If you’ve been paying attention in the low-carb and/or Paleo communities over the past year or so, then no doubt you’ve heard the popular meme promoted by certain Paleo diet advocates that zero-carb and very low-carb diets (ketogenic) lead to lower thyroid function, among other issues. They claim that this leads to a diminished capacity for T4 to be converted into T3 thyroid hormone because of the lack of glucose consumed by low-carb dieters. This concept has been heavily promoted by highly-respected practioners like Chris Kresser who sees patients from what he describes as “the dark side of Paleo and low-carb” dealing with hair loss, cold extremities, feeling horrible and other such negative manifestations of experiencing a low thyroid function.
However, two of the top low-carb nutritional health researchers in the world — Dr. Stephen Phinney and Dr. Jeff Volek — say this phenomenon with low thyroid while on a low-carbohydrate diet promoted by people in the Paleo community like Kresser and Paul Jaminet is “a myth” and has not manifested itself in any of the research subjects in their numerous studies of people who are properly following a well-formulated low-carb diet with adequate calories over the past three decades. Dr. Phinney believes the primary point of contention revolves around consuming an adequate amount of calories with your low-carbohydrate nutritional intake in order to normalize thyroid and metabolic function without the necessity for consuming added sources of dietary glucose. Dr. Volek concurs stating that it’s calorie-restriction that brings on this low thyroid effect, not limiting carbohydrates.
The audio footage in this 20-minute video comes from excerpts of interviews that aired in 2012 on my brand new podcast called “Ask The Low-Carb Experts” podcast and you can hear the three interviews from these experts in their entirety by clicking on the links below.
Your comments are welcomed and encouraged, so feel free to share your thoughts about what each of these experts shared. Do you think Kresser is right that it is low-carb diets that tend to lower thyroid function (from the lack of glucose necessary to convert T4 into T3) requiring these nutritional approaches to be avoided by many people? Or do you agree with Phinney and Volek who say it’s calorie-restriction, not carbohydrate-restriction that leads to these thyroid concerns? And if there are those, as Kresser notes, who can become adapted to eating a very low-carb diet without these negative effects on their thyroid function, shouldn’t we be attempting to find out what those people are doing differently (i.e. eating more calories than those who have problems) rather than pointing the finger of blame at this nutritional approach? What say YOU?