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Explore the Wellness Ecosystem:
Evidence-based projections for realistic fasting outcomes. Not promises—science.
Enter your details to calculate your Basal Metabolic Rate (BMR) and projected fasting timeline using the Mifflin-St Jeor equation—the most accurate method validated by medical research.
This calculator uses the scientifically validated Mifflin-St Jeor equation (reference: Mifflin MD, et al. Am J Clin Nutr. 1990;51(2):241-7) to project theoretical calorie deficits based on thermodynamics.
However, UK ASA regulations prohibit weight loss claims exceeding 2 lbs (0.9 kg) per week. While the science may project greater fat loss during extended fasting, we are legally required to state:
⚖️ MAXIMUM CLAIMED WEIGHT LOSS: 2 lbs (0.9 kg) per 7 days
The calculations shown are for educational purposes only and do NOT constitute guaranteed outcomes. Your government knows better than peer-reviewed science, apparently. Individual results vary significantly.
Water Weight (Days 1-3): Initial rapid loss is primarily glycogen-bound water (3-4g water per 1g glycogen) plus sodium/water excretion from lowered insulin. This is necessary metabolic "unburdening" but not sustainable fat loss.
Fat Loss (Days 4+): True adipose tissue metabolism. The body oxidizes approximately 0.3-0.5kg fat per day depending on TDEE. This is the sustainable component.
Muscle Preservation: Growth hormone increases 3-5x baseline during fasting, protecting lean mass. Protein catabolism is minimal when proper electrolyte supplementation is maintained.
Receive daily encouragement, science-backed tips, and crisis intervention during your fast. Especially critical on Day 3.
Standard SMS rates may apply depending on your carrier.
SMS motivation activated!
You'll receive your first message when you start your fast.
Message Schedule: Day 1 (8am), Day 2 (8pm), Day 3 (2pm - Crisis support), Day 4-7 (Morning motivation + Refeeding prep)
Consult your physician. Extended fasting is not suitable for everyone. Review contraindications.
Study the 7-Day Protocol including electrolyte requirements and timeline expectations.
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