About this episode

Dr. Mary Claire Haver discusses with Dr. Stacy Sims the reasons why women struggle with weight loss on the same diet as men, focusing on biological differences and dietary strategies.

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 Dr. Stacy Sims ( Facebook ) Dr. Stacy…

People in this episode

Host: Dr. Mary Claire Haver

Guest: Dr. Stacy Sims

Topics covered

• weight loss
• female physiology
• diet and nutrition
• exercise science
• metabolism
• hormones

Keywords

• weight gain
• calorie deficit
• circadian rhythm
• fasted workouts
• time restricted eating
• metabolic outcomes
• hormone regulation

Mentioned in this episode

Books & works: Roar, Next Level, The New Perimenopause, The New Menopause

More episodes of unPAUSED with Dr. Mary Claire Haver

• The Ovary’s Job Doesn’t End at Menopause: A Top Neuroscientist Explains · July 21, 2026 · 1h 11m
• Lift Heavy, Protect Your Brain: Strength, Creatine, and Sauna for Women with Dr. Stacy Sims · July 17, 2026 · 42 min
• Vanishing Vulvas & Menopause: What's Really Happening with Dr. Karen Tang · July 10, 2026 · 34 min
• Endometriosis and Fibroids Don't Stop at Menopause with Dr. Karen Tang · July 7, 2026 · 1h 5m
• Introducing Family Lore · July 5, 2026 · 3 min
• Gut, Brain, and Hormones: The Menopause Connection with Dr. Amy Shah · June 30, 2026 · 1h 20m

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