Optimal Protein Podcast with Vanessa Spina

In today's Friday recap, Vanessa breaks down seven fascinating takeaways from her conversation with Dr. Khashayar Farzam on testosterone in women, muscle preservation, hormones, and the science of fat loss.
Did you know that women typically have higher circulating concentrations of testosterone than estradiol? And that you can preserve muscle mass during weight loss but still lose strength?
In this episode:
Why testosterone matters for women's health beyond libido
How testosterone changes throughout life and menopause
Total vs. free testosterone and the role of SHBG
What the research actually supports about testosterone therapy in women
Why maintaining muscle mass doesn't always preserve strength
A fascinating case study of fat loss with preserved muscle but declining bench press performance
Practical strategies to support muscle and strength during fat loss
🎧 Listen to Monday's full interview with Dr. Khashayar Farzam:
Women Have MORE Testosterone Than Estrogen?! Testosterone 101, Muscle & Menopause
Research discussed:
Beyond Libido: The Multifaceted Role of Testosterone in Women
Maintenance of Skeletal Muscle Mass Does Not Guarantee Bench Press Performance
Connect with Dr. Farzam: Instagram @truenorthmetabolic
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If you enjoyed today's episode, please share it with a friend and leave a review of the Optimal Protein Podcast! Your support helps us continue bringing you the latest science on protein, metabolic health, muscle, and longevity.
Thank you for listening!
Love,
Vanessa
This podcast is for educational purposes only and does not constitute individualized medical advice.

Did you know women have more circulating testosterone than estrogen when measured in equivalent units? And could testosterone play an overlooked role in muscle growth, metabolism, and healthy aging?
In this episode, Vanessa is joined by Dr. Khashayar Farzam, physician specializing in emergency and obesity medicine, founder of True North Metabolic, and clinical assistant professor at McMaster University.
They unpack the new review Beyond Libido: The Multifaceted Role of Testosterone in Women, exploring testosterone's role in women's health, how levels change with age and menopause, and what the evidence says about testosterone replacement therapy.
PLUS: Dr. Farzam shares a fascinating case study of an experienced lifter who lost nearly 15 lbs of body weight while preserving almost all measured muscle mass—yet still experienced a substantial decline in strength!
Topics covered:
Testosterone in women: muscle, metabolism, motivation, and cognition
Perimenopause, menopause, and hormone replacement therapy
Total vs. free testosterone and why SHBG matters
Insulin resistance, body fat, and hormonal health
How to preserve muscle and strength while losing fat
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Studies Discussed
Beyond Libido: The Multifaceted Role of Testosterone in Women
https://doi.org/10.1093/sxmrev/qeag072
Maintenance of Skeletal Muscle Mass Does Not Guarantee Bench Press Performance: A Body-Composition Case Study
https://doi.org/10.7759/cureus.108557
Connect with Vanessa:
Website: KetogenicGirl.com
Instagram: @ketogenicgirl
Connect with Dr. Farzam:
Instagram: https://www.instagram.com/truenorthmetabolic/
Official Website: https://www.doctorfarzam.com
True North Metabolic: https://www.truenorthmetabolic.com
Love this episode? Please follow the Optimal Protein Podcast, leave a rating and review, and share it with a friend!
Disclaimer: This episode is for educational purposes only and is not personalized medical advice. Please consult your healthcare provider regarding hormone testing or treatment.

Can you use meal timing to lose body fat without sacrificing muscle—and does time-restricted eating actually change what is happening inside your fat cells?
In this Friday episode, Vanessa breaks down 8 of the biggest takeaways from her conversation with world-renowned circadian researcher Dr. Satchin Panda, including fascinating new human research examining time-restricted eating, adipose tissue, inflammation and body composition.
This isn't about extreme fasting or eating one meal a day.
Instead, Vanessa explores how a practical 8–10 hour eating window may fit alongside adequate protein, resistance training and a sustainable calorie deficit—and why simply changing when you stop eating may naturally eliminate some of the least nutritious calories of the day.
In this episode:
• What researchers discovered by examining human fat tissue
• How time-restricted eating affected pathways involved in fat metabolism
• Why your fat cells have their own circadian clocks
• How excess adipose tissue can contribute to inflammation
• Does intermittent fasting cause muscle loss?
• Why protein and resistance training change the conversation
• Why extreme fasting isn't necessary
• The practical case for an 8–10 hour eating window
• Earlier dinner vs. later breakfast—which should you prioritize?
• Why Dr. Panda recommends finishing dinner roughly 3 hours before bed
• How late-night eating may affect glucose regulation
• Why you may not need to eat immediately after waking
• How TRE can unintentionally eliminate alcohol, desserts and late-night snacking
• Why meal timing may offer benefits beyond calorie restriction
• How sleep consistency, daylight, exercise and meal timing work together
• Vanessa's practical framework for losing fat while protecting lean mass
The biggest takeaway: meal timing can be a useful tool, but it doesn't replace the fundamentals. Protein intake, resistance training, overall nutrition, energy balance and sleep still matter enormously.
The goal isn't simply to lose weight.
It's to lose body fat while maintaining the metabolically active muscle you've worked so hard to build.
Listen to Vanessa's full conversation with Dr. Satchin Panda in Monday's episode for the complete discussion of his newest research.
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Vanessa's complete high-protein system features satisfying high-protein recipes, structured meal frameworks, grocery lists and strategies designed to support fat loss while prioritizing lean mass.
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CONNECT WITH VANESSA
Instagram: @ketogenicgirl
Instagram: @optimalproteinpodcast
Join the Optimal Protein Podcast community on Facebook.
This podcast is for educational and informational purposes only and is not medical advice. Always consult your physician or qualified healthcare provider regarding your individual health, nutrition and exercise needs.

What actually happens inside your fat cells when you practice time-restricted eating—and can meal timing help you lose body fat without sacrificing muscle?
Dr. Satchin Panda, one of the world's leading researchers on circadian rhythms and time-restricted eating, returns to the Optimal Protein Podcast to unpack fascinating new human research examining time-restricted eating, body composition, inflammation and changes in gene activity inside fat tissue.
Dr. Panda explains why fat tissue is far more than a passive storage depot. We explore how fat cells have their own circadian clocks, why excess fat can become pro-inflammatory, and how aligning eating and fasting periods may influence the pathways involved in fat breakdown and inflammation.
We also tackle one of the biggest concerns surrounding intermittent fasting: Does time-restricted eating cause muscle loss? Dr. Panda explains why some earlier studies raised this concern, what newer research is showing, and why protein intake, diet quality and resistance training remain essential—especially as we age.
We discuss:
• The new human study examining time-restricted eating and fat tissue
• What researchers discovered about gene activity inside fat cells
• How time-restricted eating may change the way stored fat is mobilized
• Why visceral and excess body fat can become pro-inflammatory
• How the circadian clock coordinates fat metabolism
• Why TRE may naturally reduce calories, alcohol and late-night processed foods
• Whether the benefits extend beyond simple calorie restriction
• Does intermittent fasting cause muscle loss?
• Why adequate protein and resistance training matter during fat loss
• Why an 8–10 hour eating window may be a practical approach
• Earlier dinner vs. later breakfast—which matters more?
• Why Dr. Panda recommends finishing your last meal about 3 hours before bed
• Why he recommends waiting approximately 1–2 hours after waking before breakfast
• Black coffee, morning lattes and whether they "break" the fasting period
• What research in athletes tells us about TRE and body composition
• Meal timing, glucose regulation and metabolic health
• New preliminary research combining meal timing, exercise, daylight exposure and sleep consistency
• The surprising effects observed in older adults after only 60 days
• Dr. Panda's practical framework for organizing sleep, meals, movement and light exposure for healthy aging
Dr. Panda also shares how he structures his own mornings, why consistency matters more than perfection, and the simple daily habits he believes can have an outsized impact on metabolic health and healthy aging.
This conversation goes far beyond "when should I eat?" It's a fascinating look at how protein, resistance training, circadian biology, sleep and meal timing can work together to support fat loss while preserving the muscle we work so hard to build.
RESOURCES
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CONNECT WITH DR. SATCHIN PANDA
Learn more about Dr. Panda's research, books and work on circadian biology and time-restricted eating at SatchinPanda.com and follow him on Instagram and X.
CONNECT WITH VANESSA
Instagram: @ketogenicgirl
Instagram: @optimalproteinpodcast
Optimal Protein Podcast Facebook Community
This podcast is for educational and informational purposes only and is not medical advice. Always consult your physician or qualified healthcare provider regarding your individual health, nutrition and exercise needs.

How many calories does it actually take to build muscle—and do you really need to eat in a surplus?
In this Friday solocast, I recap my conversation with Dr. Milo Wolf, exploring a new paper modeling the energy cost of building muscle and what it means for the familiar advice to "eat more to grow."
We discuss how muscle gain and fat loss can happen together, why protein matters, and how to make your workouts effective when time is limited!
You'll learn:
• Why building muscle doesn't automatically require bulking—and how stored body fat can help supply energy.
• What an energy-cost model can tell us, and why it cannot prescribe your exact calorie needs.
• Milo's protein recommendations for supporting muscle growth and preserving muscle during fat loss.
• How brief, challenging workouts can deliver results.
• Training close to failure, emphasizing the stretched position, and saving time with supersets and drop sets.
• How to approach a calorie deficit while supporting muscle, performance, and recovery.
Plus, I unpack a fascinating mouse study on changes in fat tissue following strength training—even before body weight changed—and explain why mobilizing fat is different from losing it.
Listen to the full interview with Dr. Milo Wolf for our deeper dive into the research!
Explore the PSMF Library, the Tone device and Tone LUX red light therapy at ketogenicgirl.com. Get 20% off with the code VANESSA
This podcast is for informational and educational purposes only and does not constitute medical advice. Consult your qualified healthcare professional for advice specific to your health and circumstances.