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Fasting -Benefit or Harm? My Professional Opinion…

Fasting -Benefit or Harm? My Professional Opinion…

Is this one of your burning questions since hearing all the “hype” about fasting? Are you concerned that this is just another fad? Are you confused about which type of fasting to do because you’ve heard it can be dangerous for you? Are you worried how you will feel when limiting your caloric intake while maintaining your busy life?

I hope to help alleviate any stress you may have about this issue and help you gain insight into fasting and why I feel it’s an imperative way of maintaining a healthy body weight while optimizing your longevity.

I have already written a short newsletter last year regarding fasting, but due to the fact that I continue to get questions about this subject and many people missed the letter, I have been drawn to revisit this critical topic.

It is generally accepted that we as humans have evolved from a “Feast and Famine” state resulting in a “thrifty genotype adaptation”. This theory can be applied to both hunter-gatherers, as well as agriculturalists. Today most humans in first world countries have access to food anytime, anywhere and will typically eat three meals per day, adding snacks and sugary desserts on top of an already heavy laden calorie day, and we sit and sit and sit. It is not surprising that we are faced with an obesity epidemic and that something must change for the health of our communities and the longevity of our species.

My goal as a clinician is to not only guide my patients into a healthier way of being, (research based) but to extend this into our broader communities where we collectively make an impact on our healthcare system and shift from “sick” care to healthy, preventative care so we can thrive in life, together!

The idea of calorie restriction is not new; however, it has gained incredible traction with the help of Dr. Valter Longo and his 30 years of research at the University of Southern California Longevity Institute. named by Time Magazine as one of the 50 Most Influential People in Health Care of 2018, Dr. Longo has likely changed the course of our health in the modern world, that is, as long as people will listen and implement the recommended changes.

What Dr. Longo has found when studying longevity, is that having a rest period from eating is critical both weight loss and for cellular repair and rejuvenation. When your body has time without eating, it then starts a process called gluconeogenesis. During gluconeogenesis, your liver converts non-carbohydrate materials like lactate, amino acids, and fats into glucose for fuel and therefore, you can burn your stored fat as fuel.

Hello weight loss or should I say goodbye fat!

I say “Yes to Fasting!”

Because insulin is produced in the morning, which is critical for regulating fat, carbohydrate and protein

metabolism, it is best to stop eating earlier in the evening and then ‘rest’ overnight and eat breakfast first thing in the morning. The advice you’ve been hearing for years “eat your breakfast as it’s the most important meal of your day” is still true and important to keep in mind when fasting.

Benefits of Fasting (especially with a prolonged fast)

  • Weight loss

  • Increases baseline metabolism

  • Improves insulin sensitivity

  • Improved HDL ‘good cholesterol’

  • Reduced Triglycerides

  • Reduces C-Reactive Protein (inflammatory marker in your body)

  • Improved Adiponectin (a protective protein hormone for regulating glucose)

  • Decreases inflammation

  • Reduces oxidative stress

  • Rids the body of excess fluid

  • Improves adaptive responses

  • Improves cognition

  • Decreases Neuro-degeneration

  • Reverses Auto-Immune Disease

  • Reverses Type 2 Diabetes

  • Improves thyroid hormone function and receptor sensitivity

  • Stimulates growth hormone which improves lean muscle and bone mass

Types of Fasting

Time Restricted Eating (TRE)

TRE limits your food intake to a certain number of hours in each day. By restricting the number of hours you eat you will consume less calories in a 24 hour (as long as you refrain from eating excessive portions when eating). For example, eat only between 7am to 6pm which results in a 13 hour fast. Dr. Longo prefers this type offasting(except when doing his FMD) noting his studies on centenarians in the world and their eating practices. This is the most common type of fast and is used for weight loss and improved metabolism and is considered safe.

Alternate Day Fasting (ADF)

ADF days you eat no caloric food or drinks on the fasting days

Alternate Day Partial Fasting or “Intermittent Fasting” (IF)

IF limits your food intake for a specific length of time on non-consecutive days per week. The most common pattern is a 16-24 hour fast without food. Typically, a 5:2 pattern is used where you have 5 days of normal healthy eating (don’t overeat) and 2 days of a fast (nonconsecutive days) such as Monday and Thursday. On fasting days, you should ideally restrict calories to about 500 for women and 600 for men in the non-fasting hours.

Periodic Short Term Fasting

Short term is fasting less than three consecutive days in a row.

Prolonged Fasting (PF) PF is an extended fast which would be 3 or more consecutive days of fasting. The main goal of this type of fast is to not only incur metabolic changes, but to also initiate stress on the body to stimulate innate changes that promote health and cellular rejuvenation.

A 5-day fast is more impactful than a 3 day fast and because a 5-day water fast can be challenging regarding compliance and comes with risks of gallstones and negative symptoms such as headaches, the National Institute for Health (NIH) funded a project to develop a fasting mimicking diet. The company L Nutra worked in collaboration with Dr. Valter Longo, because of his extensive research on fasting, to develop a cutting-edge program called The Fasting Mimicking Diet (FMD). The FMD is a 5 consecutive day medically designed prolonged fast (PF) that provides micro and macronutrients for the body yet at very low calories to keep the body in a “fasting mode”.

The FMD has one consume 750-1100 calories over the 5 days, which are plant based prepared foods. This is real food, not supplements or bizarre protein drinks so the body assimilates and digests the nutrients very well. And yes you coffee drinkers, you may have one cup of black coffee per day.

While all fasts will have an effect on metabolic function and weight loss, only the ProLon FMD repairs the body by cleaning cells and stimulating stem cells, while maintaining a small caloric load.

Day 1 the body starts to break down the fat reserve, which is good for fat loss.

Days 2 & 3 the process of Autophagy starts. Autophagy ‘self eating’ is when the cells literally eat themselves causing intracellular degradation. This process is our body’s way of cleaning house, which is important for cellular repair to fight inflammation.

Days 4 & 5 the body gets rid of the old damaged cells (waste proteins) and activates stem cells to replace them, which triggers cellular renewal and regeneration (FYI every organ has stem cells that are at a younger biological age).

Once you have completed the 5-day modified fast, you then have a transition day which should start with liquids and soups and then eat rice or gluten free pasta and small amounts of fish, lean meat and/or legumes and then you may go back to a healthy eating plan of your choice. I recommend choosing an eating plan that works for your body but keep up with a fasting method, such as the TRE to realize the continued health benefits.

It is recommended to do the FMD for 3 consecutive months and then once to twice per year. Dr. Longo does not recommend doing the FMD monthly unless you are obese or have not yet met physical goals based on laboratory data.

Dietary Eating Plans (these have been called ‘Diets’ but they should be labeled Eating Plans if you ask me). As a disclaimer here, I am not a trained nutritionist.

The Longevity ‘Diet’by Valter Longo is a pescatarian/ plant based diet with low carb and protein intake. It works to continue to reduce inflammation but the low carb doesn’t work if you want to gain lean mass. You need protein for your muscles to work.

Low Carbohydrate ‘Diet’most everyone should eat a low carb diet (unless you are a competitive athlete).

Paleolithic ‘Diet’a very good approach to eating but it’s not an ‘Atkin’ diet where you eat mostly meat, instead you need to consume a large amount of veggies. Beans are variable if they cause inflammation and so some people feel better on a lectin, legume free diet.

Ketogenic ‘Diet’- also a version of a low carb diet where you essentially limit carbs because they can turn to glucose and instead by eating high fat and moderate protein, your body will utilize Ketones for fuel. Our brain prefers Ketones for fuel, not glucose and it can cause inflammation. Therefore, this is a great way of eating if you have brain fog or any neurological inflammation. Again, you must eat veggies and not just cheese and meats.

*limited studies on the risks and benefits of this “diet” however clinical people report significant weight loss and improved brain cognition

Risks or Potential Downsides

  • Too much restriction you could become catabolic which could break down muscle and if extreme can damage the heart muscle (which is why the FMD includes some food and is not longer than 5 days at a time)

  • Not effective if people eat too many calories on non-fasting days

  • Poor compliance and hunger (I personally feel a mild to moderate hunger at various times of the day but find it tolerable)

  • May impact ability for more intense exercise while fasting

  • Caution if you have Hypoglycemia

  • Caution if you’ve had or currently have an eating disorder

  • Not recommended if under the age of 18

  • Not recommended if pregnant or nursing

  • Not recommended if allergic to nuts, soy, tomato or other ingredients in the meal plan

  • Not recommended if BMI <18.5

  • Can cause gas and if this happens start a probiotic 100 or 225 billion units by Orthomolecular

  • Due to the precision of engineering there is little waste so don't be concerned if you feel you are constipated - you can use Smooth Move Tea to help you eliminate

***The FMD mustbe prescribed by a Clinician and I can prescribe for existing patients only

Personally, I have been practicing intermittent fasting for over 2 years now and have completed 5 rounds of the ProLon FMD and next one is planned for the month of April.

I am at my goal weight and I feel amazing. When doing the FMD I have incredible mental focus and energy and only feel mild hunger that I feel is tolerable. I love the ease of this program and feel empowered at helping my body thrive!

However don’t take it from me, this is what one patient wanted to share with you about her experience with the FMD:


For the past two years, I have been a patient of Carrie's. She has helped me make so many positive changes to my life! In addition to integrative medical decisions, she has introduced me to the Prolon Fasting program. This easy to follow 5-day kit has really helped me gain momentum as I strive for a healthier lifestyle. The box comes with everything you need (except for the stove to cook the soups with). I am about to begin my eighth round and have been so pleased with how much better I feel after every box. I sleep better, have more energy and just in a better mood all around. My skin and hair are back to a more youthful state (I am 52 years old) and I have been able to keep off extra weight that I was puttingon before adding Prolon to my healthy changes. The program is 5 days at a time and since it is so easy to follow, I give it five shiny stars! Terri M

Interviews This is an excellent interview between Dr. Robert Roundtree, a local Boulder MD who is a leader in functional medicine with Dr. Valter Longo on Fasting and Longevity

My professional organization has a wonderful podcast from Dr. Joseph Antoun on why he has implemented the FMD into his business “L-Nutra” as well as his ideas on how this could revolutionize our healthcare system. I hope that all of you reading this will take the important information and implement fasting into your lifestyle to achieve optimal results in health and longevity ! Yours in health, Carrie Resources

Multiple articles regarding fasting, select the source that interests you:

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