Noooo I got a question wrong on UWorld because I didn't read the comments to see the correction that protein was 4! Lol, at least now I will DEFINITELY remember for test day.
Great video! 1 small correction - First Aid 2021 has protein as 4 kcal per gram (as opposed to 7 as shown in the video). Ethanol has 7 kcal per gram (7 letters in "ethanol").
Why are ketone bodies not involved in the graph of metabolic fuel utilization? I mean what is the timeline for KB? Wouldn't ketogenesis occur in the liver during prolonged starvation and then break down to get acetyl Coa which enters TCA cycle to provide ATP ? The use of ketone bodies will reduce the use of amino acids for gluconeogenesis, hence preserving protein for survival.
The TCA cycle essentially stops if you are truly Keto because you have low glucose and your body will use up resources until TCA can't run. Then it directs Acetyl-CoA down the ketone production line. That takes a little time which is why you tend to go through that "Keto flu" on day 2-3. Once you are burning fat (which he claims here is at 3 days) then you should be eating a diet that is +70% fat. No sugar and very low carbs will keep the TCA cycle starved and ketone production up. This video is about starving so he goes from ketosis to the next phase; breakdown of your body which might happen to an anorexic/bulimic person. That is beyond the stage of ketosis. What we do on Keto diet is enter ketosis after about 3 days and maintain it by eating high fat diet. Too much protein will actually turn up gluconeogenesis and then kick you out of ketosis. Common mistake keto dieters make is too much protein. Obviously you don't want too little so this is why that tends to happen. People recommend different daily amounts of protein depending on exercise, age, size ect. You have to figure out your own number. The graph he shows is labeled Fat or fatty acid. Those are the precursors to ketones. Maybe that is part of the confusion but the graph is showing stores and what you use up as time goes on through starvation. The red line is fatty acids which break down into ketones. Once the fat is all gone you start breaking down your own organs. So you never want to run out of fat completely. I went Keto and went from obese to normal in 4 months. I eat sugary stuff 4 times per year, no grains. Fresh veggies and meat (preferably fish) but no potatoes. Look up Keto / IF
This is a great video! But, brain is actually highly dependant on glucose, but after 3-7 days, since there is no glucose and the primary energy source is fatty acids, the body starts generating more ketones since brain cannot utilise free fatty acids. This is why it’s highly dependent on ketones, but doesn’t mean that it is always dependent on ketones. I wanted to clarify this :) Thank you very much for your time and thank you for this great video.
This is only really accurate within a human organism that is 1) carbohydrate dominant in diet, and 2) does not have sufficient adiposity to sustain mitochondrial ATP production. Although this will undoubtedly help one pass the tests.
For some reason I found myself wanting to try this out - go 3 days without eating so I could say I have no glycogen left and am running solely on beta oxidation. But then I got to the part of the video where you said at 1 week you literally start dying, and I changed my mind 😂
This is where this series should begin. This is how your body uses the food you eat to produce the energy to that keeps you alive. Sugar/starches, fats (lipids), and finally (if it needs to go that far) proteins.
Be careful not to select lactate as a substrate used for energy for the brain. Brain only uses glucose or ketone bodies. So if glut 1 deff is present ketones will provide the energy as lactate and alanine converting to glucose cannot be used. I was confused on this at first.
TheShot Doctorr the BLaH mnemonic where brain relies on lactate and alanine really means brains relies on liver to convert lactate and alanine to pyruvate and glucose. BRAIN then uses glucose as energy source for days 1-3. I came across a question asking for fuel source of brain that had glucose and lactate as answer choices and remembered “brain relies on lactate and alanine” I got it wrong because brain can only utilize glucose and ketones. LIVER converts lactate and alanine to glucose
How do you explain people doing 30 day fast “no food” if after one week your body doesn’t use fat anymore? It does not make any sense when there is so much research that shows that literally your body never kills itself. I can’t believe you are saying this to people without consideration of all doctors research and people doing their own personal experiments and research and they all show that the body heals itself.
