glycogen storage capacity question

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glycogen storage capacity question

Postby healthyvegan » Mon Apr 18, 2022 10:05 am

Jeff, on this page; https://www.drmcdougall.com/articles/in ... ransition/

is the often repeated "People who have been “starving” or have been following low-carb (Keto type) diets may also regain 10 pounds of “sugar stores” (called glycogen) deposited in the liver and muscles for quick energy"

However, I read here 10.1093/ajcn/48.2.240 "Glycogen storage capacity and de novo lipogenesis during massive carbohydrate overfeeding in man"

"Glycogen storage capacity in man is approximately 15 g/kg body weight and can accommodate a gain of approximately 500 g before net lipid synthesis contributes to increasing body fat mass. When the glycogen stores are saturated, massive intakes of carbohydrate are disposed of by high carbohydrate-oxidation rates and substantial de novo lipid synthesis (150 g lipid/d using approximately 475 g CHO/d) without postabsorptive hyperglycemia."

On this link https://www.drmcdougall.com/misc/2009nl ... ionate.htm

"The total storage capacity for glycogen is about two pounds. Carbohydrates consumed in excess of our need and beyond our limited storage capacity are not readily stored as body fat. Instead, these excess carbohydrate calories are burned off as heat."

Is it 10 pounds, 2 pounds, 15 g/kg? is there associated water weight with that glycogen that ups it to 10?
That ratio of 150 g lipid to 475 g /cho/d seems to contradict the second McDougall quote.

appreciate the help, I'm teaching 'lions how to eat lettuce' and they demand precision in information!
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Re: glycogen storage capacity question

Postby JeffN » Thu Apr 21, 2022 6:25 am

healthyvegan wrote:Is it 10 pounds, 2 pounds, 15 g/kg? is there associated water weight with that glycogen that ups it to 10?
That ratio of 150 g lipid to 475 g /cho/d seems to contradict the second McDougall quote.

appreciate the help, I'm teaching 'lions how to eat lettuce' and they demand precision in information!


Part of the problem is people are not always clear on what exactly they are referring to and there is some variance/range.

Every gram of glycogen is stored with at least 3 grams of water. To store 10 grams of glycogen, there would also be at least 30 grams of water so the total would be at least 40 grams.

Total glycogen content is about 600 g with about 500 g of glycogen stored in the skeletal muscles with the range being about 300-700. The liver stores about 80 with the range being about 0-160. The numbers are not exact and vary between people based on several factors, including body mass, diet (carbohydrate content), fitness, time between meals, and the intensity and duration of recent physical activity.

So, on average, 600 grams glycogen plus 1800 grams water is 2400 grams/454 grams = 5.28 lbs. If we maxed it out based on the above numbers it would be 700 + 160 g= 860 g glycogen plus 2580 water = 3440/454 = 7.57 lbs.

So going from an empty tank to a full tank (or vice versa) can result in at least a 5-8 lb weight gain (or loss) and, depending on the issues mentioned above, there can be some variance up or down.


Hope that helps
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