Ask the Doc: How Fasting Affects Females Differently, Causes and Treatments for PMS, Why HbA1C is an ‘Unreliable’ Marker, and More

May 16, 2016


This episode is brought to you by SKORA Runningcrafting running shoes that incorporate what nature intended with what the best technology can enhance. Find out more and shop now at SKORA.

Dr. Tommy Wood is back for his 4th round as our resident export for Ask the Doc. Tommy is a medical doctor, with degrees from Oxford University and Cambridge University. He’s currently working toward a Ph.D. in neonatal brain metabolism at the University of Oslo, Norway. He is also an athlete, specializes in working with endurance athletes, and he takes the functional approach to practicing medicine for optimal health, wellness and performance. Tommy consults with athletes via Nourish Balance Thrive. You can also submit a question to Tommy for future ATD episodes at

Announcements: Tommy will be speaking at the Biohacker Summit in London on May 21, and the Icelandic Health Symposium on May 26, along with Dr. Tim Noakes. Check it out if you’re in town!

On this show:

One supplement for all?

Causes and treatments for PMS

Intermittent fasting & fasting for women (not the same results as for men)

  • Can IF/fasting work for guys but be detrimental for women?
  • This well-written, well-researched article highlights potential harms of fasting for women (athlete or not) by Stefani of Paleo for Women 
  • Why Tommy and Tawnee never recommend alternate day fasting for females
  • Most lab studies are using male rats, Tommy explain why, and also how this is not optimal to determine what’s best for women
  • 6:1 ratio of male to female rats used in any research regarding the brain
  • Women incur more stress with intermittent fasting, and if you then combine this with endurance exercise stress it becomes extra risky. Likely to develop into female athlete triad symptoms including loss of menstruation.
  • What if a female (athlete or not) doesn’t care about having her period–is this ok? Tommy explains pros and cons.
  • Ideal diet protocol for females: How to eat healthy, avoid crappy carbs, eat for fat adaptation but avoid doing damage of eating too little or fasting
  • Tying this back in with menstruation:
  • Females are most insulin sensitive during the follicular phase (1st phase)
  • Females are more insulin resistant during luteal phase (2nd phase, including PMS time)
  • Oddly, a high carb low fat meal can offset or mitigate PMS symptoms. On the other hand, eating high-fat low-carb during the luteal phase may be optimal for health and insulin response.
  • Tawnee chimes in on her personal experience with diet during different phases.

Do we need carbs to be a good fat-burner?

  • Do we literally need to ingest some carbs to allow for and/or optimize fat burning? Or can we go low carb/no carb pre- and during-training/races and still be a kick ass fat-burner?
  • Low carb vs no carb = big difference
  • Going too low carb/no carb can starve microbiome
  • If you fast you don’t get mitochondrial biogenesis, we need/want mitochondrial biogenesis so don’t fast too much
  • The role of AMPK – we want to stimulate AMPK because it has a positive effect on the way muscle cells use glucose and fatty acid oxidation
  • Exercise is the most powerful physiological activator of AMPK
  • More on glycogen cycling/replenishment for athletes and why it’s important!

Is HbAIC a poor predictor of blood sugar control and disease risk?

  • EP fan says he’s doing it all right with diet, exercise, etc, yet HbA1C and fasting glucose were high. What gives?
  • Most blood tests assess hemoglobin A1C (HbA1c) as a way to get a snapshot of blood sugar/glucose control for the past 90 days, screen for and diagnose diabetes and prediabetes in adults, but is it reliable?
  • Tommy says his HbA1C is also highish as well, at 5.7%
  • Article on HbA1C by Keith Runyan that we mention on the show as a good resource to back up our statements
  • An A1C of 6.0 supposedly indicates blood glucose could have been 100-152; an A1C of 5.0% indicated blood glucose of 76-120.
  • A1C is actually largely determined by genetics (up to 50%)
  • Looking at RBCs – the average lifespan of an RBC is 115-120 days, but in athletes they may have increased turnover of RBCs due to foot strike hemolysis, and this could lead to higher MCV due to the blood cell breakdown
  • Take-home: Don’t use A1C to calculate average blood glucose! Instead get an at-home glucometer to monitor especially 2-4 hours after eating.
  • Supplies offered by Nourish Balance Thrive
  • As for higher fasting blood glucose this could be due to higher stress, bad sleep, coffee, etc. Re-test.

Comments (4)

  • Deanna Fostet says:

    You do a great job specifying when a health con seen or difference is gender specific, but could you please let the listeners know when it may be different for the 50+ female athlete who doesn’t have to worry about periods anymore. Or even if you don’t know is good to. I’ve never heard anyone specify any differences.

  • Corry fitzgibbons says:

    Is there a link to the report about vitamin d and neuronal health for Pms?

    • Tawnee_Prazak says:

      I just updated the show notes with another research paper from Tommy. Titled "Update on Research and Treatment of Premenstrual Dysphoric Disorder." Hope that helps!

Add your thoughts

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.