Anxiety, Brain Fog, and Depression: The Surprising Link to Insulin Resistance and How to Fix It

A powerful and consistent theme across the raw comments is the profound, often unexpected, improvement in mental health after adopting a low-carb or ketogenic diet. Viewers share deeply personal stories of suffering for years with anxiety, treatment-resistant depression, and debilitating brain fog, only to find dramatic relief once they stabilized their blood sugar. This is not just a side benefit; for many, it is the most life-changing outcome. The audience is connecting the dots themselves, realizing that their mental state is not separate from their metabolic state and that the brain, as a high-energy organ, is exquisitely sensitive to the fuel it receives.

The core concern is that the medical system often treats mental and metabolic health in separate silos. Viewers are frustrated that for years their doctors never suggested a link between their diet and their depression or anxiety. They were prescribed psychiatric drugs but were never told that insulin resistance could be a contributing factor. This leaves them feeling that a fundamental piece of their health puzzle was ignored, forcing them to discover this powerful connection through their own research on platforms like YouTube.

The most crucial insight is that stabilizing your blood glucose should be a foundational strategy for improving mental and cognitive health. The brain requires a steady supply of energy to function optimally. Glucose spikes and crashes create an erratic fuel supply, stressing the brain's mitochondria and driving inflammation, which can manifest as brain fog, irritability, anxiety, and depression. Providing the brain with a more stable fuel source, like ketones, can lead to dramatic improvements in mood and mental clarity.

Several creators directly explained the link between glucose control, insulin resistance, and various aspects of brain health, from daily cognition to chronic neurological conditions.

• • Dr. Benjamin Bikman (on The Diary Of A CEO): He provides a detailed scientific explanation of how insulin resistance impacts the brain.
  • ◦ Clarity & Depth: He explains that many neurological disorders, including depression, migraines, and epilepsy, have "brain glucose hypometabolism" in common—meaning the brain isn't getting enough energy from glucose. He calls Alzheimer's disease "insulin resistance of the brain," clarifying that certain parts of the brain need insulin to let glucose in, and when that process fails, the brain starves.
  • ◦ Actionable Advice: He positions ketones as a superior fuel for the brain, noting that the brain thrives on them and immediately starts using them for energy when available. He highlights studies where people with early-stage Alzheimer's showed improved cognitive function (like being able to tie their shoelaces again) when in ketosis.
• • Jessie Inchauspé (Glucose Goddess): She focuses on the immediate, tangible effects of glucose spikes on daily mental performance.
  • ◦ Clarity & Depth: She explains that glucose spikes cause mitochondrial stress, which leads to chronic fatigue and brain fog. She cites a study linking glucose roller coasters to increased irritability and puts forth a study linking insulin resistance developed over 10 years to a twofold increase in major depression.
  • ◦ Actionable Advice: Her hacks, like having a savory breakfast, are designed to create steady glucose levels throughout the day, which she argues is essential for having a "clearer brain" and showing up as the person you want to be.
• • Dr. Robert Lustig: He connects mental health to specific nutrient deficiencies that can arise from certain dietary patterns.
  • ◦ Clarity & Depth: He explains that tryptophan, an amino acid often low in vegan diets, is the precursor to serotonin (the "happiness neurotransmitter"). A deficiency can be associated with irritability and depression. He also links omega-3 deficiency to depression.

Instead of a sugary or starchy evening snack, have a handful of nuts or a piece of cheese. This will help keep your glucose stable overnight, preventing a morning crash and setting you up for better mental clarity the next day.

• Mistake: Reaching for sugar or carbs for a quick energy boost when feeling tired or foggy.
  Fix: Recognize this as a symptom of the glucose roller coaster. As Jessie Inchauspé explains, the "rush" is from dopamine, not real energy, and it makes the underlying mitochondrial stress worse. Drink a glass of water and wait for the feeling to pass or have a low-carb snack.
• Mistake: Thinking that a "healthy" fruit smoothie is a good choice for mental clarity.
  Fix: Understand that pulverizing fruit removes its protective fiber, leading to a large glucose spike that can worsen brain fog and fatigue. Eat fruit whole instead.
• Mistake: Assuming mental health is completely separate from diet.
  Fix: View your brain as a metabolic organ. The personal stories are powerful evidence that what you eat directly and profoundly impacts how you feel. Start treating your diet as a primary tool for mental wellness.

• • “Carnivore cured my IBS, anxiety, depression, skin issues and so much more.”
• • “The discussion on carb addiction is very interesting to me as I will eat healthy and then have fallen into carb/sugary binging and have trouble stopping.”
• • “My morning glucose reading was 6.0 mmol. I am always hungry, sometimes I even binge, I have afternoon crashes, headaches..memory issues. So I am really scared I have it...”
• • “My A1C is 5.2 and the recent blood work reports that my insulin resistance is low, BUT for YEARS, my blood sugars have been 101-113 range... I'm baffled as is my doctor as to why my fasting glucose levels are constantly high. Any thoughts?”

The raw comments reveal a powerful, grassroots discovery: the food on your plate has a direct and profound impact on your mental and emotional well-being. For years, the conversation around mental health has been separated from metabolism, but viewers are now providing compelling evidence that stabilizing blood sugar and fueling the brain correctly can be a life-changing intervention for anxiety, depression, and brain fog. This points to a new frontier where metabolic health is not just an adjunct to, but a cornerstone of, effective mental healthcare.