For years, I thought of junk food as a purely physical problem. Eat too much pizza or ice cream, and you pay for it on the scale or in how your clothes fit. It seemed simple enough: junk food was about the body, not the brain.
But over time—both in my personal life and in my counseling practice—I’ve seen a very different reality unfold. Junk food doesn’t just affect our waistline; it profoundly impacts our mental health.
Christopher Palmer, MD, a Harvard psychiatrist and researcher, lays out the science behind this connection in his groundbreaking book Brain Energy. For years, Palmer treated patients with severe mental health disorders, but the turning point in his career came unexpectedly. One of his patients, who struggled with both schizophrenia and obesity, decided he wanted to lose weight. Palmer put him on a ketogenic diet, expecting to see only physical changes.
What happened next stunned him: not only did the patient lose weight, but his schizophrenia symptoms began to improve dramatically. This single experience changed the way Palmer understood the brain forever. It led him to dive deep into the connection between metabolism, mitochondria, and mental health—a journey that now shapes his life’s work and the powerful research in Brain Energy.
When you understand what Palmer discovered, it’s impossible to look at mental health—or junk food—the same way again.
Your brain only weighs about three pounds, yet it burns through twenty percent of your body’s total energy. It’s like a Lamborghini engine running around the clock. If that engine doesn’t get clean, efficient fuel, things quickly go wrong. At the core of this system are tiny organelles inside almost every cell of your body called mitochondria. These are your body’s power plants. They convert nutrients into energy that keeps every cell functioning, especially the neurons in your brain.
When your mitochondria are healthy and efficient, your brain hums along smoothly. Your mood stays balanced, your focus is sharp, and you’re able to bounce back from stress. But when they falter, everything falters. Palmer’s research shows that mental health disorders—from anxiety and depression to OCD and bipolar disorder—can often be traced back to mitochondrial dysfunction. When your brain’s energy system starts failing, your mental health suffers.
So what does this have to do with junk food? Everything. Ultra-processed foods like soda, chips, fast food, pastries, and candy wreak havoc on your mitochondria and create what Palmer calls a metabolic disaster. It happens in several ways.
First, there’s the sugar spike and crash cycle. When you eat refined carbs or sugary snacks, your blood sugar skyrockets. Your body releases insulin to push that sugar into your cells. If this happens repeatedly, your cells become insulin resistant, meaning they stop responding well to insulin. High insulin levels tell your mitochondria to store energy instead of using it, leaving your brain underpowered—like putting cheap dirty gas in your Lamborghini. The result is brain fog, anxiety, irritability, and emotional instability. That crash you feel after a sugar binge isn’t just in your head. It’s a literal energy crisis happening inside your neurons.
Processed foods also promote inflammation. Industrial seed oils, refined sugars, and additives trigger your immune system. Inflammatory molecules cross into your brain, disrupting neurotransmitters like serotonin and dopamine—the very chemicals that regulate mood. It’s like trying to read a book while someone blares a leaf blower outside your window—you can’t focus no matter how hard you try.
And then there’s your gut, which scientists now refer to as your second brain. Your gut has its own nervous system with over 200 million neurons, connected directly to your actual brain through the vagus nerve—a two-way information superhighway. The trillions of bacteria living in your digestive tract play a starring role in your mental health. They produce neurotransmitters like serotonin, dopamine, and GABA. They regulate inflammation. They even influence cravings, sending chemical signals to your brain that can feel irresistible.
When your gut is out of balance, it sends stress signals to the brain. This overworks your mitochondria and creates a vicious cycle: unhealthy food damages the gut, which damages the brain, which leads to more poor food decisions. This is why so many people feel emotionally trapped when trying to break free from processed foods. It’s not a willpower problem. It’s a biochemical trap.
I’m no stranger to this struggle. Years ago, I lived on a steady diet of pizza, fast food, chips, ice cream, soda—you name it. It was easy, comforting, and honestly, I didn’t think it was a big deal. But what I didn’t realize at the time was how much it was impacting my mood and mindset. I was more irritable and reactive. My anxiety was higher. I felt foggy and exhausted, even when I thought I was getting enough rest.
When I started cleaning up my diet, it wasn’t just about losing weight. I noticed something much deeper: my mental health improved. I was more patient—with my family, my clients, and myself. My thoughts were clearer. I felt more resilient. The biggest surprise was that when I slipped back into old habits, those mental struggles returned almost immediately. The connection was undeniable.
I see this same pattern over and over in my counseling practice. One client, a college student, came to me overwhelmed by racing thoughts and relentless automatic negative thoughts, or ANTs. She assumed it was just how her brain worked. When we tracked her food and mood, a clear pattern emerged. Her anxiety always spiked in the afternoon, right after a blood sugar crash from sugary coffee drinks and processed snacks. When she shifted to a protein-rich breakfast and added a balanced afternoon snack, her ANTs didn’t disappear, but they quieted down enough for her to finally use the coping tools we’d been working on in therapy.
Another layer of this challenge is how our healthcare system is structured. Clients often go to their doctor with mysterious physical symptoms—fatigue, brain fog, anxiety, digestive issues—and leave with few answers. It’s not that doctors don’t care. The problem is time. Most doctors get about ten minutes every few months with a patient. That’s barely enough to scratch the surface, let alone explore the bigger picture.
As a counselor, I spend an hour every week—or every other week—with my clients. We dig into all the interconnected factors that shape their health. I always consider five key avenues about what may be going on when someone comes in to see me: spiritual, emotional, psychological, relational, and physiological.
If we ignore one of these areas, we may miss the root cause of what’s really going on. Doctors tend to focus on the physiological piece alone. Counseling, especially holistic counseling, connects the dots across all five. It’s about understanding the whole person, not just one symptom or one quick fix.
The good news is that you don’t need to overhaul everything overnight. You can start with simple experiments. Begin the day with stable energy by skipping the sugary breakfast and choosing protein and healthy fats instead. Track your meals and moods for a week to see hidden connections between food, energy crashes, and emotional struggles. Replace soda with sparkling water, chips with nuts, and candy with dark chocolate or fruit. Add fiber-rich veggies and fermented foods to support your gut health. And when you slip up, don’t spiral into shame. Get curious: “How did this food affect my mood and thoughts?”
Mental health isn’t just about what happens in your head. It’s about the fuel and systems that power your brain. The next time you find yourself struggling with mood swings, brain fog, or spiraling thoughts, pause and consider what you’ve been eating, how you’ve been sleeping, and what’s happening in your relationships, emotions, and body.
Your brain is a Lamborghini engine—built for precision, speed, and incredible performance. But if you keep pouring cheap fuel into it, don’t be surprised when it sputters, stalls, or breaks down. Junk food might give you a quick burst of energy, but it leaves behind damage that builds up over time, robbing you of clarity, balance, and resilience.
You wouldn’t put the wrong fuel in a Lamborghini and expect it to win a race. Why treat your brain any differently?
Give it the fuel it deserves—because when your brain runs clean and strong, so does your life.
Peace my friends,
~Travis
