Your views on 'CARBOHYDRATES'

grinch031

What do you think gluconeogenesis is actually for? Do you think the liver converts protein and fat into glucose just for fun, while forcing the brain to run of ketones? As has been stated many times already in this thread, the body can generate all the glucose it needs from whatever food you eat. The brain is what needs glucose, the rest of the body can run (albeit very inefficiently) on ketones and fat. That's why it takes over 3 days of complete starvation before the brain even starts using ketones, because it's run out of stored food, and exhausted the majority of the glycogen supply, thereby forcing the brain to conserve what little glycogen is left, and use ketones to make up the difference.

Gluconeogenesis is required to ensure at least 25% of the brain's fuel comes from glucose. And because it takes several days to adapt to a ketogenic diet, gluconeogenesis will convert more protein into glucose until the brain adapts to using ketones. So it makes no difference whether you are in starvation or whether you are simply on a ketogenic diet. What matters is how many carbs and how much protein you eat as to how much gluconeogenesis needs to occur. So if you eat too much protein, then certainly you won't be fueling your brain with ketones.

Gluconeogenesis also converts fat into glucose, not just protein, so you'd need to cut back on everything to get gluconeogenesis to not happen.

I can't speak much for fat other than to say its highly inefficient to convert to glucose and the brain is still going to prefer ketones once they are readily available. Carb intake is most important followed by protein intake. There are plenty of endurance athletes on ketogenic diets and if what you say is true, they would all have no muscle left. They intentionally eat only moderate amounts of protein as to keep themselves in ketosis and avoid too much gluconeogenesis.

tigersword

Gluconeogenesis doesn't cancel out ketosis. They are separate metabolic activities. Gluconeogenesis only creates enough glucose to power the brain and control blood glucose, it does not replenish glycogen stores, so the rest of the body is still running on fat and ketones.

davidlbass

Love my carbs. I just count calories.

Wayne092

So.....do I eat spaghetti or not? I really don't know.

grinch031

Gluconeogenesis doesn't cancel out ketosis. They are separate metabolic activities. Gluconeogenesis only creates enough glucose to power the brain and control blood glucose, it does not replenish glycogen stores, so the rest of the body is still running on fat and ketones.

The only thing I'm really trying to suggest you are wrong about is that the brain isn't fueled by ketones when the person consumes adequate calories. Ketones will fulfill up to 75% of the brain's fuel requirements as long as 1) carb intake is low and 2) protein intake is low to moderate. Whether you are in starvation or not doesn't matter.