When it comes to managing ADHD symptoms, we often overlook one of the most fundamental factors: what we eat. Today, I’m sharing insights from my conversation with Catherine McCrory, a nutritional therapist diagnosed with ADHD at 35 who specializes in nutrition for women’s health and the menstrual cycle.
The ADHD-Nutrition Connection
One of the most striking things Catherine shared is how dramatically nutrition can impact ADHD symptoms. As someone who experienced this firsthand when I addressed my insulin resistance years ago, I can attest to the profound changes that dietary shifts can bring. When I moved to a higher protein, lower carbohydrate diet, not only did my fatigue improve, but my executive function skills—which tank with any kind of fatigue—got significantly better.
Why Protein Matters for ADHD Brains
Catherine is “really hot on protein” for her ADHD clients, and for good reason:
Blood Sugar Balance
Protein helps balance blood sugar levels throughout the day, providing steady energy instead of the peaks and crashes that can wreak havoc on ADHD symptoms. Catherine recommends:
- 25-30g of protein at each meal (breakfast, lunch, and dinner)
- Including protein in every snack
The Dopamine Connection
Here’s the fascinating part: protein contains amino acids, particularly one called tyrosine, which is the precursor to dopamine. Since ADHD is associated with lower or fluctuating dopamine levels, feeding your brain the building blocks it needs to produce this crucial neurotransmitter is essential.
What 30g of Protein Looks Like:
- Chicken: About one palm-sized chicken breast
- Eggs: 3-4 egg omelet (consider adding smoked salmon for extra protein)
- Plant-based: You’ll need 2-3 sources (lentils + nuts/seeds + hummus) since plant proteins also contain carbohydrates
The Menstrual Cycle’s Impact on ADHD
For those who menstruate, Catherine revealed something crucial: executive function changes throughout the month based on hormonal fluctuations.
The Four Phases:
- Menstrual Phase: Period/bleeding
- Follicular Phase: High estrogen = better executive function (estrogen stimulates dopamine and serotonin)
- Ovulation: Generally good executive function
- Luteal Phase: Progesterone-dominant, more challenging for executive function, requires 100-300 additional calories
“Progesterone is quite a calming hormone, but it can be more challenging in terms of executive function. It doesn’t particularly like high stress levels,” Catherine explained.
The Brain Fog Mystery
Brain fog is a common complaint, especially among women with ADHD. Catherine identified several nutritional culprits:
Common Causes:
- Low iron: Especially common in menstruating individuals
- Low B12 or folate
- Elevated cortisol from chronic stress
- Insufficient protein intake
“I’ve seen four clients this weekend, and every single one of them had low iron levels,” Catherine shared. “It’s so commonly missed.”
Key Supplements for ADHD
Catherine recommended several supplements that can support ADHD brains:
1. B-Vitamin Complex
- Supports nerve transmission
- Can be depleted by stress
- Take in the morning (they’re stimulating)
- May help with mood and energy
2. Magnesium
- Involved in over 300 body reactions
- Depleted by stress
- Catherine recommends magnesium bisglycinate, 300mg
- Take an hour before bed to help with sleep
3. Omega-3 Fatty Acids
- Important for brain health and executive function
- Reduces inflammation
- Eat oily fish 2-3 times weekly (salmon, mackerel, sardines, anchovies, herring – remember SMASH)
- Or supplement with fish oil or algae oil
4. Lion’s Mane Mushroom
- Boosts brain-derived neurotrophic factor (BDNF)
- Helps brain cells communicate
- Acts as a prebiotic for gut health
- Take as a capsule in the morning
The Importance of Nervous System Support
Before diving into nutritional changes, Catherine often focuses on calming her clients’ nervous systems. Many ADHD adults are in a constant state of stress, trying to keep up with neurotypical expectations while managing additional challenges.
Simple Breathing Exercise: Box Breathing
- Inhale for 4 counts
- Hold for 4 counts
- Exhale for 4 counts
- Hold for 4 counts
- Repeat for 5-10 minutes daily
“Just that technique, just like 5 to 10 minutes a day, it’s so calming for people’s nervous systems,” Catherine noted.
The Individual Approach
One crucial point Catherine emphasized: nutrition and supplementation need to be personalized. What works for one person may not work for another, especially in the neurodivergent community.
“I find a lot of times… something I’d give to a neurotypical client would be fine. When I give to a neurodiverse client, they can just feel very stimulated by it,” she explained.
Key Takeaways
- Protein is foundational: Include it in every meal and snack to support dopamine production and blood sugar balance
- Track your cycle: If you menstruate, notice how your executive function changes throughout the month
- Check your nutrients: Low iron, B12, and folate are common and can significantly impact ADHD symptoms
- Consider targeted supplements: But always check with your healthcare provider for interactions
- Don’t forget nervous system support: Sometimes addressing stress is more important than nutritional changes
- Personalization matters: Work with a professional who understands both nutrition and neurodiversity
A Note on Quality
When choosing supplements, Catherine emphasized the importance of quality. Look for companies that do third-party testing to ensure:
- The supplement contains what it claims
- There are no contaminants
- Minimal fillers and binders
Remember: supplements should support a nutritious diet, not replace it. And consistency matters—Catherine recommends giving supplements at least 12 weeks to show effects.
Catherine McCrory is a nutritional therapist specializing in women’s health and the menstrual cycle. You can find her on Instagram @naturalcyclesnutrition and book a free discovery call through her profile. She offers online consultations worldwide.
Have you noticed connections between your nutrition and ADHD symptoms? What dietary changes have made a difference for you? Share your experience in the comments below.
