When we think about ADHD, we usually think about the brain: focus, impulsivity, restlessness. But new research is revealing something surprising—ADHD doesn’t solely affect how you think, it also affects how your body works, especially how it processes nutrients.
A recent May 2025 genetic study found that people with ADHD have meaningful, biologically-driven differences in their metabolism, especially in how they process omega-3s and protein, using “Reverse Mendelian randomization,” which looks at cause-effect relationships using DNA.
Simply put: ADHD is linked to changes in the body’s internal chemistry, not just the brain’s wiring.
What are Metabolites Anyway?
Metabolites are substances like amino acids and vitamins that your body creates while breaking down food and other compounds. As several studies have shown specific metabolites linked to conditions like dementia and bipolar disorder, the researchers in this study wanted to dig deeper into plasma metabolites that have been causally linked to ADHD in previous studies.
Previous studies showed varied levels of metabolites in those with ADHD. With some showing higher and some lower, most metabolites identified play crucial roles in brain health, emotional regulation, and energy levels.
This proves that ADHD isn’t just in our brain—it’s in our body, too. Let’s look at some key metabolites we need to pay attention to.
Amino Acids: Protein Required
Protein isn’t just about muscles—it’s about messages. Your brain uses amino acids, a metabolite created when the body breaks down protein, to create neurotransmitters like dopamine, serotonin, and norepinephrine. Unfortunately, studies have shown that people with ADHD have disruptions in protein metabolism. The research found that for people with ADHD:
- How the body breaks down and uses amino acids is different than people without ADHD
- Energy supply to cells through protein pathways is altered
- Protein-related waste and recycling may not function properly
Essentially, the ADHD body requires more protein than normal, simply because our bodies do not use protein correctly. I encourage people to eat between 1.2-1.6g of protein per kg of body weight per day in my eBook, The ADHD Diet. If you struggle with taking all this information into practice, I’ve created clear guidelines to tell you exactly what to do for the best results without all the confusion!
Aminos and Antioxidants: To Detox
Your detox systems—especially in the liver—depend heavily on amino acids and antioxidants to break down toxins, hormones, and even your own neurotransmitters. These pathways rely on methylation, glutathione (aka the “master antioxidant”) production, and fat metabolism. Unfortunately, these studies found that these pathways are also affected:
- ADHD causes lower levels of nicotinuric acid and inosine, suggesting a reduced ability to break down fat and maintain cellular energy
- ADHD causes disruptions in taurine and methionine metabolism, which are key players in your body’s main antioxidant defense system
- ADHD causes increases in cholic acid, which means the body’s ability to process fats (especially omega-3s) is disrupted
This means if you have ADHD, your body might be slower or less effective at clearing out stress hormones, excess neurotransmitters, or inflammatory byproducts…which could leave you feeling foggy, drained, or reactive.
Omega-3s: Brain Health
EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are omega-3 fatty acids found in fish oil, and they’re essential for brain health. But according to this study, people with ADHD are less efficient at using or retaining these fats.
The genetic study found that these fats are bi-directionally causally linked, which means low levels can cause ADHD (aka worse/increased symptoms), and having ADHD can cause low levels (aka ADHD affects how our body metabolizes the fats). These fats are critical for:
- Neurotransmitter signaling (especially dopamine)
- Reducing brain inflammation
- Maintaining membrane flexibility in neurons
Unfortunately, even though we know that ADHD is connected with worse omega-3 metabolism, omega-3 supplements do not help ADHD. The likely reason for this is the quality of the supplement. Most omega-3 supplements on the market are expired: Omega-3s are chemically unstable, meaning by the time they are created, packaged, and sent to you, they’re already bad and could be making your body worse. One sign is if you get the fish oil burps—that is NOT supposed to happen!
If you want to take an omega-3 supplement, check if it contains additional antioxidants or is mixed with olive oil. Those two have been studied to improve how the body uses the supplement. Better, even, is to simply eat enough fish.
Important Takeaways
When you live with ADHD, it’s easy to feel like your brain is the problem. But what if part of what you’re feeling isn’t just mental—it’s metabolic?
This study shows that ADHD changes how your body breaks down protein, clears out stress, and uses omega-3s. This means even if you’re eating all the right things, your body might not be processing them the way it should. That can show up as foggy thinking, low energy, irritability, or feeling like nothing is working.
The good news? You’re not doing anything wrong. Your body just needs a different kind of support. That’s why I created The ADHD Diet. It’s the only eBook on the market that tells you exactly what to do to help your ADHD using nutrition, according to science. It gives you clear steps and real food strategies that truly match how your body operates.
Because when you match your metabolism differences to your eating habits, everything else gets a little easier.
Not on ADHD meds – or can’t take them? Let’s start with food.
The ADHD Eating Guide is a research-informed toolkit designed to support ADHD brains through nutrition and behavior. Whether you’re off meds, in between prescriptions, or just want to feel better day to day, this revolutionary 6-part bundle offers simple, evidence-based strategies that actually work with your brain.
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The ADHD Meal Guide
Learn the science behind eating for ADHD and how to start.
The 5 ADHD Food Families
Discover the top nutrients linked to symptom relief (with easy ways to get them in).
ADHD Eating Hacks
10 behavioral strategies grounded in psychology to help you eat when you “just can’t.”
The ADHD Meal Builder
The novel no-brainpower-needed way to build balanced meals.
The ADHD Example Menu
80 ADHD-friendly meal and snack ideas sorted by effort level.
The ADHD Grocery Plan
A weekly grocery tool that simplifies planning, cuts decision fatigue, and actually works with your brain.
P.S. I cut through the noise to bring you what really works – no pseudoscience, just evidence-based nutrition strategies for ADHD.
