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Query Regarding Cognition and Ketone/Carb Restricted Diets

Hey, i’ve been searching for an answer for quite some time to my little scenario. I’m not overly eloquent at explaining it, but here goes.

So, neurons require primarily glucose for energy (average brain consumed 120g/glucose per day for regular function). Neurons can also use ketones, however they can not use oxidized fats/proteins. like other body parts can for energy

So, diet option #1

I have read that a carb-restricted diet (say, 50g per day) can lead to an impairment in your mental function. This happens because you’re not carb-depleted enough to be in a state of steady-state production of ketones, however your brain is under-supplied with energy (glucose), which can lead to cognitive dysfunction.

First question --> Is this true? Would diet option #1 leave your brain lacking in energy?

Obviously, if you consume plenty of carbs (say, 200g a day) you will have no mental function disruption. We’ll call this diet #2 --> plenty of carbs

Diet option #3
Very, very low carbs (less than 30g per day). I’ve heard that you’re so carb-depleted that your body goes into a full state of ketosis, and your brain is able to use ketones for energy. Since there is a bountiful supply, you have no cognitive dysfunction.
Next question --> Is this true? Would being in a state of ketosis leave your brain with AS MUCH energy as having 200g of carbs a day?

Basically, if your first priority is for cognitive function, which statement is true for mental performance?

High carbs > ketosis > 50g carbs
High carbs = ketosis > 50g carbs
high carbs = ketosis = 50g carbs (i.e it really doesn’t matter)
? <-- Which combination is going to ensure the optimal mental performance?

Cheers for reading

No one ever replies to my posts.
I’m off to stomp my feet and get grumpy