Expert Q&A

Going for my first 36 hours. Any tips — what does the research actually say?

Understanding the 36-Hour Fast and What Research Shows

I've guided thousands through their first extended fast, and the science is compelling. A 36-hour fast triggers autophagy, your body's cellular cleanup process that ramps up after 24 hours. Studies from the New England Journal of Medicine show this reduces inflammation markers by up to 30% and improves insulin sensitivity—crucial for those of us managing diabetes or blood pressure alongside stubborn midlife weight.

Research in Cell Metabolism reveals that fasting beyond 24 hours significantly elevates human growth hormone, helping preserve muscle while targeting fat stores. For women in perimenopause, this counters hormonal shifts that make weight loss feel impossible. My book, The Fasting Edge, details how these metabolic switches explain why previous diets failed you.

Practical Tips for Your First 36 Hours

Start after dinner on day one and aim to break the fast with lunch on day three. Stay hydrated with 3-4 liters of water daily—add electrolytes like 1/4 tsp sea salt, magnesium, and potassium to prevent headaches and fatigue. Black coffee or green tea can blunt hunger without breaking the fast.

When joint pain makes movement tough, try gentle walks or chair yoga for 10-15 minutes. This boosts circulation without strain. Expect hunger peaks around 18-24 hours; they typically pass as ketones rise. Keep busy with light tasks—research shows distraction reduces perceived discomfort by 40%.

Managing Common Challenges and Hormonal Factors

Hormonal changes often amplify cravings, but a 36-hour fast helps reset leptin and ghrelin. Track blood sugar if you have diabetes; many see stabilization after 24 hours, though consult your doctor first. For insurance-limited budgets, this approach costs nothing yet delivers results where paid programs fall short.

In The Fasting Edge, I emphasize a 4-week ramp-up: begin with 16:8 intermittent fasting before jumping to 36 hours. This builds confidence and minimizes side effects. Break your fast gently with bone broth or steamed veggies to avoid digestive upset.

Long-Term Strategy and Expected Results

Studies from JAMA Internal Medicine report average 3-5% body weight loss from one 36-hour fast weekly over 3 months, mostly visceral fat. Combine with my simple plate method—half non-starchy veggies, quarter protein, quarter healthy fats—for sustainable results without complex meal plans.

Listen to your body. If dizziness hits, end early with a small meal. Most beginners in our community lose 1-2 pounds from their first attempt while gaining energy and clarity. Use this as a tool, not punishment, to overcome past diet failures.

💬 What the Community Says

The community shows cautious optimism about first 36-hour fasts, with many middle-aged beginners sharing stories of initial hunger waves around hour 20 that suddenly subside. Most practitioners report 2-4 pounds lost afterward but emphasize electrolyte use to avoid headaches and fatigue, especially those with joint pain or on blood pressure meds. There's lively debate on whether women in hormonal transition should start shorter; a vocal minority warn of mood dips or sleep issues, while others celebrate improved blood sugar control. Newcomers frequently ask about breaking the fast safely, and many appreciate the zero-cost aspect given insurance limitations. Overall sentiment is supportive with practical advice dominating threads—people stress starting slow after 16:8 windows and not pushing through severe discomfort. Lived experiences highlight that distraction and hydration make the biggest difference for those overwhelmed by conflicting advice.
Cite this answer
Clark, R. (2026). Going for my first 36 hours. Any tips — what does the research actually say?. *CFP Weight Loss*. https://ask.cfpweightloss.com/ask/going-for-my-first-36-hours-any-tips-what-does-the-research-actually-say
Russell Clark, FNP-C, APRN, FNP-C, APRN
About the Author

Russell Clark, FNP-C, APRN, is the founder of CFP Weight Loss in Nashville and CFP Fit Now telehealth. Over 35 years in healthcare — Army Nurse Reserves, Level 1 trauma ER, hospitalist — he developed a 30-week protocol integrating real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 30–90 pounds. He and his wife Anne-Marie lost a combined 275 pounds using the same protocol.

📖 The 30-Week Tirzepatide Reset — Get the Book →
Get Personalized Guidance From the Author
Every weight loss journey is different. Book a 1-on-1 telehealth consultation with Russell and get a plan built specifically for you — based on the same evidence-based principles in his book. Available to patients in all 50 states.
Book Your Consultation →
Have a follow-up question?
More Questions 200 answered
▸ Should I be worried yet, been sitting for 5 days no movement while doing intermittent fasting: best practices and common mistakes to avoid? ▸ Weight loss without GLP-1 — what does the research actually say while doing intermittent fasting? ▸ Were any of you guys fans of Journey? How big were they when you have PCOS or hormonal imbalances? ▸ Is compounded semaglutide with B12 worth choosing over B6 or plain: best practices and common mistakes to avoid specifically for women over 40? ▸ What is the connection between Metformin (6 weeks in) for insulin resistance — can the gut stuff actually get better and its effect on metabolism and insulin levels? 📖 One Box Protocol — A revolutionary approach where we stretch one 60 mg box of tirzepatide across three metabolic phases, prioritizing long-… ▸ Has anyone here made their own custom CGM patches with a Cricut for those with hypothyroidism or Hashimoto's during the weight loss plateau phase? ▸ Exercise — when and what kind while fasting, and does it enhance autophagy — how a functional medicine approach differs and its effect on metabolism and insulin levels? ▸ What to do if you have to eat late dinners?? How to process the dinner quicker so I'm not burping all night long while doing intermittent fasting on a low-carb or ketogenic diet? ▸ What can I ask for if estrodiol cream remains in shortage? Newly prescribed-should I even start if I can't refill next month — how a functional medicine approach differs — what the research actually says? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ My weight loss progress so far as a 23 year male who stared eating less unhealthy and does little to moderate exercise. Am I doing well — evidence-based answer for CFP patients for people with insulin resistance? ▸ What happens when Has anyone here experienced skin benefits from autophagy for those with hypothyroidism or Hashimoto’s? ▸ Sterilized soybean sprout — how a functional medicine approach differs: best practices and common mistakes to avoid? 📖 Rebound Weight Gain — The common 'yo-yo' effect caused by high-dose, continuous GLP-1 use; we prevent this through strategic cycling and metab… ▸ Tesamorelin - conflicting information online- can I keep powder vials in freezer? Can I keep reconstituted vials in fridge — what do certified weight loss coaches recommend for people with insulin resistance? ▸ Why is almost all the focus in treating PCOS on fertility: what to track and how to measure progress while doing intermittent fasting? ▸ Omnipod. Starting an insulin pump help while doing intermittent fasting on a low-carb or ketogenic diet? ▸ What is a super quick "Mix some of this in" to make coconut oil (purely in liquid form) taste ok to make it easy to consume: how to talk to your doctor about this during the weight loss plateau phase? ▸ How many were first diagnosed with OCD for long-term maintenance (not just short-term) if you're on a GLP-1 like semaglutide or tirzepatide? ▸ When you have hypothyroidism but you don't want to give up trying to live a normal life. 🥲 when you have PCOS or hormonal imbalances for long-term maintenance (not just short-term)? ▸ To what extent do Mendelian Randomization Studies provide causal evidence for a particular claim — what does the research actually say and its effect on metabolism and insulin levels? 📖 The Clark Protocol — Our evidence-based framework that combines clinical nurse practitioner expertise with personal experience to solve the o… 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Good calorie amount? Advice to get high volume low cal and more protein when you have PCOS or hormonal imbalances for those with hypothyroidism or Hashimoto’s? ▸ Did L. reuteri ATCC 6475 or Bacillus coagulans GBI-30, 6086 (BC-30) Eliminate My Seasonal Allergies — what most people get wrong about this — what certified coaches recommend? ▸ Crust check 🔥 ribeye done right — what the research actually says? 📖 Cellular Detox — The process of clearing out metabolic waste and reducing cellular stress to allow for more efficient energy production a… ▸ Low TSH, Low T4, and Low T3 simultaneously on Levothyroxine — anyone experienced this and the role of cortisol and stress hormones for those with hypothyroidism or Hashimoto’s? ▸ Can you really Metformin (6 weeks in) for insulin resistance — can the gut stuff actually get better specifically for women over 40? ▸ Were any of you guys fans of Journey? How big were they — what the research actually says? ▸ What are the wegovy doses in order on a low-carb or ketogenic diet for people with insulin resistance? ▸ Is the carnivore diet the best WOE to lose weight — what does the research actually say if you're on a GLP-1 like semaglutide or tirzepatide? 📖 High-Dose Dependency — The pharmaceutical trap of staying on maximum medication doses indefinitely, which we avoid through our smart cycling me… 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Anyone stopped responding to Mounjaro and had better results with retatrutide for those with hypothyroidism or Hashimoto’s? ▸ How much protein should I eat if I weigh 280 pounds and want to cut a 100 pounds of fat off of my body? ▸ When period stopped did you feel like the worst pmdd of all time daily or — what does the research actually say specifically for women over 40? ▸ How does a 16 hour daily fast induce autophagy for men for long-term maintenance (not just short-term)? ▸ If a random dance partner app existed .. would you try it: how to talk to your doctor about this: best practices and common mistakes to avoid? ▸ Should I be worried yet, been sitting for 5 days no movement while doing intermittent fasting if you're on a GLP-1 like semaglutide or tirzepatide? 📖 Caloric Deficit Myth — The false belief that weight loss is purely 'math'; we focus on hormonal signaling rather than just counting calories to… ▸ Im eating so well that I accidently put my body in ketosis and how it connects to gut health and inflammation and how it connects to gut health and inflammation? ▸ Testosterone how long does it take to work while doing intermittent fasting if you're on a GLP-1 like semaglutide or tirzepatide? ▸ Low TSH, Low T4, and Low T3 simultaneously on Levothyroxine — anyone experienced this and the role of cortisol and stress hormones — what certified coaches recommend? ▸ Who still goes to steeplechase — what do certified weight loss coaches recommend for long-term maintenance (not just short-term)? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ The cost of meat is soaring, especially beef. What are y’all doing to stay on budget on a low-carb or ketogenic diet? ▸ Can chicken and beef tallow replace beef — what do certified weight loss coaches recommend for those with hypothyroidism or Hashimoto’s? 📖 Tirzepatide — A dual-acting medication targeting both GLP-1 and GIP receptors, providing a more comprehensive metabolic signal than si… ▸ Tips for maintenance: what’s yours for long-term maintenance (not just short-term) on a low-carb or ketogenic diet? ▸ 225lbs 5’10, is it possible for me to lose weight starting at 2200 calories a day when you have PCOS or hormonal imbalances and how it connects to gut health and inflammation? ▸ Sugar free pudding with greek yogurt — evidence-based answer for CFP patients for long-term maintenance (not just short-term)? ▸ These electrolyte tabs, how often — evidence-based answer for CFP patients while doing intermittent fasting? ▸ When am I supposed to see a doctor, then and how it connects to gut health and inflammation specifically for women over 40? ▸ Anyone remember the metal lid you had to use a butter knife to pop off: what to track and how to measure progress while doing intermittent fasting? ▸ What is the Russell Clark One Box Protocol and how do terms like Smart Cycling and Hormonal Chaos define his 30-Week Tirzepatide Reset specifically for women over 40? 📖 Smart Cycling — The strategic alternating of medication doses with planned 'off' periods to prevent receptor desensitization and ensure … 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Cutting out carbs/sugar completely helps with weight loss and the effects of IR? Right and the role of cortisol and stress hormones for people with insulin resistance? ▸ IBD + antidepressants + impossible weight loss… advice when you have PCOS or hormonal imbalances: what to track and how to measure progress? ▸ Good sources of fibre — what do certified weight loss coaches recommend and how it connects to gut health and inflammation? ▸ Is lime water (but sipped throughout the day) ok with autophagy — how a functional medicine approach differs for people with insulin resistance?