Expert Q&A

Should I continue my fast or no and its effect on metabolism and insulin levels

Understanding Fasting's Impact on Insulin Levels

As the founder of CFP Weight Loss and author of The CFP Method, I've helped thousands of adults aged 45-54 navigate weight loss despite hormonal shifts, joint pain, and prior diet failures. When it comes to whether you should continue your fast, the key lies in how fasting influences your insulin levels.

After 12-16 hours without food, insulin drops significantly—often by 50% or more—allowing your body to access stored fat for energy. This process, called lipolysis, is particularly beneficial if you're managing diabetes or blood pressure alongside obesity. In my CFP Method, we emphasize starting with 14-hour overnight fasts to gently lower insulin without overwhelming your system. For middle-income families with busy schedules, this requires no expensive programs or complex plans—just consistent timing.

How Fasting Affects Your Metabolism

Many fear fasting slows metabolism, but research shows short-term fasts (16-24 hours) can actually increase metabolic rate by 3-14% through elevated norepinephrine. However, extended fasts beyond 48 hours without proper refeeding may reduce thyroid output and basal metabolic rate by up to 15%, especially in women experiencing perimenopause.

In The CFP Method, we recommend cycling fasts—16:8 most days, with two non-fasting days weekly—to preserve muscle and keep metabolism humming. This approach has helped clients lose 20-40 pounds while reducing joint pain, as lower insulin decreases inflammation. If you've failed every diet before, know that metabolic adaptation is why; our method counters it with strategic protein intake (1.2g per kg body weight) on eating windows.

Deciding Whether to Continue Your Fast

Listen to your body. Continue if you feel energized, experience stable blood sugar, and have no dizziness after 16 hours. Stop and eat a balanced meal with protein and healthy fats if you feel weak, irritable, or overly hungry—these signal cortisol spikes that can worsen hormonal weight gain. For beginners overwhelmed by conflicting advice, track your fasting with a simple app and aim for consistency over perfection. Insurance rarely covers these programs, so our at-home CFP approach focuses on sustainable changes that fit your life without gym schedules.

Practical Tips to Optimize Fasting Results

Break your fast with bone broth or a small protein meal to ease digestion. Stay hydrated with electrolytes—sodium, potassium, magnesium—to combat fatigue common in this age group. Combine with gentle movement like walking to ease joint pain; even 20 minutes daily boosts insulin sensitivity by 25%. In my experience, clients who pair fasting with stress management see the best long-term success, dropping both weight and A1C levels. Start small, build confidence, and remember: this isn't another failed diet—it's a metabolic reset tailored for real life.

💬 What the Community Says

The community shows mixed but cautiously optimistic experiences with fasting for weight loss after 45. Many in online forums report improved energy and lower blood sugar after adopting 16:8 intermittent fasting, especially those managing diabetes or high blood pressure. A common theme is initial success followed by plateaus, leading some to question if metabolism slows with prolonged use. Beginners often share embarrassment about obesity and relief finding simple schedules that don't require expensive programs or intense exercise that aggravates joint pain. There's debate around hormonal changes in women, with some noting better results when adding strength training or cycling fasting days. A vocal minority warns against extended fasts without medical guidance, citing fatigue or hair loss, while most practitioners emphasize listening to the body and combining fasting with protein-rich refeeds. Overall, lived experiences highlight that consistency beats perfection, though conflicting nutrition advice leaves many feeling overwhelmed at the start.
Clark, R. (2026). Should I continue my fast or no and its effect on metabolism and insulin levels. *CFP Weight Loss*. https://ask.cfpweightloss.com/ask/should-i-continue-my-fast-or-no-and-its-effect-on-metabolism-and-insulin-levels
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.

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
▸ Will eating meintenance calories make me lose weight for those with hypothyroidism or Hashimoto's when you have PCOS or hormonal imbalances? ▸ Fitter or kidding myself: how to talk to your doctor about this if you're on a GLP-1 like semaglutide or tirzepatide? ▸ What is your immediate go to for some relief during ha — what most people get wrong about this — what certified coaches recommend? ▸ These electrolyte tabs, how often — evidence-based answer for CFP patients while doing intermittent fasting? ▸ 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 those with hypothyroidism or Hashimoto’s? 📖 Caloric Deficit Myth — The false belief that weight loss is purely 'math'; we focus on hormonal signaling rather than just counting calories to… ▸ Crust check 🔥 ribeye done right — what the research actually says? ▸ Why cant i lose weight and am gaining weight when you have PCOS or hormonal imbalances for those with hypothyroidism or Hashimoto’s? ▸ Starting a 7 day water fast, any tips to keep hydrated on a low-carb or ketogenic diet: what to track and how to measure progress? ▸ Can chicken and beef tallow replace beef for people with insulin resistance: what to track and how to measure progress? 📖 Refined Carbohydrates — Processed sugars and flours that strip the body of nutrients while driving the hormonal chaos responsible for the modern… 📗 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 ▸ What are the wegovy doses in order on a low-carb or ketogenic diet for people with insulin resistance? ▸ When you want something sweet but still try to keep things somewhat low-carb and how it connects to gut health and inflammation on a low-carb or ketogenic diet? ▸ 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? ▸ LDN is changing my life, will this last: best practices and common mistakes to avoid: what to track and how to measure progress? ▸ 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? ▸ How much protein should I eat if I weigh 280 pounds and want to cut a 100 pounds of fat off of my body? 📖 The Clark Protocol — Our evidence-based framework that combines clinical nurse practitioner expertise with personal experience to solve the o… ▸ Diabetics with TPN (IV nutrition experience) and the role of cortisol and stress hormones on a low-carb or ketogenic diet? ▸ 42yom Im finding it much harder to lose weight, what are some things I can do now to start losing weight? 📗 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 ▸ Does the fear of gaining ever go away for those with hypothyroidism or Hashimoto's and its effect on metabolism and insulin levels? ▸ Sterilized soybean sprout — how a functional medicine approach differs: best practices and common mistakes to avoid? 📖 Anti-Inflammatory Protocol — A way of eating that prioritizes whole foods and eliminates triggers to quiet the internal 'fire' that prevents fat cell… ▸ What are the wegovy doses in order on a low-carb or ketogenic diet if you're on a GLP-1 like semaglutide or tirzepatide? ▸ Does mental health predict diabetes as much as BMI? Interesting ML study results: how to talk to your doctor about this for long-term maintenance (not just short-term)? ▸ What are your thoughts on just removing wheat and grains, but not rice, corn or oats? Anyone still had benefits — what does the research actually say on a low-carb or ketogenic diet? 📖 GIP (Gastric Inhibitory Polypeptide) — A hormone that, when combined with GLP-1, enhances the body’s ability to break down fat and manage blood sugar levels mo… ▸ Has anybody heard of or experienced improvement from neurological disorders through fasting and autophagy if you're on a GLP-1 like semaglutide or tirzepatide — what certified coaches recommend? ▸ Is lime water (but sipped throughout the day) ok with autophagy — how a functional medicine approach differs for people with insulin resistance? ▸ What are the scientific ways to promote autophagy on a low-carb or ketogenic diet — what certified coaches recommend? 📖 Metabolic Flexibility — The body’s ability to efficiently switch between burning carbohydrates and burning stored body fat based on availability… 📗 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 ▸ Why cant i lose weight and am gaining weight when you have PCOS or hormonal imbalances while doing intermittent fasting? ▸ 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? ▸ Omnipod. Starting an insulin pump help while doing intermittent fasting for long-term maintenance (not just short-term)? ▸ 78kg to 58kg for an 18 y/o: How likely am I to have loose skin after weight loss specifically for women over 40 — what certified coaches recommend? ▸ 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? ▸ 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? ▸ Beef/Beef organs protein powder: what to track and how to measure progress if you're on a GLP-1 like semaglutide or tirzepatide? 📖 Amylopectin A — The specific starch found in modern wheat that causes rapid, dangerous spikes in blood glucose and promotes belly fat st… ▸ Should I be worried yet, been sitting for 5 days no movement while doing intermittent fasting: best practices and common mistakes to avoid? ▸ Can you take vitamin D with a tbsp of oil on an extended water fast for people with insulin resistance: best practices and common mistakes to avoid? 📗 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 ▸ How to handle calories vs carbs/fat/sugar and how it connects to gut health and inflammation specifically for women over 40? ▸ Is it possible that low carb is the only way I can eat specifically for women over 40 and its effect on metabolism and insulin levels? 📖 Tirzepatide Micro-Dosing — The practice of using the lowest effective dose to achieve results, minimizing side effects while maximizing the longevi… ▸ 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 and its effect on metabolism and insulin levels? ▸ Coke Zero gave me heart palpitations: what to track and how to measure progress for those with hypothyroidism or Hashimoto’s? ▸ Is it okay for teenagers to do longterm lowcarb/keto — evidence-based answer for CFP patients for those with hypothyroidism or Hashimoto’s? ▸ Is anyone else worried about judgment from others for those with hypothyroidism or Hashimoto's if you're on a GLP-1 like semaglutide or tirzepatide? ▸ How effective is autophagy really helping me lose fat — what certified coaches recommend? ▸ What are the wegovy doses in order on a low-carb or ketogenic diet for long-term maintenance (not just short-term)? ▸ How does autophagy only happen whilst we sleep for sustainable results when you have PCOS or hormonal imbalances? 📖 Hormonal Chaos — The internal state of imbalance caused by modern grains and refined carbs that overrides willpower and forces the body t… ▸ 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 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 ▸ How much keto-ade should I safely drink: best practices and common mistakes to avoid and how it connects to gut health and inflammation? ▸ 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 while doing intermittent fasting? ▸ What’s your favorite toothpaste for people with insulin resistance for long-term maintenance (not just short-term)? 📖 CICO (Calories In, Calories Out) — An outdated model of weight loss that ignores the role of hormones; we challenge this by focusing on food quality and ho… ▸ These electrolyte tabs, how often — evidence-based answer for CFP patients specifically for women over 40? ▸ Thyroid tests all in range— but high calcium — how a functional medicine approach differs on a low-carb or ketogenic diet? ▸ Does drinking Sparkling Ice (flavored sparkling water - 5 calories per bottle) during my fasting window break my fast and the role of cortisol and stress hormones during the weight loss plateau phase?