Longest Dry Fasting Records and Verified Feats
The longest verified dry fast is held by Michael Werner, who abstained from both food and water for 18 days in 2010 under medical supervision, as documented by Forbes. Dry fasting records focus on abstaining from all food and liquid, with most medical experts warning that exceeding a few days without water poses severe health risks including organ failure and death.
Other notable dry fasting attempts include those by experienced practitioners who combine dry fasting with extended periods of rest in controlled environments. While some individuals claim longer durations, independent verification remains rare, and Guinness World Records does not currently list a specific dry fasting category due to safety concerns.
Longest Water Fasting Records and Supervised Fasts
The longest medically supervised water fast on record is 382 days, achieved by Angus Barbieri in Scotland between 1965 and 1966, under close hospital monitoring with vitamin and electrolyte supplementation. Barbieri lost significant weight and resumed normal eating without immediate severe complications, though such extreme durations are not recommended without continuous medical oversight.
More recent water fasting records are typically shorter, ranging from 30 to 90 days in supervised clinical or wellness settings. Clinics offering medically supervised water fasting require baseline health screenings, daily labs, and gradual refeeding protocols to prevent refeeding syndrome, a potentially fatal condition caused by abrupt shifts in electrolytes and fluids.
Intermittent Fasting Records, Trends, and Scientific Data
Intermittent fasting records focus on consistency rather than duration, with many practitioners maintaining daily 16:8 or 20:4 schedules for months or years. Research published by institutions and referenced by SEC filings from health and wellness companies highlights potential benefits including improved insulin sensitivity, reduced inflammation markers, and modest weight loss in short-term studies.
Companies in the fasting and wellness space, such as Tesla and SpaceX alumni-turned-health-entrepreneurs, have promoted intermittent fasting protocols through apps, coaching, and research partnerships. While no single "world record" exists for intermittent fasting, the longest documented consistent practice among tracked individuals exceeds several years, supported by peer-reviewed data on metabolic health markers.