Quote:
Originally Posted by CallmeAnn
Here is the link.
http://healthyforkswellness.com/art...-insulin-spike/
I know there are tons of vegan writers who bash meat but this is a concrete claim that it actually raises insulin more than sugar. What with Dr. Fung stating that Diabetes is a case of elevated insulin, rather than bg, this got my attention. I know that the rise in bg is a marker for insulin spikes but it's just such a weird claim. Not that I'm worried, but outright lying seems so strange.
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Insulin spike doesn't tell us anything useful. That's because we don't lose or gain fat during a meal, instead we lose or gain fat in-between meals. The higher the fasting insulin, the slower fat is released; the lower the fasting insulin, the faster fat is released. So, the more pertinent question is what foods cause fasting insulin to stay higher/lower?
If we look at insulin spike, we have to understand what insulin does during that spike. For example, if the spike was caused by carbs, then those carbs will do something different than if the spike was caused by protein. Gary Taubes often explains that when fat cells take in glucose, it gets converted to glycerol, and this glycerol binds to fatty acids to make triglycerides. Triglycerides are too big to go through the fat cell wall, so they're stuck inside. Now if the spike was caused by protein, there's no glucose to convert to glycerol.
We currently believe that protein causes BG to rise because protein gets converted to glucose, but that's a misunderstanding. Dietary protein is not converted to glucose, it's used to build/repair/maintain enzymes and tissues. There's no glucose in protein, so if BG does rise, where does the glucose come from? Well, it comes from the glycogen stored in the liver or other cells, and from glycerol stored as triglycerides stored in fat cells. It can't come from anywhere else.
In fact, insulin inhibits gluconeogenesis, it prevents the production of new glucose in the liver, it prevents the conversion of other substrates into glucose, such as protein-to-glucose (actually only some amino acids, not all of them). And, insulin stimulates proteosynthesis and inhibits proteolysis. So, dietary protein (some amino acids) is not converted to glucose, and dietary protein is pushed by insulin toward new protein production and new tissue production and repair/maintenance.
OK, so protein causes insulin to spike, and insulin causes BG to drop, so we should expect BG to drop, right? But if we see BG rise instead, then protein must have some other effect elsewhere on stored glucose to release it to compensate for the insulin spike. One such effect is on glucagon, which acts on the liver to convert glycogen to glucose, then dump it into the bloodstream, causing BG to rise. There's still the same total amount of glucose, but some of it just shifted from the liver to the bloodstream. Eventually it's gonna shift back to the liver as glucagon drops once there's no need for it anymore. It's gonna shift back also because insulin pushes glucose into the liver, and there's a bit more insulin due to protein. If it's just protein, we haven't changed total glucose or total fat, so once that protein is fully integrated into enzymes and tissues, it's gonna have virtually no effect on stored glucose, BG, and stored fat. But then, since it's only protein, and integration takes time, some of that glucose and fat will invariably be used for fuel during that time, net result is less glucose and less fat.
Now if instead we eat carbs, the whole thing changes. Total glucose goes up, so total insulin must go up to keep BG normal, i.e. to keep stored glucose from leaking out of the liver and from fat cells. Can't convert glucose to protein, and we didn't eat protein, there's a protein deficit, total protein drops. But, insulin also inhibits proteolysis (the breakdown of protein), and there's a bit more insulin to keep BG normal, so this extra insulin compensates somewhat for the dietary protein deficit, it slows down protein losses. There's still a total protein deficit, so overall protein metabolism or even overall metabolism of everything slows down too. Additionally, insulin keeps fat inside fat cells, and there is a bit more insulin to keep BG normal, so this extra insulin slows down fat release, this further slows down overall metabolism of everything. If you think about it, this is actually a good thing because if we keep metabolism up, and there's a protein deficit, protein loss is going to be greater than otherwise, that protein deficit is going to be felt much quicker. Things have to slow down when there's a deficit.
So, between protein and carbs, regardless of the insulin spike, the one most likely to allow fat loss or to allow normal metabolism is protein.
All the above is just how I see it, not necessarily how it actually works, so take it with a grain of salt. On the other hand, that thing with protein/insulin/gluconeogenesis/proteosynthesis is quite positively a sure thing, so we have to stop thinking dietary protein gets converted to glucose cuz it's obviously not true.