article on basal metabolic rate and fasting

[Bo Bolund]

Found an article showing how metabolic rate increases during the first 48 hours during a fast. According to this it would be optimal to fast 48 hours since basal metabolic rate is higher compared to overnight fasted value.


http://www.unu.edu/unupress/food2/UID07E/uid07e1h.gif


"During the first 2 days of starvation there is often a small absolute increase in BMR relative to values obtained after an overnight fast."

on the other hand

http://www.unu.edu/unupress/food2/UID07E/uid07e1i.gif

"Although the rate of protein oxidation (reflected in the rate of urine N excretion) is frequently considered to decrease during prolonged starvation, especially in the obese (see below), several studies have shown that there is often a transient early increase. "

Especially day two and three have increased rate of protein oxidation, making a 48 hours fast less favorable considering potential muscle loss.
Personally I think these are only short term studies and muscle loss is no problem when you fast on a regular intermittent basis.

http://www.unu.edu/unupress/food2/UID07E/uid07e11.htm

[Stuart Mather]

So I wonder how this ties in with the observation by Mike Eades that the 'free amino acid pool' lasts for up to 48 hrs (assuming of course that your last meal contained 'adequate' protein. In other words, while that free amino acid pool lasts, muscle will not be catabolized.

Bearing this in mind I wonder if the increased nitrogen exretion in the second day of a fast could be coming from the free aminos, not muscle?
Also, I wonder what's happens to the rate of nitrogen excretion during the first day?

Stuart.

[Bo Bolund]

So I wonder how this ties in with the observation by Mike Eades that the 'free amino acid pool' lasts for up to 48 hrs (assuming of course that your last meal contained 'adequate' protein. In other words, while that free amino acid pool lasts, muscle will not be catabolized.

Bearing this in mind I wonder if the increased nitrogen exretion in the second day of a fast could be coming from the free aminos, not muscle?
Also, I wonder what's happens to the rate of nitrogen excretion during the first day?

Stuart.

The study I've posted is only a short term study on regular fasting. It does not study whether IF will prevent protein oxidation or not.

Nitrogen excretion during the first day can be read in the chart, but unfortunately there is no non-fasting value to compare with.

Has Mike Eades published a study or is it just a hypothesis?

[Stuart Mather]

.

Has Mike Eades published a study or is it just a hypothesis?

Bo, I must admit that I just assumed the 'free amino acid pool in fasted human body normally consuming adequate dietary protein lasting 48 hrs' was non-controversial basic nutritional biochemistry, not something that needed a 'study' to investigate it. The way he described it, it didn't seem hypothetical to me. But I could be wrong :) .

Stuart.