Perform the right type of fasting
Nutrition and fasting are intimately connected. Tapping into your body's nutrient-sensing networks through fasting, can unlock a wealth of benefits, from weight loss to improved insulin sensitivity, as well as biological age reversal.
In this article, we will explore the science behind fasting, and what you need to fast properly and safely. The trick is to find the sweet spot which does not cause unnecessary stress or worsen micronutrient deficiencies in your body. As with any powerful tool, optimality is seldom found at extremes.
‘’Diet can reprogram your body and put it on a path to live longer’’
-Dr. Valter Longo, longevity and fasting expert.
Fasting and HormesisFasting is a form of hormesis as it involves a temporary stressor or challenge to the body. When the body is deprived of nutrients and energy, several stress response pathways are activated, which can improve cellular health and longevity. Hormesis promotes adaptation and resilience, which can protect against the negative effects of chronic stress and ageing.
The Science Behind
1. Your Body’s Ageing Defence Pathways
Restricting protein and sugar intake through fasting have been shown to inhibit growth signalling pathways such as mTOR and IGF. Decreased mTOR and IGF signalling may promote longevity by reducing cellular damage and increasing cellular repair mechanisms. Fasting basically induces the activation of repair signalling pathways like AMPK and autophagy, essential to help prevent neurodegenerative diseases such as Alzheimer’s and Parkinsons or cancer. IF also stimulates the production of human growth hormone (HGH). Higher levels of HGH are associated with increased muscle mass, improved bone density, reduced body fat, and better insulin sensitivity.
2. The Promise of Sirtuins (SIRTs)
During fasting, the body undergoes metabolic changes that activate sirtuins. These include a decrease in blood glucose levels, an increased production of ketone bodies, and a reduction in insulin and IGF-1 levels. Sirtuins respond to these changes by promoting cellular processes that enhance cellular survival and repair, such as DNA repair, autophagy and mitochondrial biogenesis.
Studies have shown that sirtuin activation through fasting or caloric restriction can increase lifespan in yeast, flies and mice. In humans, studies suggest that IF or CR can improve healthspan and delay the onset of age-related diseases, such as type 2 diabetes, cancer, heart and brain diseases.
How to perform the right type of fasting
Intermittent Fasting (IF)
Intermittent fasting is an eating pattern that cycles between periods of eating and fasting. It usually includes a low or zero-calorie period, followed by a normal feeding period lasting between 12 and 48 hours. IF can be performed through:
- Complete water-only fasting
- Alternate-day fasting (ADF)
- 70% energy restriction every other day
- The 5:2 diet
- Time-restricted feeding (TRF), which restricts food intake to 6-12 hours per day
The Sweet Spot: 12 hours on, 12 hours off
Dr. Longo suggests that to benefit from fasting, it's essential to fast for the right duration. He suggests eating within a 12-hour window each day (for example from 8am — 8pm) and fast for the other 12 hours. Fasting longer than 12 hours may cause gallstones and reduce lifespan.
‘’So if you are fasting for 16 or more hours each day (e.g. following the 16/8 Intermittent Fasting method), you should reconsider your approach. When people fast too often, they seem to live shorter lives, " says Dr. Longo.
Skipping breakfast, a trend amongst intermittent fasters, might be problematic. ‘’People that skip breakfast may live shorter, but eating all day and snacking at night is also a problem. Those who eat for 15, 16 hours a day, also start developing health issues as they might be overweight, obese, and develop insulin resistance. 12 hours on, 12 hours off seems to be the sweet spot, with only positive results so far’’, he says.
Periodic Fasting (PF)
Periodic fasting refers to a severely calorie-restricted or water-only fasting period that lasts between 48 hours and one week, occurring at specific intervals or on an as-needed basis.
It should be performed less than once every two weeks, and usually for a limited number of times per year for not more than four days. PF can be achieved through water-only fasting or a fasting-mimicking diet (FMD), a plant-based diet that mimics the effects of water-only fasting on specific biomarkers.
The Sweet Spot: 3 days fast, every month or season
Assuming that you are in good health and have consulted with a healthcare professional, the best way to reap the benefits of PF is to fast every month or every new season for 3 days.
During this period, the body enters proper ketosis, induces strong autophagy, and reboots stem cells and the immune system. Proper ketosis is achieved after a minimum of 2-3 days of fasting, and ketones have various health benefits, such as reducing inflammation, improving brain health, and metabolism. After 3 days, various healthy and beneficial effects only spring into action, including stem cell maintenance and protection. Extended periods of fasting can be detrimental to health.
Intermittent fasting, periodic fasting and ageing-related diseases
Advancing age is the major risk factor for most major diseases, including cancer, diabetes and neurodegenerative, cardiovascular and immunological diseases. Because intermittent fasting, periodic fasting as well as fasting-mimicking diet cycles have been shown to slow down and partially reverse cellular ageing in rodent models, a number of studies investigated their potential application to the prevention and treatment of age-related diseases in humans. Incorporating a well-planned fasting regimen has been shown to have significant benefits to one's overall health and well-being, protecting against various age-related diseases.
Who should not perform fasting
Fasting is not suitable for everyone. Extended periods of fasting can even aggravate health by causing dehydration, electrolyte imbalances, hypoglycemia, malnutrition and muscle loss.Multiple scientific studies prove that fasting enhances healthspan and lifespan in males. It may have the opposite effect on females (physiological changes associated with the menstrual cycle affect the body’s response to external stimuli such as fasting).
As biology plays a huge part in shaping male and female metabolic responses, it might be optimal to stay away from intermittent fasting if you:
- are pregnant
- are chronically stressed
- do not usually sleep well
- are new to diet and exercise
- have a history of disordered eating
In other cases, you could still feel out how you react to IF by fasting at different times of your menstrual cycle. We recommend a milder approach, and to make sure you consult with your physician before jumping into any strict dieting plan.
Fasting mimetics - NMN Supplement
NMN might take home the ‘’supplement of year’’ trophy this year. It is a fasting-mimetic— a natural molecule that holds metabolic benefits similar to fasting by increasing NAD+ levels. NMN supplementation induces hormesis, thereby providing insulin sensitivity, increased fat burning, and protection against various chronic diseases.