academic institutions should invest in more studies on diet and aggression.
Is Junk Food Making Us Mean?
While junk food doesn’t cause violent behavior on its own, it amplifies emotional instability, especially in already vulnerable populations.
With mounting evidence showing the connection between junk food and violent behavior, it’s time to treat diet as a public mental health issue—not just a physical one.
Dr. Matsumoto’s comments:
As a person who was raised on junk food in the 1960s, I find the recent research that has begun to undercover the possible close connection between diet and what happens in our gut and many different physical and mental health outcomes incredibly interesting and important.
The fact that there may be a link between junk food and how we regulate our emotions and behavior is not surprising to me.
That especially reinforces for me the thought that improving our emotional intelligence and wellness – both physically and mentally – starts with having better wellness baselines.
These wellness baselines revolve around six domains:
No matter what techniques we engage in to improve our emotional intelligence – breathing, meditation, critical incident analysis, whatever – their effects are all magnified by having better wellness baselines in the first place.
Of course making changes in anything we’ve done all our lives is difficult, whether in our lifestyle of emotional styles.
Perhaps we can start by making one small change, like cutting out that soda or bag of chips once a week. Even a journey of a 1,000 miles begins with the first step!
The post Junk Food Fuels Violence? The Science of Diet & Aggression first appeared on Humintell | Master the Art of Reading Body Language.
These findings breathe new life into the longstanding facial feedback hypothesis—the idea that our facial expressions can shape how we feel.
If you’re curious about applying this to everyday life:
When it came to how quickly the brain responded to faces, the researchers found no meaningful differences in 5 or 10-month-old infants between those tested before and during the pandemic.
One of the most striking findings emerged when the researchers examined how children responded to emotional expressions.
The results of this study are not surprising, given the growing number of studies demonstrating the negative and somewhat deleterious effects of the use of masks on facial emotional expression recognition and identification in young children.