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What if I told you there was a medical treatment that could improve your memory, prevent dreaded diseases like Alzheimer’s and Parkinson’s disease AND lose weight? And what if I also told you it wouldn’t cost you a penny?

I’m sure you wouldn’t believe me but don’t take my word for it. Check out the science below that backs up these statements.

Time-Restricted Eating (TRE) – aka Intermittent Fasting

The treatment, Time Restricted Eating, is a form of intermittent fasting that has profound benefits for everyone.

On my podcast, The Smartest Doctor in the Room, I interviewed Dr. Mark Mattson, the former Chief of Laboratory Neuroscience at the National Institute of Aging and a Professor of Neuroscience at Johns Hopkins University School of Medicine about the benefits of time-restricted eating (TRE) on brain health and aging. Dr. Mattson and I discussed the overall key findings from his expansive publications (450 articles) on longevity and brain health.

What Is Time-Restricted Eating or Intermittent Fasting?

It is really quite simple: you limit your food intake to only certain hours of the time. Intermittent fasting (IF) is a term used to describe a variety of eating patterns in which no or few calories are consumed for time periods that can range from 12 hours to several days on a recurring basis. Historically, fasting has been used as both a religious and medical practice for thousands of years. In fact, fasting for medical purposes has been suggested since the time of ancient Chinese, Greek, and Roman physicians.

On the podcast, we focused on the 16/8 time-restricted eating which is where you limit the hours you eat to an 8-hour window and fast for the remaining 16 hours of the day.

According to Dr. Mattson, by keeping your food intake to this 8-hour window, you allow your body chemistry to do 2 important things:

  1. you switch your metabolism from glucose to ketones
  2. your immune system is better able to clean up the debris from cells

Glucose is the main source of energy but in times of fasting, the body switches to ketones. Ketones limit the insulin response in the body and this has a positive effect on cells that slows down the aging process.

Autophagy is the term for cleaning up cellular debris; this is also what happens when you eat only in an 8 hour period. The basic idea behind autophagy is that in the absence of external sources of food, the body begins to eat itself, destroying and recycling its own damaged cell bits and proteins so that new ones can be built.

How to Time Restrict Your Eating (Example)

For 16/8 time-restricted eating, you fast for 16 hours and only eat within an 8-hour window. For example, if you have your last meal completed by 8 pm and don’t eat after that before bed. Then you sleep for 8 hours. Your next meal would be at 12 pm the following day. You can have a coffee or tea without sugar in the morning but no food. Most people prefer to eat between 11 am and 7 pm or 12 pm and 8 pm on this fasting plan.

Effects of Hormesis and Fasting

Dr. Mattson’s work has studied the effects of hormesis on the body. Hormesis is when you essentially challenge the body with low-level stress whether in the form of fasting, exercise or eating plant-based foods (yes, I did say plant-based foods). Hormesis definition:

Hormesis is defined as any circumstance in which exposure of a cell or organism to a low dose of a substance or condition results in an adaptive stimulatory/beneficial outcome, while exposure to a high dose results in an inhibitory/detrimental outcome.

Apparently, the fruits and vegetables we believed to contain all those healthy antioxidants are actually healthy because they contain natural pesticides that stimulate our immune system. People who regularly consume vegetables, fruits and other plant products tend to have healthier brains and to be less likely to suffer from neurodegenerative diseases. In the past, we assumed this was mostly due to nutrients in the fruits and vegetables. Now we know there is more to it. In Dr. Mattson’s article What Doesn’t Kill You he states,

Bitter-tasting chemicals made by plants act as natural pesticides. When we eat plant-based foods, we consume low levels of these toxins, which mildly stress cells in the body in much the same way that exercise or going without food for long periods does. The cells do not die—in fact, they get stronger because their response to the stress shores up their ability to adapt to still more stress. This process of bolstering cellular resilience is called hormesis—and a growing body of research indicates that it accounts for the health benefits of consuming fruits and vegetables. Understanding hormesis’s effects may even provide new ways to prevent or treat some of the most devastating brain diseases, including Alzheimer’s, Parkinson’s and stroke.

Interestingly, low-level exercise also stresses the body in a good way whereas intense exercise can actually lower immunity unless you allow for a significant rest and recovery period.

Another fascinating concept is that low-level toxins can also stress the body in a good way but high levels of mercury or selenium are detrimental to the immune system.

Fasting, which has been done since early man searched for food or done since biblical times on holy days, has been found to also stress the body in a positive way. Fasting for 16 hours or 24 hours allows the body to maintain low insulin levels and clean out toxins.

From an evolutionary standpoint, the demonstration that fasting intermittently can be beneficial should not be overly surprising as it creates mild stress that puts the brain into a state where the protection of neurons is paramount.

Fasting and Brain Health Studies

Researchers like Dr. Mattson have shown in mice that diseases like Alzheimer’s and Parkinson’s can be prevented when the different forms of hormesis are implemented through fasting.

Clinicians such as Dr. Dale Bredeson at UCLA School of Medicine have put together a program, that is based on scientific evidence, which helps reverse Alzheimer’s disease. Dr. Bredesen reveals that Alzheimer’s disease is not one condition but rather three distinct conditions and his protocol outlines 36 metabolic factors that can trigger “downsizing” in the brain. And part of his protocol is using aspects of hormesis.

Dr. Bredeson’s core recommendations are:

  1. Get 8 hours of sleep
  2. Fast at least 12 hours – no eating after 7 pm
  3. Do yoga and meditation to reduce stress
  4. Do aerobic exercise 30-60 minutes five times a week
  5. Do weight-bearing exercises 3 times a week
  6. Eat a plant-based diet packed with broccoli, cauliflower, seeds, and nuts
  7. Avoid high mercury fish such as tuna and swordfish
  8. Drink lots of water
  9. Eliminate gluten and sugar such as the ones in cakes and pastries
Fasting and Weight Loss

The Circadian Code

Wouldn’t it be great to lose weight and not starve yourself? What if eating just about the same amount of calories but in a time-restricted period allowed you to not gain weight but actually lose weight.

This is the scientific research that Dr. Satchin Panda, Ph.D. from the Salk Institute in California has published in her book The Circadian Code: Lose Weight, Supercharge Your Energy, and Transform Your Health from Morning to Midnight.

The Circadian Code outlines lifestyle changes to help your circadian clock back on track. His plan teaches you how to enhance weight loss, improve sleep, optimize exercise and manage technology so it doesn’t interfere with the body’s natural rhythm. Dr. Panda’s life-changing methods show you how to prevent and reverse ailments like diabetes, cancer, and dementia, as well as microbiome conditions like acid reflux, heartburn, and irritable bowel disease.

Of course, Dr. Panda recommends eating healthy foods to aid in weight loss. This means sticking to fresh produce, lean meats and cutting out excessive carbohydrates and sugars. He also advocates for a healthy lifestyle with 8 hours of sleep and regular exercise. Overall, his recommendations are very similar to the protocol used by Dr. Bredeson.


True or false quiz based on what you learned about intermittent fasting.

  1. “Eat breakfast like a king, lunch like a prince, dinner like a pauper?”
    False – with TRE skipping breakfast may be easier and more convenient.
  2. “Hari Hachi bun m” – Japanese for eating until you are 80% full?
    True – eating until you are 80% full is a good idea. Don’t stuff yourself and stress your digestive system. Japan’s island Okinawa is considered a Blue Zone because they have the highest amount of healthy centenarians.
  3. Fasting or starving yourself is the only way to lose weight?
    False – with TRE you can eat the same amount of calories but only in an 8-hour window.
About the Author – Dr. Dean Mitchell, M.D.

Dr. Dean Mitchell, M.D.

Dr. Dean Mitchell, M.D. is a Board Certified Allergist and Immunologist based out of NYC. He graduated from the Sackler School of Medicine and completed training at the Robert Cooke Allergy Institute in New York City. He is also a Clinical Assistant Professor at Touro College of Osteopathic Medicine, a fellow of the American Academy of Allergy, Asthma, and Immunology, and the author of Dr. Dean Mitchell’s Allergy and Asthma Solution: The Ultimate Program for Reversing Your Symptoms One Drop at a Time. Dr. Dean Mitchell, M.D. has also been featured in The New York Times, The Huffington Post, Fitness Magazine, Dr. Oz and News NY 1. Dr. Mitchell also hosts the podcast The Smartest Doctor in the Room – a combination of a lively, personal and in-depth interview with top healthcare specialists.


Anton, Stephen & Moehl, Keelin & Donahoo, William & Marosi, Krisztina & Lee, Stephanie & Mainous, Arch & Leeuwenburgh, Christiaan & P. Mattson, Mark. (2017). Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting: Flipping the Metabolic Switch. Obesity. 26. 10.1002/oby.22065.

Zimmerman, Edit. What is Autophagy? The Cut, April 25, 2019.

Mattson, Mark P., Calabrese, Edward J. Hormesis: A Revolution in Biology, Toxicology, and Medicine. 2010.

Mattson, Mark P. What Doesn’t Kill You., July 2015.

Panda, Ph.D., Satchin. The Circadian Code: Lose Weight, Supercharge Your Energy, and Transform Your Health from Morning to Midnight. Penguin Random House, 2018.