Understanding what makes for a healthy diet and lifestyle has never been more important. Shockingly, obesity has now become a greater global health crisis than hunger, and is the leading cause of disability and chronic illness around the world.1,2 On average, the global population is plagued by obesity-related pain and illness during the last 14 years of life, which takes a significant toll on quality of life.3
One lifestyle factor that appears to be driving not only obesity but also many chronic disease processes is the fact that we rarely avoid eating for more than 12 hours. In fact, Dr. Satchin Panda's research shows that 90 percent of us eat across more than 12 hours a day.
Historically, generous amounts of food were not accessible throughout the entire year, let alone 24/7, and evidence strongly shows your body simply isn't designed to run optimally when continuously fed and will radically increase your risk for chronic degenerative disease when you regularly violate this principle.
If you eat throughout the day and never skip a meal, your body adapts to burning sugar as its primary fuel, which down-regulates enzymes that utilize and burn your stored fat. If you struggle to lose weight, this may well be a significant part of the problem — your body has simply lost the metabolic flexibility to burn fat for fuel.
Moreover, research has confirmed that many biological repair and rejuvenation processes take place in the absence of food, and this is another reason why all-day grazing triggers disease. In a nutshell, your body was designed to a) run on fat as its primary fuel, and b) cycle through periods of feast and famine.
Fasting May Be a Key Intervention to Improve Health and Longevity
Fasting — where you abstain from food either for a large part of each day, or a few days each week or month — is one of the oldest dietary interventions in the world, and modern science confirms it can indeed have a profoundly beneficial influence on your health and longevity.
The paper4 "A Time to Fast," published in the November 2018 issue of Science, reviews many of these health benefits, noting that:
"Adjustment of meal size and frequency have emerged as powerful tools to ameliorate and postpone the onset of disease and delay aging, whereas periods of fasting, with or without energy intake, can have profound health benefits.
The underlying physiological processes involve periodic shifts of metabolic fuel sources, promotion of repair mechanisms, and the optimization of energy utilization for cellular and organismal health.
Future research endeavors should be directed to the integration of a balanced nutritious diet with controlled meal size and patterns and periods of fasting to develop better strategies to prevent, postpone and treat the socioeconomical burden of chronic diseases associated with aging …
In general, both prolonged reduction in daily caloric intake and periodic fasting cycles have the power to delay the onset of disease and increase longevity."
How Fasting Benefits Health
While there are many different types of fasting, the key component is the cycling of feeding and fasting. By mimicking the eating habits of our ancestors, you restore your body to a more natural state that allows a whole host of biochemical benefits to occur.5,6,7,8
Indeed, intermittent fasting is one of the most effective interventions I've found to reverse insulin resistance, shed excess weight and improve body composition, decrease your risk for heart disease and cancer, protect cognitive function and increase longevity.10 Two core mechanisms responsible for these benefits are:
1. Improved insulin and leptin sensitivity, and improved circulating glucose and lipid levels
2. Triggering your body to more effectively burn fat for fuel, which encourages your liver to create water-soluble fats called ketones that:
• Burn far more efficiently than carbs, thereby creating fewer reactive oxygen species and secondary free radicals that can damage your cellular and mitochondrial cell membranes, proteins and DNA
• Decrease inflammation, as ketones are histone deacetylase (HDAC) inhibitors that radically reduce inflammatory molecules
• Mimic the life span-extending properties of calorie restriction, which includes improved glucose metabolism and reduced inflammation11
• Have a similar structure to branched-chain amino acids, thereby aiding the building of muscle mass and promoting longevity12
Ketone metabolism also increases the negative redox potential of your family of NAD coenzyme redox molecules, which helps control oxidative damage by increasing NADPH and promoting transcription of enzymes of the antioxidant pathways though activation of FOXO3a.13
In a nutshell, ketone metabolism effectively reduces oxidative damage, which translates into improved health and longevity. Both calorie restriction and intermittent fasting also inhibit the mTOR pathway, which has been shown to play an important role in life extension. Note that ketone metabolism, not ketone supplements, has been shown to produce these benefits.