Reddit reviews Advanced Nutrition and Human Metabolism

I think they keywords for this are fat metabolism & weight loss physiology. That being said, Gropper's book Advanced Nutrition and Human Metabolism might be the book you're looking for if you're interested in a lengthy textbook on human metabolism & nutrition. Conversely, this blog may be of some use.

just curious, what is your source for this number? i have this book and it gives the following values for protein intake:

• estimated avg daily requirement for adults: 0.66 g/kg body weight ~ 0.3 g/lb body weight
  
• RDA 0.8 g/kg = 0.36 g/lb
  
• recommendation for athletes 1.2-1.8 (or up to 2) g/kg; 2 g/kg = 0.9 g/lb

professor gropper's book is the 'bible' of nutrition.

http://www.amazon.com/Advanced-Nutrition-Metabolism-Sareen-Gropper/dp/0495116572


frayn's book is excellent as well

http://www.amazon.com/Metabolic-Regulation-Perspective-Keith-Frayn/dp/1405183594/ref=sr_1_1?s=books&ie=UTF8&qid=1381764452&sr=1-1&keywords=metabolic+regulation

i dont think you'll ever need another book on human nutrition other than these two.

> correlated by co2 emission

Yeah, ok now we're talking together. The first time around you said vo2 ;) co2 is ofc different, that's the respiratory exchange ratio. Vo2 is oxygen uptake during exercise. One letter that makes a difference.

So, the 20-30% number is pretty much the bottom of glucose utilization in a non-keto adapted person, since the brain uses ~20% and pretty much just glucose.

Then it becomes an issue of liver glycogen being depleted once the time period lengthens, and that's when muscle breakdown kicks in as a means to feed glucose to the brain.

As the stores decrease, glucogenesis ramps up using mostly amino acids.

I'll quote a few passages from a textbook that shows the timeline of what's going on. Those are relevant quotes from the post absorptive metabolism section.

>When glycogenolysis is occurring, the synthesis of glycogen and triacylglycerols in the liver is diminished, and the de novo synthesis of glucose (gluconeogenesis) begins to help maintain blood glucose levels.

This is the start of the post absorptive phase. When liver glycogen starts breaking down, gluconeogenesis starts.

>The brain and other tissues of the CNS are extravagant consumers of glucose, oxidizing it for energy and releasing no gluconeogenic precursors in return. At rest, the brain uses about 20% of the available energy even though it is only about 2% of the body by weight.

Underlining the role of the brain in depleting liver glycogen. Those numbers ~equal the storage capacity of the liver, but the cns is not the only consumer of glucose at this time.

>In the course of an overnight fast, nearly all reserves of liver glycogen and most muscle glycogen have been depleted.

This varies of course, someone used to IF and with a high carb intake and a large evening meal will obviously not be glycogen depleted by morning but it still shows the time frame. An overnight fast is actually usually around 12h and not just the 8 spent sleeping though.

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