Fasting Claims, Collagen for Cellulite, and Who to Trust in Women's Health

Episode Summary
A solo Mini-Mikkipedia. Mikki is often asked how to tell whether someone in the women's health space is worth following, and in this episode she answers it by working through two examples of what she thinks has gone wrong: practitioners who build large audiences on free information and then, in her view, monetise their followers' insecurities.
The first half is physiology. Mikki takes two specific claims made about fasting — that it preserves muscle through growth hormone, and that it raises GLP-1 enough to make a medication unnecessary — and explains why she thinks both are wrong: the anabolic effect needs IGF-1, which needs protein and energy, and GLP-1 is a nutrient-sensing hormone that responds to food arriving in the gut. She is careful to separate that from where she thinks fasting genuinely earns its place, and to state the version of the GLP-1 claim that can be defended. The second half looks at a collagen supplement marketed for cellulite: what the one cellulite trial actually found, what a 2025 review found once industry-funded trials were separated out, and why she thinks cellulite is the wrong thing to be selling women anything for. She closes with the people she does think are worth following. Mikki is explicit that this is her opinion — "I'm just telling you what I think" — and equally explicit that she is not making a supplement of her own.
Key Topics
  • How to judge whether someone in the women's health space is worth following, and the pattern Mikki looks for: free information that turns out to be a funnel
  • Why Mikki fact-checked Fast Like a Girl and concluded the evidence base was mechanistic, preclinical or wrong, and what she has seen in clients who followed the protocol
  • Where fasting genuinely earns its place — severe insulin resistance, some gut issues, and as a researched adjunct in cancer treatment — and why 12 hours overnight is not really fasting
  • The growth hormone argument: why an increase in growth hormone without an increase in IGF-1 does not build or protect muscle, and why the reported percentage increases are inflated by a near-zero baseline
  • Why fasting cannot raise GLP-1, since GLP-1 is secreted by enteroendocrine L-cells in response to protein, fat and fermentable fibre arriving in the gut — and the one version of the claim that can be defended
  • The collagen supplement marketed on the back of a story about cellulite, and Mikki's objection to the marketing rather than to collagen itself
  • What the cellulite trial actually found: 105 women, 2.5 g of collagen peptides daily for six months, a 9% reduction in cellulite score at normal BMI and 4% above BMI 25 — and nothing replicating it in the decade since
  • The 2025 review of 23 trials where collagen improved skin hydration, elasticity and wrinkles overall, but showed no effect in the trials without industry funding
  • Why Mikki thinks cellulite is the wrong focus altogether, and her answer to the pushback that she talks about women's bodies herself
  • Who she suggests following instead, and why she has turned down several approaches to make her own supplement
Chapters
00:00 Introduction and Fast Like a Girl
03:15 Where fasting is genuinely useful
05:33 Growth hormone, IGF-1 and the GLP-1 claim
09:46 Mary Claire Haver's cellulite supplement
13:20 Collagen, funding and the wrong focus
16:55 Who to follow in women's health
Guest / Resources
Guest
No guest — a solo Mini-Mikkipedia episode.
People discussed
  • Dr Mindy Pelz — author of the Fast Like a Girl system, discussed critically throughout the first half
  • Dr Mary Claire Haver — discussed in relation to a collagen supplement marketed for cellulite
  • Dom D'Agostino — referenced for his research on ketogenic diets and fasting, including fasting as an adjunct to cancer treatment
People Mikki recommends following
  • Hailey Babcock — Hailey Happens Fitness, strength training and nutrition for women in midlife
  • Dr Abbie Smith-Ryan — Professor of Exercise Physiology and Nutrition, University of North Carolina at Chapel Hill
  • Dr Stacy Sims — exercise physiologist and nutrition scientist, known for her work on female athletes
  • Jen Kirsch and Holly Nicholson — also named by Mikki as people worth following
Studies and research discussed
  • Schunck M, Zague V, Oesser S, Proksch E. Dietary Supplementation with Specific Collagen Peptides Has a Body Mass Index-Dependent Beneficial Effect on Cellulite Morphology. Journal of Medicinal Food, 2015;18(12):1340–1348. The cellulite trial Mikki describes: 105 women aged 24–50 with moderate cellulite, randomised to 2.5 g bioactive collagen peptides or placebo daily for six months
  • Myung S-K, Park Y. Effects of Collagen Supplements on Skin Aging: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. The American Journal of Medicine, 2025. 23 randomised controlled trials, 1,474 participants. Collagen improved skin hydration, elasticity and wrinkles overall, but trials without industry funding showed no effect on any of the three
  • Collagen peptides, pain and function in active adults — research from Michael Ormsbee's lab at Florida State University, in physically active adults aged 40–65, using 10 g of collagen peptides daily for six months. This is the pain and function work Mikki refers to, and the source of the 10 g comparison she draws
Ingredients discussed
  • Fortibone — collagen peptide type discussed for bone and tendon health
  • Verisol — collagen peptide type studied for skin, and used in the cellulite trial above
Concepts covered
GLP-1 and enteroendocrine L-cells · growth hormone and IGF-1 · insulin resistance · time-restricted eating · mechanistic and preclinical versus clinical evidence · industry funding and publication bias

Contact Mikki:
https://mikkiwilliden.com/
https://www.facebook.com/mikkiwillidennutrition
https://www.instagram.com/mikkiwilliden/
https://linktr.ee/mikkiwilliden
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