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How to Use Ketosis for Enhanced Mood, Cognition, and Long-Term Brain Protection — A Practical and Tactical Guide with Dr. Dominic D'Agostino (Plus: Deconstructing Tim's Latest Keto Experiment) (#845)

2026-01-07 - source - Read full transcript

Tim Ferriss (host)Dominic D'Agostino

Key insights

Ketosis appears to quiet the brain by elevating GABA and lowering glutamate, which D'Agostino says underlies its rapidly expanding use in 'metabolic psychiatry' for depression, bipolar disorder, schizophrenia, and anxiety.

He ties this to the ketogenic diet's long-established anti-seizure mechanism (effective across temporal lobe epilepsy, Lennox-Gastaut, and Dravet syndrome regardless of cause) and notes the field is now largely funded by the Baszucki Group. He frames it as a gentler route to the same GABAergic calming people otherwise seek from alcohol or benzodiazepines.

brain-and-mental-health

Beta-hydroxybutyrate stimulates the adaptive immune response and starves glycolytic pathogens, which is D'Agostino's working explanation for why strict ketosis resolved Ferriss's cognitive symptoms from a second Lyme disease infection.

He notes the Borrelia spirochete is essentially 100 percent glycolytic, so limiting glucose availability targets its energy supply directly, while elevated BHB separately boosts adaptive immunity (an effect now being explored in CAR-T and checkpoint-inhibitor cancer therapy at University of Pennsylvania). He says he has heard similar reports from patients with shingles and herpes simplex.

ketogenic-metabolism

Ketosis is not a cancer cure, but it slows growth in the roughly 80 percent of cancers that are highly glycolytic and enhances the response to standard radiation, chemo, and immune-based therapies.

D'Agostino says the right protocol depends on the patient's body composition: overweight patients (BMI ~28-32) do better with a calorie-restricted ketogenic diet or fasting, while leaner patients (BMI ~20-22) need a weight-maintaining, eucaloric approach so they still get anti-inflammatory and neuroprotective benefits from elevated ketones without further weight loss.

ketogenic-metabolism

The metabolic adaptations built during extended ketosis behave like 'muscle memory' - largely driven by increased mitochondrial number and capacity - and can be reactivated quickly even after time off the diet.

D'Agostino compares it to detraining and retraining: someone who built a 400-pound bench press and takes months off can only lift 225 at first but regains most of their strength in two to three months, far faster than the original 10 years it took to build. He argues the same 'metabolic memory' applies to fat-oxidation enzymes and mitochondrial density from prior ketogenic periods.

ketogenic-metabolism

Chronic, high-dose use of 1,3-butanediol-based exogenous ketone esters and monoesters can damage the liver in ways that don't show up on standard blood panels.

D'Agostino's lab found that animals dosed chronically with 1,3-butanediol-based ketone esters showed normal transaminases (ALT/AST) but had visible liver damage on necropsy - inflammation, sinusoidal dilation, and fatty changes - because metabolizing the compound via alcohol and aldehyde dehydrogenase depletes hepatic NAD and ATP. He says older adults are especially vulnerable, since alcohol-metabolizing capacity drops to roughly 20-30 percent of a young adult's by age 80.

exogenous-ketones-safety

1,3-butanediol, the molecular backbone of most commercial ketone esters, is metabolized almost identically to ethanol and can intoxicate, create dependence, and cause alcohol-like withdrawal.

D'Agostino recounts making '1,3-butanediol jello shots' with chemist Patrick Arnold before ketone esters existed and says the compound has documented narcotic effects and withdrawal in animal studies. Ferriss corroborates with a personal story of becoming visibly intoxicated ('I did not do this risk assessment properly') after a single six-to-eight-ounce dose intended as a sober alcohol substitute.

exogenous-ketones-safety

Ketone esters can paradoxically suppress a person's own ketone production by spiking insulin, while ketone salts raising blood ketones to the same level do not trigger that spike.

D'Agostino explains that a rapid rise in blood ketones from an ester dose can double or triple insulin, which shuts off endogenous ketogenesis and can leave someone briefly hypoketotic and hypoglycemic - an energy deficit in the brain. He lays out four criteria for choosing any exogenous ketone: palatability, tolerability, pharmacokinetics (how gradually it rises and falls), and toxicity.

exogenous-ketones-safety

A low blood or breath ketone reading does not necessarily mean someone isn't in ketosis - well-adapted, insulin-sensitive people can have such high ketone utilization that production outpaces what shows up in blood.

D'Agostino says ketone concentration in blood reflects production minus utilization, and metabolically fit subjects (whether rodents or elite athletes) dispose of ketones two to five times faster than sedentary ones, especially in a caloric deficit. In his own paired testing with Peter Attia, blood ketones stayed low during deep fasting while breath acetone maxed out the meter, leading him to consider breath ketones the more reliable indicator under caloric restriction.

biomarker-tracking

The Glucose Ketone Index (glucose in mmol/L divided by ketones in mmol/L) is a more clinically useful single number than either glucose or ketones alone, and D'Agostino considers a GKI of 1-4 - not the stricter 1-2 some researchers push - to be therapeutic across cancer, seizure, and other applications.

He notes this is a point of active disagreement with Thomas Seyfried and the Society for Integrative Metabolic Oncology, who advocate for the tighter 1-2 range. He adds that reaching a GKI even in the 5-10 range would be nearly impossible for most people without medical-grade fasting, and that a GKI of 1 corresponds to roughly 10 percent of the brain's available energy coming from ketones.

biomarker-tracking

High-fat, high-fiber, high-salt meals slow gastric emptying long enough to blunt the insulin and gluconeogenesis response that can otherwise knock someone out of ketosis, and a short walk right after a large meal further blunts any glucose spike.

D'Agostino explains the pyloric sphincter stays closed until stomach contents become isotonic, which delays amino acids (the main driver of gluconeogenesis) from entering the bloodstream; MCT oil and insoluble fiber extend this further. He adds that even a 10-20 minute brisk walk right after eating activates insulin-independent GLUT4 glucose uptake and burns off some of the sympathetic-nervous-system glucose mobilization triggered by a stretched stomach - but the walk should happen immediately, not 60-90 minutes later once the spike has already occurred.

practical-keto-protocol

For someone with a family history of neurodegenerative and cardiovascular disease who doesn't want to stay in ketosis year-round, D'Agostino's recommended minimum effective dose is a low-carb (roughly under 100g/day) Mediterranean-style baseline most of the time, with periodic one-week resets into deeper ketosis (GKI of 1-2 for at least three days).

He argues the benefits of each reset - including measurable autophagy markers - appear to carry over for about three weeks, which is why he favors a repeating 'three weeks of benefit, one week of reset' cadence over doing several contiguous weeks of keto followed by a long break. He suggests front-loading each reset week with roughly 50 percent calorie restriction for the first two days to accelerate the ramp into ketosis.

practical-keto-protocol

D'Agostino considers optimizing a cluster of cardiometabolic and inflammatory biomarkers - insulin, high-sensitivity CRP, the omega-3-to-6 ratio, B12, and magnesium - alongside exercise and tracked body composition to be the strongest available lever for delaying Alzheimer's onset.

He specifically flags hsCRP as possibly more predictive of atherosclerotic risk than LDL cholesterol, and notes that B12 deficiency alone can cause brain atrophy that presents as Alzheimer's and is reversible with correction. He frames muscle as an 'endocrine organ' tightly linked to brain size and recommends annual DEXA scans, partly as a compliance and accountability tool.

brain-and-mental-health

Books referenced

Spark: The Revolutionary New Science of Exercise and the Brain - John J. Ratey - Ferriss points listeners to it (calling it outdated but still useful) when discussing exercise, BDNF, and klotho as brain-protective levers.
The 4-Hour Body - Tim Ferriss - Ferriss references his own book twice - once for readers who lost more body fat than expected on similar protocols, once for its coverage of GLUT4.

Media referenced

Alone - show - Ferriss cites the survival show (seasons six and seven especially) to set up his question about 'rabbit starvation' and whether a low-fat, high-protein keto diet is sustainable.
Diary of a CEO - podcast - D'Agostino notes Dr. Annette Bosworth ('Dr. Boz'), who popularized sardine fasting, has appeared on it.
The Metabolic Link Podcast - podcast - D'Agostino's own podcast, mentioned as one of his main outlets alongside ketonutrition.org and the Metabolic Health Initiative education platform.

Companies

Baszucki Group - Funds much of the rapidly expanding metabolic-psychiatry research applying ketosis to depression, bipolar disorder, schizophrenia, and anxiety.
Medifoodz - New prescription whole-food ketogenic meal company D'Agostino was testing and was impressed by; he sees it as proof a doctor-prescribed, whole-food keto meal service is finally viable.
Quest Nutrition - Cited as an earlier attempt at whole-food-style ketogenic products that lost momentum after a CEO change.
Keto's Therapy - D'Agostino's wife's company, which sells ketone salts; Ferriss says it's the exogenous ketone product he uses most consistently.
Society for Integrative Metabolic Oncology - Group D'Agostino works with (alongside researcher Thomas Seyfried) on standardizing the Glucose Ketone Index for cancer metabolic therapy.
Dexcom - Continuous glucose monitor D'Agostino prefers over Abbott's because it can be user-calibrated against a blood reading; Ferriss also wears one (G7) during his experiment.
Keto-Mojo - Finger-prick glucose/ketone meter both men use and reference throughout for calculating the Glucose Ketone Index.

Techniques and frameworks

Ketogenic diet / nutritional ketosis - Core protocol discussed throughout: high fat, moderate protein, under ~20g carbs/day, used for mood stabilization, weight loss, and metabolic therapy.
Time-restricted feeding / intermittent fasting - Ferriss's ~16-hour daily fasting window (eating roughly 2-9pm), which he credits with making his transition into ketosis symptom-free this time.
Glucose Ketone Index (GKI) - Blood glucose (mmol/L) divided by blood ketones (mmol/L); the two discuss target ranges (1-2 vs. 1-4) for therapeutic ketosis and how to estimate it without lab-grade calibration.
Cyclical ketogenic diet - Ferriss describes his 1990s protocol of ~6 days keto plus a glycogen-depletion and carb-reload day, used originally for mood stabilization while building muscle.
Fasting-mimicking diet - Valter Longo's ~5-day, ~600-calorie, plant-based low-protein protocol; cited as evidence that short fasting periods can shift cardiometabolic biomarkers for months afterward.
Protein-veggie day cycling - D'Agostino's own technique of periodically doubling protein intake for one to two days (dropping out of ketosis) to accelerate body-fat loss, then cycling back into strict keto.
Sardine fasting - Credited to Dr. Annette Bosworth ('Dr. Boz'), who amplified an idea D'Agostino originated; referenced as a prior-episode topic, not detailed again here.

Summary

Tim Ferriss opens this episode 18 days into a strict ketogenic diet and uses the conversation with longtime collaborator Dr. Dominic D'Agostino, a University of South Florida researcher and one of the field's leading exogenous-ketone scientists, to work through both the underlying science and his own confusing biomarker data in real time. The two start with the established and emerging benefits of ketosis: its calming effect on the brain via elevated GABA and lowered glutamate, its role in "metabolic psychiatry" for conditions from depression to schizophrenia, and its more nuanced application in oncology, where it slows glycolytic tumors and augments standard treatment without being a cure. Ferriss shares his own history of resolving severe post-Lyme-disease cognitive symptoms through strict ketosis, and D'Agostino offers a mechanistic theory involving both starving the glycolytic Borrelia spirochete and BHB's effect on adaptive immunity.

A large portion of the conversation is a detailed, practical troubleshooting session: Ferriss's continuous glucose and ketone monitors are showing readings that suggest he is barely in ketosis, despite feeling sharp and symptom-free. D'Agostino walks through why this is likely a "false negative" - his months of intermittent fasting have made him so insulin-sensitive and efficient at ketone utilization that his tissues are consuming ketones nearly as fast as his liver produces them, making blood readings misleadingly low. This leads into a broader discussion of the Glucose Ketone Index (GKI) as a more useful composite metric than either number alone, disagreements within the field over the optimal target range (D'Agostino favors 1-4 over a stricter 1-2), and the practical mechanics of gastric emptying, fat/fiber/salt as buffers against gluconeogenesis, and post-meal walks as a way to blunt glucose spikes.

The two spend significant time on exogenous ketones, an area where D'Agostino has direct commercial and research interests he explicitly discloses. He lays out a clear framework - palatability, tolerability, pharmacokinetics, and toxicity - for evaluating any ketone supplement, and is notably blunt about the risks of 1,3-butanediol, the alcohol-derived backbone of most ketone esters and monoesters: chronic high-dose use causes liver changes invisible to standard blood panels, and the compound itself is metabolized like ethanol, capable of causing intoxication, dependence, and withdrawal. Both men share personal anecdotes of accidental over-intoxication, and D'Agostino argues the exogenous-ketone industry should be shifting toward ketone salts and non-butanediol formulations, particularly for older or more vulnerable users.

The conversation closes on prevention and long-term protocol design. D'Agostino recommends a low-carb, Mediterranean-style baseline diet for most of the year, punctuated by periodic one-week resets into deeper therapeutic ketosis (GKI of 1-2), arguing that the metabolic and autophagy benefits of each reset appear to persist for roughly three weeks. He frames Alzheimer's prevention less as a single dietary intervention and more as a biomarker-optimization project spanning insulin, inflammation (hsCRP), omega-3 status, B12, exercise, and tracked body composition. The episode ends with lighter tangents - mackerel as a nearly free keto staple, a new prescription whole-food keto meal company (Medifoodz) D'Agostino is testing, and a startling story about D'Agostino and his wife being accidentally dosed by adulterated theanine gummies bought at a retail store.

Notable Quotes

"The ketogenic diet just quiets the brain, lowers glutamate, and elevates GABA, a brain stabilizing, calming neurotransmitter. And that's why people gravitate towards alcohol, right?" - Dominic D'Agostino

"It's not a cure for cancer, and I cringe when people talk about that like online, the ketogenic diet curing cancer, it does slow it down, especially if it's highly glycolytic, which 80 percent of cancers are." - Dominic D'Agostino

"I'm not totally convinced that those benefits are going to span that amount of timeframe... So you get benefits for three weeks, reset one week, benefits for three weeks, reset one week." - Dominic D'Agostino

"30 milliliters of 1,3-Butanediol is kind of like 30 milliliters of ethanol." - Dominic D'Agostino

"It's like your Leydig cells are pretty smart. That's the reason your balls turn into Raisinets is because it's like, 'Cool, we don't have to make that anymore.'" - Tim Ferriss