I have an ADHD teen and good diet absolutely can improve symptoms and functioning - just like it can with every other health issue - diet isn’t a cure but it helps.
there’s a lot of things about ADHD that many don’t realise.
the dopamine seeking behaviour is huge. My teen seeks the dopamine high from eating sugar. I bake cookies and cakes and flapjacks with real sugar and fruit and butter and chocolate. I choose wisely and avoid products with certain E numbers because the do have a negative effect. Thankfully in the U.K. the E numbers that have an adverse effect on kids and adhd are limited but the do exist. Our local American candy store is a nightmare for DC who wants it all!
the only sugar free products we use is sugar free cordials because ADHD teen also has sensory issues and won’t drink water. Any drink is better than no drink. A dehydrated kid is a monster we do not want to unleash.
forgetting to eat is a huge issue with adhd. Even more so when medicated.
I make sure meals are as rounded as possible with high protein for good blood sugar control and try to limit binging of carbs. Which happens when you’ve gone all day without eating because the meds suppress your appetite and adhd hyper focus means you forget to eat.
Caffeine sends my teen to sleep. That throws people off, sending teen to bed having an espresso but I’d rather a cup of coffee than dosing with melatonin.
on a related note we all feel awful on junk/UPF/low nutrient Foods. We have brain fog, sluggishness, irritability/anxious feelings, trouble sleeping, exhaustion. All of this can mimic many adhd symptoms and this can be resolved with better diet.
so yes anyone with adhd should fix their diet first to filter through what symptoms are caused or made worse by diet and which will need other treatments such as medication. Food can improve things if done right.
but it doesn’t cause it. Diet is part of the whole treatment plan.