The Impact of Sugar Consumption and Ketogenic Diets on Brain Wellbeing

In recent years, the connection between nutrition and mental health has gained significant attention. What we eat doesn’t just affect our physical health; it profoundly impacts our mood, cognitive function, and overall mental wellbeing. However, dietary changes can help to combat these effects, supporting emotional and cognitive resilience. 

The Dark Side of Sugar: How Excessive Consumption Harms Mental Health 

Sugar is everywhere—in sodas, processed foods, and even seemingly "healthy" snacks. While an occasional sweet treat is fine, excessive sugar intake has been linked to an increased risk of depression, anxiety, and cognitive decline. 

• A 2024 meta-analysis published in Frontiers in Nutrition reviewed 40 studies involving over 1.2 million participants and found that higher sugar consumption increases the risk of depression by 21%. 

• Women appear to be more susceptible to sugar-induced mood disturbances, with a 19% higher risk of depression compared to men. 

• While the link between sugar and anxiety was less clear, some subgroups (such as those consuming high sugar via sugary beverages) showed a trend towards increased anxiety risk. 

Why Does Sugar Affect Mental Health? 

• Blood Sugar Fluctuations: Rapid spikes and crashes in blood sugar can lead to irritability, fatigue, and mood instability. 

• Inflammation: High sugar intake triggers systemic inflammation, which has been linked to depression and neurodegenerative diseases. 

• Gut-Brain Axis Disruption: Excess sugar alters gut microbiota, which plays a crucial role in serotonin production—a key neurotransmitter for mood regulation. 

Reducing added sugars—especially from processed foods and sugary drinks—can be a simple yet powerful step towards better mental health. 

Low-Carb and Ketogenic Diets: A Promising Approach for Mental Wellbeing 

While sugar worsens mental health, emerging research suggests that low-carb and ketogenic diets may have the opposite effect—supporting brain function and even alleviating symptoms of psychiatric disorders. 

• A 2024 Stanford pilot study found that a ketogenic diet (10% carbs, 60% fat, 30% protein) improved psychiatric symptoms in patients with bipolar disorder and schizophrenia. Participants reported better mood, energy, and sleep, while metabolic markers (such as insulin resistance) also improved. 

• A 2025 review in Psychiatry Research highlighted that ketogenic diets reduce brain inflammation, balance neurotransmitters (like GABA and glutamate), and enhance mitochondrial function—key factors in mood disorders. 

• Case studies have shown remission of psychotic symptoms in schizophrenia patients after adopting a ketogenic diet, suggesting it may be a viable adjunct therapy. 

How Does a Ketogenic Diet Help? 

• Stabilises Neurons: By providing ketones (instead of glucose) as fuel, the brain experiences less excitability, which can help with conditions like epilepsy, bipolar disorder, and anxiety. 

• Reduces Oxidative Stress: Ketones act as antioxidants, protecting brain cells from damage. 

• Improves Metabolic Health: Many mental health disorders are linked to insulin resistance and metabolic dysfunction, which keto diets can address. 

While more large-scale trials are needed, ketogenic diets show strong potential for managing mood disorders, especially in individuals with metabolic issues. 

Supplements That Support Mental Wellbeing 

Beyond diet, certain supplements can enhance brain function and mood. 

Key Supplements for Mental Health: 

• Omega-3 Fatty Acids (EPA/DHA): Reduce inflammation and support neurotransmitter function; linked to lower depression and anxiety risk. 

• Magnesium: Deficiency is common in anxiety and depression; helps regulate GABA (a calming neurotransmitter). 

• Vitamin D: Low levels are associated with seasonal affective disorder (SAD) and depression. 

• Probiotics: Improve gut health, which is crucial for serotonin production. 

• B Vitamins (Especially B12 & Folate): Support energy metabolism and neurotransmitter synthesis. 

While supplements can help, they work best alongside a nutrient-dense, low-sugar diet. 

What Can You Do? 

✔ Cut back on added sugars (aim for <25g/day). 

✔ Consider a low-carb or ketogenic diet if struggling with mood disorders. 

✔ Support brain health with omega-3s, magnesium, and probiotics. 

✔ Stay updated on metabolic psychiatry research—this field is rapidly evolving! 

Conclusion 

Food is medicine for the mind; what we eat directly affects how we feel. Reducing sugar, experimenting with low-carb or ketogenic diets, and incorporating key supplements can be powerful tools for mental wellbeing. 

Oliver Smith

Hypnotherapy, Nutritionist

• Diploma of Clinical Hypnotherapy(Australian Academy of Hypnosis)
• Registered Associate of Australian Hypnosis Alliance
• Professional Cognitive Behavioral Therapy (CBT) Diploma
• Cognitive Behavioral Therapy (CBT) for Food Disorders
• Post Grad Module of Psychobiology & Neuroscience (University of Essex - UK)
• Post Grad Diploma in Clinical Nutrition
• Professional Training in Ketogenic Diet Nutrition & Treatment(Nutrition Network)
• Diabetes Reversal Training (Nutrition Network)

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References

• The Ferr (2024). Sugars and brain inflammation. [Online] Available at: https://www.frontiersin.org/journals/molecular-neuroscience/articles/10.3389/fnmol.2021.732120/full [Accessed 27 April 2024]. 

•  Stanford News (2025). Keto diet therapy for mental illness: new research. [Online] Available at: https://news.stanford.edu/stories/2025/04/keto-diet-therapy-mental-illness-research [Accessed 27 April 2024]. 
• Frontiers in Molecular Neuroscience (2021). [Online] Available at:https://www.frontiersin.org/journals/molecular-neuroscience/articles/10.3389/fnmol.2021.732120/full [Accessed 27 April 2024].
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• HealthMatch (2024). Vitamin D for seasonal depression. [Online] Available at:
  https://healthmatch.io/seasonal-affective-disorder/vitamin-d-for-seasonal-depression [Accessed 27 April 2024]. 
• SpringerLink (2023). [Online] Available at: https://link.springer.com/article/10.1007/s00210-023-02762-5 [Accessed 27 April 2024].
• MDPI (2023). Nutrients, 15(11), p.2525. [Online] Available at: https://www.mdpi.com/2072-6643/15/11/2525 [Accessed 27 April 2024].