Fasting Routines for Improved Immunity and Optimal Health
Jonas Bergqvist (SWE)
Physiotherapist, Functional Medicine Practitioner and CEO @ Paleo Institute, Sweden
Jonas teaches Paleo Lifestyle and Functional Medicine at Paleo Institute, where he is the creator of the training programs and course material. Jonas has published three books in Sweden and is a popular speaker in the fields of health and performance optimization. Jonas has also won the 200 meter race at the Swedish Championships for 35-40 year olds.
Jonas Bergquist, a functional medicine practitioner, explores fasting as a profound tool
Biohacking is finding tools to reach my potential, reach a solution for my life, and find out who I am. It's not about finding tools to withstand a stressed modern lifestyle; it's about going back to my origin and using technology to make it easier.
Summary
- Fasting serves as a powerful biohacking tool to optimize health by mimicking ancestral food scarcity, improving metabolic flexibility, and restoring natural biological rhythms. - Intermittent fasting routines like the 16:8 method or 24-hour cycles help lower blood sugar, improve lipid profiles, and reduce inflammation to combat common metabolic diseases. - Therapeutic fasting exceeding 48 hours promotes cellular repair, detoxification, and immune system calibration by breaking down damaged white blood cells and stimulating new growth. - Physical performance during fasting involves teaching the body to burn fatty acids more efficiently, though high-intensity efforts are limited by the lack of glycogen stores. - Fasting is not universal; it should be avoided by those with HPA axis dysfunction, eating disorders, or thyroid issues, and requires a pre-fast period without sugar, caffeine, or alcohol.
Article
Fasting As An Ancient Technology For A Modern Crisis
At Biohacker Summit 2017 Stockholm, Jonas Bergqvist Argued That Going Without Food Could Help Restore Metabolic Health, Reduce Inflammation, And Recalibrate The Immune System
In a conference devoted to performance, optimisation and the intelligent use of modern tools, one of the most arresting ideas at **Biohacker Summit 2017 Stockholm** was also one of the oldest. Speaking on **19 May 2017 in Stockholm, Sweden**, **Jonas Bergqvist** returned the room to a biological inheritance that predated apps, wearables and laboratory metrics by millennia: fasting.
His presentation, **“Fasting Routines for Improved Immunity and Optimal Health,”** framed food scarcity not as a threat alone, but as a condition human physiology had long been built to survive. The body, Bergqvist said, was designed for alternating periods of abundance and deprivation. Modern life, by contrast, had flattened that rhythm into a constant state of intake.
“**Fasting is very far from modern technology, but it is a remarkable tool for optimizing health,**” Bergqvist told the audience. “**It is not commercial and there are no products to sell, so it is very pure, very clean, and right in front of you.**”
A Biohacking Philosophy Rooted In Origins
Bergqvist, a Swedish physiotherapist, functional medicine practitioner and chief executive of the Paleo Institute, approached the subject not as a fad but as part of a broader philosophy. Biohacking, in his telling, was not chiefly about enduring a punishing modern lifestyle. It was about recovering something more original, then using selected technologies to support it.
That distinction mattered. In an age saturated with convenience, food had become permanently available, detached from season, effort and appetite. Refrigerators, supermarkets and social routines had replaced biological cues. For Bergqvist, fasting served as a way to reintroduce contrast into a system that had lost it.
“**Our whole body, our hormonal system, and our neurological system are designed for times when we have a lot of calories around us and times when they are scarce. That flexibility is our whole biology.**”
His argument rested on a familiar but urgent diagnosis: the modern West was being undone not by famine, but by metabolic excess. Blood sugar dysregulation, poor lipid profiles, rising inflammation and weight gain were no longer niche concerns. They had become the architecture of everyday disease.
The Case For Intermittent Fasting
Bergqvist drew a sharp line between fasting as a practical routine and fasting as therapy. For most people, he said, the gateway was intermittent fasting, especially protocols such as **16:8**, in which meals are consumed within an eight-hour window, or a **24-hour fast**, often structured from dinner to dinner.
These routines, he suggested, were relatively easy to fold into ordinary life and could produce meaningful effects without demanding total withdrawal from work, family or social obligations. The metabolic outcomes he described were striking: reduced blood glucose, lower long-term blood sugar markers, improved cholesterol patterns, lower blood pressure and decreased inflammation.
In this sense, fasting was presented not as deprivation for its own sake, but as an intervention against the dominant illnesses of abundance.
“**Fasting is a revolutionizing tool against metabolic and inflammatory diseases. We need to schedule fasting periods to make our ordinary lives as original as possible, just as our hunter-gatherer ancestors did.**”
There was, too, a more visible appeal. Bergqvist acknowledged fasting’s place in weight management, particularly for those trying to lose a small amount of body fat. Yet he resisted reducing it to aesthetics alone. The deeper aim was metabolic flexibility: teaching the body to move more easily between glucose and fat as fuel.
When Fasting Became Therapy
If intermittent fasting belonged to lifestyle design, **therapeutic fasting** occupied a different category altogether. Bergqvist defined it as fasting beyond **48 hours**, extending into periods of two to five days or longer. Here the body crossed into a more profound physiological shift.
As glycogen stores emptied, the body was forced to rely more heavily on fat oxidation. Bergqvist described this as a state in which mitochondria were effectively retrained to burn fatty acids with greater efficiency. But the more provocative claims concerned immunity and cellular repair.
“**Fasting has the potential to calibrate the immune system,**” he said. “**You put the cells in a repair mode where they can refresh their contents and build up their protection against inflammation and oxidative stress.**”
He pointed to research from the 1990s involving patients with arthritis, describing how fasting periods of five to ten days appeared to reduce symptoms during the fast itself. The mechanism, as he laid it out, involved the breakdown of certain white blood cells during energy scarcity, followed by a rebuilding process that might, in some inflammatory conditions, help “restart” an immune system that had become dysregulated.
This was not a claim of cure. Symptoms, he noted, often returned when eating resumed. But the suggestion was nonetheless powerful: that not eating could trigger a kind of biological housekeeping more profound than simple calorie restriction.
The Limits Of Performance In A Fasted State
Bergqvist did not romanticise the experience. Fasting, he cautioned, was highly individual. For some, it sharpened focus, reduced waist size and delivered a sense of mental clarity. For others, it brought fatigue, low mood and diminished physical capacity. Hormonal status, genetics and existing health conditions all shaped the outcome.
He was equally clear that fasting had limits in sport. Recounting his own three-day fast over Christmas, followed by a 10km run, Bergqvist described how the body could sustain lower-intensity endurance once it had fully shifted into fat-burning mode. But speed was another matter. Without glycogen, there was no reserve for high-intensity output.
The lesson was not that fasting made an athlete instantly better, but that it might, when used sparingly, help train the body to rely more effectively on fat at lower intensities. It was a tool, not a miracle.
A Warning Against Universal Prescriptions
One of the strongest notes in the talk was caution. Fasting, Bergqvist insisted, was **not for everyone**. Those with severe stress-related dysfunction, including HPA axis issues, certain thyroid conditions or eating disorders, should be wary. In some bodies, fasting might prove transformative. In others, it could be destabilising.
That insistence on context was one of the most compelling parts of the presentation. The culture around optimisation often leans toward universal solutions, toward rituals that promise mastery if followed with enough discipline. Bergqvist resisted that instinct. Before fasting, he advised, individuals should assess hormonal health and prepare carefully, including a period free from sugar, caffeine and alcohol.
He also emphasised environment. Long fasts, he suggested, were easier outside the home, away from social triggers and the sensory tyranny of food. Nature, movement, companionship, bone broth and salt were all offered as supports, not luxuries.
Health Beyond Diet Alone
For all the focus on fasting, Bergqvist repeatedly widened the frame. Health, he said, did not rest on one intervention. It emerged from a web of habits: nutrient-dense food, movement, sleep, recovery, purpose and social connection.
In one of the most memorable passages of the session, he turned to longevity, drawing from interviews with exceptionally old people. Their stories did not point to perfect diets or ideal exercise regimens. Instead, they returned to attitude and belonging.
“**The common recipe for a long and healthy life is having a positive way of looking at life and staying in a social context,**” Bergqvist said. “**People who live the longest socialize, they talk to others, and they are not alone.**”
It was a striking conclusion for a talk that began with abstinence. The body, Bergqvist suggested, may benefit from occasional emptiness. But a life cannot be built on restriction alone. It also requires community, meaning and the ordinary nourishment of other people.
An Old Discipline Reframed For A New Age
At **Biohacker Summit 2017 Stockholm**, Jonas Bergqvist presented fasting as both a biological reset and a cultural corrective. In a world that encouraged ceaseless consumption, he argued for rhythm. In a marketplace that monetised every insecurity, he offered a practice with no product attached. And in a health culture often obsessed with what to add, he made a case for the strategic power of taking something away.
The provocation of his talk lay partly in its simplicity. Fasting was not new. That was precisely the point. Its promise, as Bergqvist framed it, was that the human body had not forgotten the conditions in which it evolved, even if modern life had done its best to erase them.
Part of Biohacker Summit 2017 Stockholm