Similar to muscle memory, your body develops a "metabolic memory." Repeated periods of ketosis make your system more efficient at fat oxidation, allowing for quicker adaptation, fewer side effects, and greater benefits during subsequent ketogenic phases.
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Adding Medium-Chain Triglyceride (MCT) oil to exogenous ketone supplements (like BHB salts or esters) leads to a higher and more prolonged elevation of blood ketone levels than taking either substance alone. The MCT oil slows the absorption of the supplemental ketones, extending their effect.
Ferriss notes significant physiological changes while in ketosis, including needing 2-3 fewer hours of sleep and at least doubling his breath-hold time. He also experiences a dramatic reduction in ruminative thoughts, improving mental clarity and sleep onset.
While short-term keto adaptation (first month) may show no power gains, long-term adaptation (6-18 months) trains muscles to efficiently use fat as fuel. This results in significant power increases, with studies on soldiers showing up to a 50% improvement over their non-keto counterparts.
The goal of fiber is to feed gut bacteria that produce butyrate, a key acid for gut health. However, you can bypass this. Being in a ketogenic state directly provides beta-hydroxybutyrate (a ketone) to the gut, strengthening the microbiome without requiring high fiber intake.
Adopting a daily intermittent fasting routine before starting a ketogenic diet can eliminate the difficult 'keto flu' adaptation period. Fasting trains your body's metabolic machinery to use fat, making the switch to full ketosis much smoother and without energy dips.
After becoming fat-adapted on a ketogenic diet, strategically inserting 1-2 days of high-protein, low-fat meals (e.g., lean protein and vegetables) can rapidly increase fat mobilization from your body's stores, leading to accelerated fat loss.
The anxiolytic effect of ketosis has a clear neurochemical basis. Elevated ketones increase the levels of the enzyme GAD (glutamic acid decarboxylase), which converts the brain's primary excitatory neurotransmitter, glutamate, into its primary inhibitory (calming) neurotransmitter, GABA, creating a more stable neurological state.
Low measured ketone levels on a strict ketogenic diet may not be a failure. It can signify high metabolic fitness, where your body is so efficient at utilizing ketones for energy that fewer are left circulating in the blood to be measured, creating a false negative.
Ketones are a more efficient energy source than glucose, producing less metabolic “trash” (oxidative stress). Crucially, they can penetrate the blood-brain barrier and fuel brain cells even when they've become resistant to insulin, directly combating cognitive decline and brain fog.
The time required to enter ketosis varies dramatically. A healthy person might take a few days, but someone with years of high insulin resistance could need over two weeks of strict low-carb dieting to deplete their massive glycogen stores and begin producing ketones. This manages expectations and prevents premature failure.