The claimWhat Dana actually said
White posted a video describing an 86-hour water fast he completed, saying he felt incredible and walking viewers through how he did it, including electrolytes and bone broth on the way out. He explicitly noted he is not a doctor and attributed the disease-risk claims to experts he had consulted.
- bjjee.com: Dana White in their own words
- de Cabo R and Mattson MP, New England Journal of Medicine, 2019: review concluding that much of the evidence linking intermittent fasting to disease prevention comes from animal studies rather than human outcome trials.
- Trepanowski JF et al., JAMA Internal Medicine, 2017: alternate-day fasting produced no greater weight loss, maintenance or cardioprotective benefit than daily calorie restriction over one year.
- Lowe DA et al., JAMA Internal Medicine, 2020: the TREAT randomized trial found time-restricted eating produced only modest weight loss, with a substantial proportion from lean mass.
Why it mattersWhy this matters for longevity
Prolonged water-only fasting carries real risks including electrolyte disturbance, dehydration and refeeding problems, and it interacts with common medications
Animal lifespan and disease findings have repeatedly failed to reproduce in humans
Feeling good during a fast is not evidence about disease risk decades later
The evidenceWhat the science says
The best human evidence is about short-term metabolic outcomes. A randomized trial of alternate-day fasting found no greater weight loss, weight maintenance or cardioprotective benefit than daily calorie restriction over a year. A randomized trial of time-restricted eating found only modest weight loss, a meaningful share of which came from lean mass. A widely cited review summarising the field noted that much of the disease-prevention signal comes from animal models.
What the evidence does not support is the specific claim. There is no randomized human trial, and no strong prospective cohort, showing that multi-day water-only fasting lowers cancer incidence or Alzheimer's risk. Extended fasting is also not a neutral act: it can cause electrolyte and blood pressure problems, is unsafe for people with diabetes, eating disorder history, or on several classes of medication, and carries refeeding risk on the way out.
TakeawayThe honest takeaway
The practical lesson
If you want the metabolic benefits people associate with fasting, the evidence points to overall calorie intake and diet quality rather than to going 86 hours without food.
RelatedRelated habits
Each of these is a habit you can build on its own. Explore them through the Topics index.
SupplementsThe supplement angle: Electrolytes
Support a habit, do not replace one
Sodium, potassium and magnesium are the usual concern during any extended fast, which is why fasting protocols include them. That is a way to reduce harm from the practice, not evidence that the practice delivers a health benefit.
Supplements can support good habits. They do not replace sleep, movement, nutrition, or medical care. Talk with your healthcare provider before starting anything new.
This is educational commentary, not medical advice, and does not imply that Dana White endorses, is affiliated with, or uses Winning Longevity or any product. We critique the claim and the evidence, not the person. Any direct quote is a placeholder until sourced. Talk with a qualified healthcare provider before changing your routine. See our health disclaimer.
