Intermittent Fasting: A Key Strategy to Optimize Metabolic Health and Longevity
by Dr. Laura Korman, DC
Here we are again, at the time of year when many people are highly motivated to take off those extra “holiday pounds.” When asked about my recommendation for the best strategy to lose that excess weight, my quick answer is to follow the ancestral practice of intermittent fasting. Most of us are familiar with fasting as it applies to prayer or for religious reasons, but many are not aware of its many benefits related to metabolic health, anti-aging and disease prevention.
Intermittent fasting is an eating plan that alternates between consuming and abstaining from, or greatly reducing, the intake of calories for given periods of time. When we fast, our bodies begin to shift from burning glucose and glycogen (fuels needed for immediate energy needs) to burning body fat (fuel stored for future energy needs).
The key to remember is that we must burn through the glucose available in our bodies before we can “earn the right” to tap into our stored fat reserves. This metabolic shift from burning glucose to burning fat happens at different rates, depending on our age, activity level, the type of foods we consume and the percent of excess body fat we already have on board.
The food we eat is energy, and the body needs to either use it or store it. The problem is that, unlike our ancestors, people today are less active, and are continuously feeding, especially on carbohydrate rich foods. This combination provides more fuel than the body readily needs, thus excess energy must be stored as body fat. Taking longer intervals between feeding is an effective method to switch the body into a fat burning machine.
Fasting can be done in various ways, including daily time restricted feeding where a person eats within an eight-hour window, then fasts for the remaining 16 hours. Another way is called a 5:2 alternate day approach, where a person consumes a regular intake of calories five days a week, then consumes 500-600 calories on the other two days. Fasting can seen foreign or even seem cruel to modern humans, as we have been programmed in the last 50 years to believe that we should consume three meals and two or three snacks per day to prevent our blood sugar from dropping and keep our metabolisms stimulated.
While continuous feeding can be beneficial to a young active athlete, it is not optimal advice for most Americans. In fact, this notion of needing to frequently feed ourselves has played a contributing role in the steady rise of obesity and related chronic diseases during this same 50 year period of time.
We live in a much different world than our ancestors did. We are more sedentary, working indoors, spending more time on computers, social media and TV, and frequently eating late into the evening. Many of us also have more accessibility to food than in previous times, with grocery stores, convenient stores and drive through restaurants full of packaged, preserved, processed, and sugar laden foods or beverages.
These refined foods quickly raise blood glucose levels and, subsequently, insulin levels. This signals the body to store more fat than the unprocessed foods commonly consumed 100 years ago. Frequent consumption of these “convenience” foods keep us in a constantly fed state, storing fat. The feast and famine cycling of our ancestors was always a normal way of life, and now we’re finding that, by mimicking this lifestyle, we can tap into some powerful health benefits for optimal metabolism, disease prevention and improved longevity.
Intermittent fasting is shown to not only to lower risk for obesity and diabetes, but according to the New England Journal of Medicine, it is also shown to improve multiple risk factors for heart disease including blood pressure, resting heart rate, lipids and insulin resistance. Strong pre-clinical studies show that neurodegenerative disorders including Alzheimer’s and Parkinsons can be slowed or delayed with fasting strategies by reducing neuroinflammation and boosting mitochondrial (the powerhouse of our cells) function.
Fasting is also shown to improve cognition, memory and recall in adults. In addition, fasting stimulates autophagy where the body cleanses itself from damaged and precancerous cells. It improves antioxidant function, DNA repair and lowers chronic systemic inflammatory responses. In athletes, strategic fasting not only lowers body fat composition, but also improves endurance and maintains muscle mass with weight training.
While intermittent fasting is considered safe for the majority of people, it should be avoided in those who are severely malnourished or underweight, children under 18 years of age, and pregnant or breastfeeding women. Caution or professional guidance should be taken with people taking medications, or have type-1 or -2 diabetes.
I have found intermittent fasting to be a beneficial switch when it comes to breaking through weight loss plateaus for my patients, and I highly recommend it during my various nutritional programs. I will be holding a free five-pound challenge in January 2022 for those interested in ensuring their weight is back on track after the holidays.
For more information about this challenge or how to make intermittent fasting part of your lifestyle, please call my office at 941-629-6700 or visit DrLauraKorman.com.