Researchers looked at 50 different studies involving over 2,000 young people to see if eating healthier food or taking vitamins could reduce aggressive and antisocial behavior. They found that making broad changes to diet—like eating more nutritious foods overall—showed the most promise, with benefits ranging from small to large depending on the behavior being measured. Interestingly, changing what kids eat worked better than just giving them supplements. While the evidence isn’t perfect, the researchers say these nutrition changes are safe, affordable, and worth trying since good nutrition helps both physical and mental health anyway.

The Quick Take

  • What they studied: Whether improving nutrition through diet changes or supplements could reduce aggressive behavior, antisocial actions, and criminal behavior in children and teenagers
  • Who participated: Over 2,000 young people (up to age 24) across 50 different studies who showed higher-than-normal levels of aggressive or antisocial behavior
  • Key finding: Broad nutritional improvements (like eating better overall or taking multi-nutrient supplements) reduced aggressive behavior by about 31% and antisocial behavior by about 49%, with diet changes working much better than supplements alone
  • What it means for you: Improving a young person’s diet may help reduce aggressive and disruptive behavior, though this works best as part of a bigger approach to health. This is especially promising because good nutrition helps with many other health issues too, making it a practical, safe, and affordable option worth considering.

The Research Details

This is a meta-analysis, which means researchers searched through published and unpublished studies from February 2024 and earlier, looking for controlled experiments that tested whether nutrition changes affected aggressive or antisocial behavior in young people. They found 50 studies total and combined the results to see the overall pattern.

The researchers were very careful about which studies they included. They only looked at studies where young people actually showed aggressive behavior in real-life situations (not just in games or simulations), and where the nutrition intervention lasted at least a week. Two independent reviewers checked each study to make sure it met these standards and to assess how well the study was designed.

To combine results from different studies fairly, the researchers converted all the findings into a standard measurement called ’effect size,’ which lets you compare apples to apples even when different studies measured things slightly differently. They also looked at which studies might have quality problems that could affect the results.

This research approach is important because aggressive and antisocial behavior in young people can cause serious problems—damaged relationships, school failure, and long-term negative effects on their lives and society. If nutrition could help reduce these behaviors, it would be a game-changer because it’s safer and cheaper than many other treatments. By combining 50 studies, the researchers could see patterns that wouldn’t be obvious from looking at just one or two studies.

This is a high-quality systematic review published by the Campbell Collaboration, which sets strict standards for research reviews. However, readers should know that when the researchers removed studies with quality problems, the benefits got smaller—especially for aggression. This suggests some of the original findings might be overstated. Also, the studies showed a lot of variation in their results, meaning nutrition interventions don’t work the same way for everyone.

What the Results Show

The biggest finding was that broad nutritional approaches—meaning either improving overall diet quality or taking multi-nutrient supplements—worked best. For aggression, these broad approaches reduced it by about 31%. For antisocial behavior, the reduction was about 49%. For criminal offending, the reduction was even larger at 125%, though this was based on only 2 small studies, so we should be cautious about this number.

Importantly, changing what kids ate worked much better than just giving them supplements. When researchers looked only at high-quality studies (removing ones with potential problems), the benefits for aggression shrank to almost nothing, and benefits for antisocial behavior became smaller. This is an important caution: some of the positive results might have been due to study design problems rather than the nutrition actually working.

Omega-3 fatty acids (a type of healthy fat found in fish) were the most commonly studied supplement. They showed a small benefit for aggression and antisocial behavior, but the results weren’t consistent across studies. Vitamin D supplements showed a small-to-moderate benefit for antisocial behavior, but again, this benefit got smaller when researchers removed lower-quality studies.

The researchers also looked at what makes it hard or easy to actually use these nutrition interventions in real schools and communities. They found many barriers (like cost, time, and getting kids to actually eat healthier) and facilitators (like having school support and making it easy for families). This practical information is important because even if nutrition works, it only helps if people can actually do it.

This research adds to a growing body of evidence suggesting that nutrition affects mental health and behavior, not just physical health. Previous smaller studies hinted at benefits, but this large review shows the effects are real but modest—especially for aggression. The finding that broad diet changes work better than single supplements is new and important information that hadn’t been clearly shown before.

Several important limitations exist. First, many of the studies included had quality problems that made their results less trustworthy. Second, the studies showed huge variation in their results—some found big benefits while others found none—suggesting nutrition interventions don’t work the same for everyone. Third, some studies were small, which makes the overall results less reliable. Fourth, the researchers couldn’t always tell if the benefits came from the nutrition itself or from other factors like increased attention from researchers. Finally, most studies were short-term, so we don’t know if benefits last over months or years.

The Bottom Line

Based on this research, improving overall diet quality appears to be a reasonable, safe approach worth trying for young people showing aggressive or antisocial behavior—especially as part of a broader treatment plan. This is a low-risk recommendation because good nutrition helps with many other health issues anyway. However, don’t expect nutrition alone to solve behavior problems; it should work alongside other approaches like counseling or behavioral support. Taking single supplements like omega-3 or vitamin D alone shows less consistent benefits and shouldn’t replace other treatments. Confidence level: Moderate for broad diet improvements, Low for single supplements.

Parents, teachers, and counselors working with young people who show aggressive or disruptive behavior should consider nutrition as one tool in their toolkit. School administrators might use this to justify investing in better school meals. However, this research doesn’t apply to young people without behavior problems—good nutrition is important for everyone, but this study specifically looked at those with aggression issues. People shouldn’t use nutrition as a replacement for professional mental health treatment when that’s needed.

Most studies lasted weeks to a few months. Based on this, you might expect to see some changes in behavior within 4-12 weeks of improved nutrition, though changes are likely to be gradual rather than dramatic. Some benefits might appear sooner (within 2-4 weeks), while others take longer. Keep in mind that nutrition is one factor among many affecting behavior.

Want to Apply This Research?

  • Track daily nutrition quality using a simple 1-10 scale (1=mostly junk food, 10=mostly whole foods) alongside weekly behavior check-ins (frequency of aggressive incidents or rule-breaking). Look for patterns over 4-8 week periods rather than day-to-day changes.
  • Start with one specific, achievable nutrition change—like adding one serving of vegetables daily, replacing sugary drinks with water, or including protein at each meal. Track this change consistently while also monitoring behavior. Once one change becomes a habit, add another.
  • Use a weekly tracker showing nutrition improvements and behavior observations. Take photos of meals to document diet changes. Note specific behavior improvements (fewer arguments, better focus, calmer responses to frustration). Review progress monthly to see if patterns emerge. Share data with healthcare providers or counselors to inform broader treatment plans.

This research suggests nutrition may help reduce aggressive behavior in young people, but it is not a substitute for professional mental health treatment, medical advice, or behavioral intervention. If a young person is showing serious aggressive, violent, or criminal behavior, consult with a healthcare provider, mental health professional, or school counselor immediately. Nutrition changes should be made as part of a comprehensive approach to health and behavior, not as a standalone treatment. Always consult with a doctor before starting supplements, especially for children and teenagers. Individual results vary, and what works for one person may not work for another.