Neurologist David Perlmutter recently shared a powerful message on X:
Snacking isn’t the problem. Snacking on ultra-processed carbs is. Simple upgrades like nuts, seeds, yogurt, or eggs can support focus instead of brain fog.
It challenges the common belief that eating between meals automatically harms metabolism or cognitive performance. The real issue may not be when you snack, but what you snack on. Let’s break down the science behind ultra-processed carbohydrates, brain fog, and smarter snack choices.
Why ultra-processed carbs trigger brain fog
Ultra-processed carbohydrate snacks, such as packaged pastries, white crackers, candy bars, and sugary granola bars, digest rapidly and cause sharp spikes in blood sugar.
This surge is often followed by a quick drop, leading to:
- Fatigue
- Reduced focus
- Irritability
- Increased cravings
These fluctuations strain metabolic balance and may increase inflammation over time. Repeated glucose spikes have also been linked to impaired cognitive flexibility and reduced sustained attention. In short: the crash, not the snack, is the problem.
Smart snack upgrades that support focus
Perlmutter suggests replacing ultra-processed snacks with whole-food alternatives like:
- Nuts and seeds, rich in healthy fats, magnesium, and fiber
- Plain yogurt, provides protein and gut-supportive probiotics
- Eggs, offer high-quality protein and choline, essential for brain function
These options slow digestion, stabilize blood sugar, and provide nutrients that directly support neurotransmitter production and cellular energy. Balanced snacks combining protein, fat, and fiber help maintain:
- Steady glucose levels
- Sustained concentration
- Reduced inflammation
- Longer satiety
Instead of creating a dopamine spike followed by a crash, they provide metabolic consistency.
