[49para]

Why would your body breakdown your organs when you still have plenty of adipose stores ?

Do you have a citation for the "starvation mode" ? If it's the 1940's study from MN, that was only when the subjects where well into single digit fat %.

[jacques_chester]

Bodies aren't finite state machines and the concept of "modes" can be misleading. What you have is a (very large) number of independent processes that have differing amounts of flow under different conditions.

So, for example, you don't click from building muscle to consuming muscle. What happens is that catabolism has a higher flow than anabolism, so the net balance is negative.

As the body becomes leaner in starvation conditions, processes that recover energy from gluconeogenesis or from lipolysis cannot produce "enough" energy. So feedback loops that suppress the breakdown of organ tissue weaken and eventually that loop shifts.

[jacques_chester]

Clarifying some of what I wrote above --

* "independent processes" is better described as "interdependent, oftentimes antagonistic processes".

* In describing net balance, the key is that both processes remain active throughout, even if only the net balance of flow can be observed. Or more likely, the integration of the net flow over time (the stock).

* I say "that loop shifts", more accurately the loop dominance shifts. This is a term from system dynamics for describing how the behaviour of the overall system can suddenly change due to a change in flow of one or more loops that are working antagonistically.

[throwaway_law]

>Why would your body breakdown your organs when you still have plenty of adipose stores ?

Most people are not "fat adapted" meaning their body/brain primarily run off of glucose.

When you fast and your body runs off of glucose, it still goes into ketosis and burns fat, but the brain still needs glucose because that its accustomed primary fuel source (think of marathon runners hitting the wall, that is their body conserving remaining glucose in the body for the brain to function). When their is no dietary glucose the body breaks down protein (muscle and organs) to convert into glucose to keep the brain working (gluconeogenesis).

This will still occur but to a far lesser degree to people who are fat adapted and primarily use fat for energy.

[pizza234]

This phenomenon (specifically, body breaking down muscles), is a very practical, and doesn't really need studies.

When doing bodybuilding (or sports in general), one can very easily measure their own bodyfat, and losing more muscle than fat is the enemy #1 during diet cycles (whose objective in fact is to minimize muscle loss and maximize fat loss).

Of course, "plenty of adipose stores" is relative. I guess that if one is 30% BF and never does any activity, as soon as they start to lift some weights, they'll put muscles and lose fat quickly for some time, independently of the calories deficit.

The other exception is when one takes anabolic steroids.

[dvt]

You can see that there was protein turnover just after 10 days in rats: https://www.ncbi.nlm.nih.gov/pubmed/7119891

In healthier rats, protein turnover (cannibalizing muscles / organs) was faster than in obese rats. I had some human studies bookmarked, I'll try to find them again. There were a few ketosis studies that discussed "starvation mode" so maybe try searching for that.

[ksaj]

> I had some human studies bookmarked, I'll try to find them again.

Please do. Rat studies are helpful, but not definitive-- close but not exact. That's why it takes so long for medicines and therapies that are shown to absolutely work on rats still take forever to reach humans.