Metabolic Switching

Two Day-a-Week 18 Hour Fasting - A Simple Eating Regimen Solution, not a Diet. It is a new Lifestyle.

To all our patients: I created this page especially for you and we talked about Metabolic Switching during your Telehealth visit to keep you healthier. I have worked with you for many years, even decades for many, and together we successfully avoided having to suffer both a heart attack, stroke and sudden cardiac death. Metabolic Switching has added benefits to what we are already doing.

This year, we find ourselves in the midst of a once-in-a-century global pandemic, but if we are all in it together, we can end this before December 2021. We all need to follow the science and remain vigilant. There are every indications that a second wave is coming. If given the opportunity, this coronavirus has the potential to make every person on earth its host and a virus factory to infect others. Stay safe and follow all the recommended safety measures as I do.

Metabolic switching is not a diet and even in the unlikely event that you do not lose weight, you still benefit from it. 

It is changing the timing of when you eat for at least two days a week. This change in timing allows your body to switch fuel from using carbs (glucose) for 12 hours followed by 6 hours when it uses fatty acids from the breakdown of fat. This periodic flipping of the metabolic switch creates a lasting adaptive response that has many health benefits independent of weight loss.

Metabolic Switching

Because it was published in the most prestigious and rigorous medical journal in the world and costs nothing to implement it except spending extra time to educate my patients or in this case, creating a webpage and directing my patients to it, I decided to integrate metabolic switching as a component (not a replacement) of my evidence-based medical therapy. The second thing I need to do is to adapt it myself because it is good for me and because my patients' next question is - "Doc, how do I actually do this?".

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Glucose and fatty acids are the two main sources energy for the cells. After meals, glucose is used for energy, and fat is stored in adipose (fatty) tissue as triglycerides. During periods of fasting (16 to 18 hours) triglycerides are broken down to fatty acids and glycerol. The liver then converts fatty acids into ketone bodies, which provide the major source of energy (fuel) for many organs especially the brain. 

Intermittent 5:2 fasting has many benefits that goes beyond weight loss and reduction of damaging free radicals. It improves glucose regulation, increases stress resistance, autophagy and suppresses inflammation.  

During fasting, there is a metabolic switch that occurs - from the use of glucose as the fuel source to the use of fatty acids and ketone bodies resulting in more efficient energy production and less oxidative stress. In addition to being use as fuel source, ketone bodies have other benefits: they are potent signaling molecules with major positive effects on cell and organ functions. Ketone bodies regulate the expression and activity of many proteins and molecules that are known to influence health and aging.

Intermittent fasting causes intermittent metabolic switching which over time results in lasting adaptive responses that leads to increased antioxidant defenses, DNA repair, protein quality control, mitochondrial biogenesis and down-regulation of inflammation. These responses enable cells to remove damage proteins and mitochondria and recycle undamaged molecules.

Intermittent fasting improves indicators of cardiovascular health: blood pressure, resting heart rate, LDL and HDL-cholesterol levels, triglycerides, glucose and insulin, insulin resistance and inflammation.

Other than the heart benefits, there are other benefits - one is preventing or delaying the onset of neurocognitive decline (dementia). It is especially important since there is no effective drug for it. 

Here is Dr. Ekberg giving a nice presentation about it. Ignore the attention-grabbing thumbnail - this is not for women who can wear a bikini.

Here is how I am trying to implement it for myself.

1. Choose the two or three non-consecutive days a week for the 18 hour fast. 

2. The night before, last food consumption is no later than 9:00 PM. That is the time the fasting starts. No restriction on water. 

3. The following day - filtered or bottled water, coffee, tea and other zero calories drink allowed until fasting is ended. 

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I need to drink during the 18 hour fast - may consume less than 50 calories without breaking the fast. I like a cold cup of Cusa Mango Green tea (zero calories) with a packet of Truvia natural sweetener and a hot cup of Kikkoman seaweed soup (15 calories).    

4. The exercise below is not part of Metabolic Switching. Make your own adjustments to fit your ability and level of fitness - slower pace, shorter duration and simplify the movements if you need to and if this is too much, don’t do it at all and let me know during your next visit. 

A thirty minute fast walking YouTube exercise with Leslie Sansone during the day. This is not part of the metabolic switching but something I already do daily and it can help deplete glucose storage (glycogen) sooner and initiate switching earlier to stored fat (fatty acids and ketone bodies) as energy source.

5. Feeding ends the fast between 6:00 PM and 9:00 PM with a healthy dinner (500 to 700 calories).

My choices: A healthy frozen dinner plus a dessert, like below,

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A take-out dinner - Teriyaki Beef Bento Box (Ichiban Sushi), Salmon or Steak Kabob (Zoe’s Kitchen) with soup and small salad.

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Salmon Kabob (above)     Steak Kabob (below)

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Canned wild caught sardines in extra virgin olive oil (King Oscar) with quinoa & brown rice with garlic.

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Panera Bread - Choose 2: Half sandwich and cup of soup

As you can tell, we don’t cook much - once a week, we’ll broil Chilean seabass or a thin cut of ribeye steak. If you enjoy cooking, it will probably be better and easier. 

It is not as difficult as I initially thought. It is doable as a permanent lifestyle change. There may be weeks that instead of 5:2, I will want to go 4:3 or later, even 2:1 on a short term basis.

What do I eat on the other days? This is not a diet - this is what I usually eat since the pandemic started.

1. The Okinawan rule: stop eating when 70% to 80% full.

2. No table sugar. No regular soda. Just tea, orange-flavored zero-calorie sparkling water and filtered tap water .

3. More good quality meat, fish, chicken.

4. More liberal on animal fat. More olive oil, less other vegetable oils. More Omega 3 (fish), less Omega 6 (plant-based). 

5. Less carbs. 

6. More nuts, vegetables and fruits.

7. A small nice dessert after dinner - I choose not to give this up - but reduce the portion.

8. Skip breakfast most of the time. Break the cultural habit of eating 3 square meals a day plus 2 snacks.

9. Even on non-fasting days, I eat less than before because I do not experience hunger and craving as much. 

My verdict after eight weeks: Changing the timing of eating is NOT hard, even the 4:3 and 2:1 schedule. The cold tea with Truvia and hot seaweed soup help while fasting. To my pleasant surprise, I am not really hungry during the 18 hour fast and I have more energy and better mental clarity - I expected just the opposite. I lost 5 lbs (5’5”, 138 lbs). My systolic blood pressure and blood glucose are 10 points lower. I am recommending this metabolic switching regimen to many of my patients. You don’t need to be overweight to try this. 

Please visit for Dr. deGoma’s message and instructions for you.

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