Why Women Gain Weight on the Same Diet as Men: Fueling, Fasting, and Biology with Dr. Stacy Sims

In this episode of unPAUSED, Dr. Mary Claire Haver sits down with exercise physiologist and nutrition scientist Dr. Stacy Sims to unpack why so much fitness and diet advice built on male physiology leaves women confused about why the scale will not move, and why weight loss can feel so much harder for women than for men on the exact same plan. Dr. Sims, author of Roar and Next Level, a former professional cyclist who has taught and coached at Stanford, breaks down why women following the same diet and training program as their male partners often end up tired and stuck rather than leaner and fitter. The conversation covers the biological reasons women conserve fat in a calorie deficit, how female circadian rhythm differs from male circadian rhythm, and why eating within an hour of waking helps regulate cortisol and appetite hormones like ghrelin and peptide YY. Dr. Sims explains why fasted workouts can backfire for women, why front loading calories earlier in the day supports better metabolic outcomes, and why time restricted eating works with a woman's biology in ways that intermittent fasting often does not. Guest links: Dr. Stacy Sims https://www.drstacysims.com/ Dr. Stacy Sims (Facebook)   / drstacysims   Dr. Stacy Sims (YouTube)    / @drstacysims   Dr. Stacy Sims (Instagram)   / drstacysims   Stacy T. Sims, PhD (LinkedIn)   / stacy-t-sims-phd   Dr. Stacy Sims Newsletter https://www.drstacysims.com/generic_o... Dr. Stacy Sims Microlearning Course https://www.drstacysims.com/microlear... Books: “Next Level: Your Guide to Kicking Ass, Feeling Great, and Crushing Goals Through Menopause and Beyond,” by Dr. Stacy Sims https://www.amazon.com/Next-Level-Kic... “ROAR: How to Match Your Food and Fitness to Your Unique Female Physiology for Optimum Performance, Great Health, and a Strong, Lean Body for Life,” by Dr. Stacy Sims https://www.amazon.com/ROAR-Fitness-P... “The New Perimenopause,” by Dr. Mary Claire Haver https://www.amazon.com/New-Menopause-... “The New Menopause,"⁠ by Dr. Mary Claire Haver https://www.amazon.com/New-Menopause-... For full show notes, please visit: https://bit.ly/unPAUSEDDrStacySims 00:00:00 – Why Calories Don't Tell the Whole Story 00:01:54 – Meet Dr. Stacy Sims 00:05:00 – Women Are Not Small Men 00:11:48 – Why Women Struggle to Lose Weight 00:17:17 – The Truth About Circadian Rhythm 00:27:17 – Should Women Exercise Fasted? 00:31:58 – How to Build Muscle After 40 00:38:04 – The Best Workout for Menopause 00:44:15 – Intermittent Fasting vs. Time-Restricted Eating 00:49:48 – Dr. Stacy Sims' Daily Nutrition Routine 00:53:53 – Why Exercise Beats Dieting 01:04:07 – Train for Healthspan, Not Weight Loss Never miss an episode—sign up for The ’Pause Life Newsletter: https://thepauselife.com/pages/newsle... Medical Disclaimer: The information, including opinions and recommendations, on this platform is meant for informational and educational purposes only. Mary Claire Media, LLC, the unPAUSED podcast, and The ’Pause Life are not medical organizations. Medical advice or medical diagnosis cannot be provided to you through the platform, any associated website, or customer portals. Using this platform does not establish a patient-physician relationship.