What we eat has a direct impact on our well-being (both mental and physical).  The modern dietary changes that include junk food, processed food and fast food have led to many serious health concerns such as diabetes, obesity, heart disease, and an array of mental health disorders, including depression, schizophrenia, and anxiety (Source: The Guardian).
Whole Foods Diet / Paleo Diet
There is no fixed definition of a whole foods/plant-based diet (WFPB diet) – also known as a Paleo diet. But the Paleo/WFPB diet is a dietary routine based on the foods humans probably ate in the Paleothilic era. It comprises vegetables, lean meats, seeds, nuts, and other whole foods, including legumes, grains, and dairy products.
Basics of a Whole Food Diet
The basic principles of a Paleo or whole foods diet are:
- Avoiding processed foods
- Avoiding animal products except for lean meat
- Focusing on plant-based including fruits, vegetables, legumes, whole grains, seeds, and nuts
- Removing refined foods such as white flower process sugar and oils
- Paying attention to food quality, i.e., eating fresh, locally sourced organic food
Health Benefits of Paleo/WFPB Diet
- Weight Loss
Making dietary changes and eating clean has the most significant impact on weight management. Those struggling with weight loss see dramatic improvement after adopting a Paleo diet.
A meta-analysis of 12 studies showed that subjects assigned to Paleo lost more weight than those assigned to non-plant-based diets.
Another study of 65 obese adults revealed that participants assigned to the WFPB diet lost significantly more weight than the control group. They were also able to sustain the weight loss of 4.2 kgs after a one-year follow-up.
Weight gain and obesity are directly linked to a myriad of health risks (Source: NCBI). Thus, by maintaining a healthy weight Paleo/WFPB also benefit the body in many other ways, such as:
- Improves Cardiac Health
A mega study of over 200,000 people found that participants following a healthy plant-based diet have a significantly lower risk of heart disease than the group following a non-plant-based diet (Source: Healthline).
- Prevents Cognitive Decline
Various studies show the impact of a healthy diet on the brain. A plant-based diet is rich in nutrients, leading to a healthy brain function. Studies also show that people who eat healthily have a lower risk of cognitive decline. (Source: NCBI)
According to a review of nine studies, people that consumed more fruits and vegetables had a 20% lower risk of developing cognitive impairment such as dementia, Alzheimer’s disease, Parkinson’s disease, etc.
- Low Risk of Diabetes
People with poor dietary choices have a high risk of developing diabetes.
A study found that a plant-based diet is associated with failure 50% reduction in the risk of developing type 2 diabetes compared to a regular diet.
- Reduces Mental Health Disorders
Recently many studies have been conducted to explore the gut and mind connection. These studies investigate how what we eat has an impact on our moods and cognitive performance. (Source: Harvard Health)
Research shows that people with an unhealthy diet and lifestyle have a much higher risk of developing mental health disorders such as depression and anxiety.
Paleo/WFPB Diet and Depression
There is a large amount of scientific evidence about the positive effects of a healthy diet on mental health.
The results of a meta-analysis of randomized controlled trials published in the journal of Psychosomatic Medicine revealed that dietary interventions could reduce symptoms of depression. 
- Clinical Trial
A randomized controlled trial showed strong evidence that poor diet is linked to depression. This study examined that brief diet intervention improves depression and significantly reduces depressive symptoms. 
A randomized controlled trial of dietary improvement for adults with major depression published in BMC Medicine found that dietary improvement can treat depression. The results showed that dietary improvement is an efficacious and accessible treatment for highly prevalent mental disorders.
The Whole Foods Diet: The Lifesaving Plan for Health and Longevity by John Mackey, Alona Pulde MD, Matthew Lederman MD 
By default, Paleo is a diet rich in plant-based foods – thus, nutrient-rich, anti-inflammatory, and blood sugar regulation . So, it affects all the brain health units in our body.
Here are the key ways through which Paleo/WFPB diet leads to better mental health:
The Gut-Brain Connection
The brain is an energy-hungry organ, and what we eat has a massive impact on how it functions. Diet indirectly affects brain health through gut health information and blood sugar control.
Thus, a diet rich in processed and fast foods leads to severe consequences due to the high content of processed sugar and gluten – both when consumed in high amounts disturb the blood sugar and cause inflammation in the gut.  Moreover, this also leads to gut disorders that cause mental health disorders.
According to research, half of all patients with IBS (irritable bowel syndrome) suffer from mood disorders such as depression. (Source: WebMD)
A recent discovery of the gut microbiome has shaken the medical world. The gut microbiome is a community of healthy gut bacteria that has a direct numerological impact. The gut biome regulates mood and cognitive function (Source: NCBI).
Study shows that eating a diet rich in plants creates a healthy microbiome – leading to better mental health. Moreover, a disturbed microbiome is also directly linked to psychiatric disorders and the risk of major depression. [8,9]
To conclude, eating a clean diet rich in plant-based foods will result in a healthy and happy lifestyle. All those suffering from serious health concerns or experiencing depression symptoms are recommended to adopt a whole foods plant-based/Paleo diet.
- Nutritional Therapies For Mental Disorders by Shaheen E Lakhan and Karen F Vieira. 2008. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2248201/
- The Effects of Dietary Improvement on Symptoms of Depression and Anxiety: A Meta-Analysis of Randomized Controlled Trials by Joseph Firth, Wolfgang Marx, Sarah Dash, Rebekah Carney, Scott B. Teasdale, Marco Solmi, Brendon Stubbs, Felipe B. Schuch, André F. Carvalho, Felice Jacka, and Jerome Sarris. 2019. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6455094/
- A brief diet intervention can reduce symptoms of depression in young adults – A randomized controlled trial by Heather M. Francis. 2019 Retrieved from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0222768
- Dietary Effects on Microbiota—New Trends with Gluten-Free or Paleo Diet by Yurdagül Zopf, Dejan Reljic and Walburga Dieterich. 2018. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6313618/
- The gut microbiota and psychiatric illness by Glenda MacQueen, Michael Surette and Paul Moayyedi. 2017. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5373703/
- Making Sense of … the Microbiome in Psychiatry by Thomaz F S Bastiaanssen, Caitlin S M Cowan, Marcus J Claesson, Timothy G Dinan and John F Cryan. 2019. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6313131/
- Fast food fever: reviewing the impacts of the Western diet on immunity by Ian A Myles. 2017. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4074336/
- Discovery of novel community-relevant small proteins in a simplified human intestinal microbiome by Hannes Petruschke and colleagues. 2021. Retrieved from: https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-020-00981-z
- Whole foods diet https://www.verywellfit.com/what-is-a-whole-foods-diet-2241974
- The Whole Foods Diet: https://www.webmd.com/food-recipes/features/the-whole-foods-diet
- Six Reasons to Go Paleo for Mental Health: https://www.psychologytoday.com/us/blog/diagnosis-diet/201909/six-reasons-go-Paleo-mental-health
- Can the Paleo Diet Improve Your Mental Health?: https://www.neurologysantamonica.com/can-the-Paleo-diet-improve-your-mental-health/
- Food for Thought: Can the Paleo Diet Heal Mental Disorders?: https://health.usnews.com/health-news/articles/2014/01/31/food-for-thought-can-the-Paleo-diet-heal-mental-disorders
- Paleo and grain free diets: anxiety and depression success stories: https://www.everywomanover29.com/blog/Paleo-grain-free-anxiety-depression/
- HOW AN ANTI-INFLAMMATORY Paleo DIET CAN HELP WITH MENTAL ILLNESS: https://www.Paleo-britain.co.uk/how-an-anti-inflammatory-Paleo-diet-can-help-with-mental-illness/
- The Best Diet for Depression and Anxiety: https://www.hollyfisherhiggins.com/best-diet-depression-anxiety/