Most conversations about diet and longevity focus on calories, macros, and generic advice.
This one was different.

When Dr. Peter Attia sat down with Dr. Dom D’Agostino — a leading researcher in metabolic therapy, brain energetics, and hyperbaric oxygen — the conversation peeled back the curtain on how human metabolism actually works, and why so many people feel tired, foggy, inflamed or stuck.

And the biggest takeaway?

👉 Most of us are running on a broken energy system, and ketosis — even occasionally — can reset it.

Below is a science-based but simple breakdown of what you really need to know, and the actionable changes that matter.

🔥 1. Ketosis Isn’t a "Diet" — It’s an Energy State Your Body Already Knows How to Use

Dom explains the simplest way to understand ketosis:

When insulin is low (through fasting or carbs dropping), your liver switches fuels and begins producing ketones — clean-burning molecules that:

• fuel the brain when glucose is low

• reduce inflammation

• stabilize neurons

• improve metabolic efficiency

• support cognitive function

• extend endurance and resilience

This is why fasting, low-carb eating, or supplemental ketones can make people feel:

• mentally sharp

• less hungry

• calmer

• more resistant to stress

✔ Key point:
You don’t have to live in ketosis — but having access to it as a metabolic gear is incredibly beneficial.

🔬 2. Why Ketones Improve the Brain (Even If You Eat Carbs)

The brain of someone with metabolic stress — fatigue, insulin resistance, inflammation, or cognitive decline — often struggles to use glucose efficiently.

Attia highlights this in Alzheimer’s research:
👉 A failing brain can’t use glucose, but it can still use ketones.

Dom’s lab has repeatedly shown that ketones:

• restore fuel to brain cells

• reduce excitotoxicity

• improve mitochondrial function

• calm hyperactivity in neurons

• lower seizure activity

• enhance focus and productivity

You don’t have to go full keto to get the effect — even low levels of ketones from:

• overnight fasting

• 1–2 keto meals a day

• exercise

• exogenous ketones

…can meaningfully improve cognitive performance.

🧪 3. Exogenous Ketones: The Good, the Bad, and the Misunderstood

Dom has been central to developing modern ketone esters, salts, and metabolic supplements.

Here’s the simplified version:

Ketone Esters

• Very powerful

• Spike ketones rapidly

• Useful for research, elite performance, or medical contexts

• BUT can cause nausea, hypoglycemia, insulin spikes, or overstimulation in normal users

Ketone Salts

• Gentler & easier to tolerate

• Provide steadier ketone levels

• Deliver electrolytes your body loses early in ketosis

• Much safer for beginners

Why use exogenous ketones at all?

Attia & D’Agostino agree they can be helpful for:

• boosting mental performance

• easing transition into a low-carb diet

• appetite control

• fasting support

• workouts requiring focus

• neurological performance

But the real power comes when they are paired with a lifestyle that supports metabolic flexibility — not used as a shortcut.

🍽️ 4. Why Ketogenic Diets Help With Weight Loss (Even When Calories Matter)

Attia is blunt:
“You still have to be in a caloric deficit.”

But Dom reveals why keto works so well for creating that deficit:

✔ Ketosis reduces hunger

Ketones blunt appetite hormones and stabilize energy.

✔ Higher protein = more satiety

Most successful “keto” diets today aren’t 90% fat — they’re high protein, moderate fat, which is ideal for body composition.

✔ Keto removes hyper-palatable foods

When you eliminate sugar + processed foods, overeating becomes harder.

✔ Glucose and insulin stabilize

This shifts energy from storage mode → burning mode.

🧠 5. Ketosis for the Brain: Alzheimer's, Concussions, and TBI

Two massive insights:

Aging brains lose the ability to use glucose — but keep their ability to use ketones.

This is why ketogenic interventions are being tested for:

• Alzheimer’s

• Mild cognitive impairment (MCI)

• Parkinson’s

• Dementia

• TBI

• Post-concussion recovery
  

Dom notes promising early findings:
Even patients with severe cognitive decline often experience acute cognitive improvement when ketone availability increases.

If you have a parent or family member experiencing cognitive decline, ketone availability (dietary or supplemental) may provide measurable benefit.

⚡ 6. Cancer Metabolism: What Almost No One Understands

Dom is careful but clear:

✔ Cancer cells depend heavily on glucose and glutamine.
✔ Ketosis lowers glucose availability and insulin — reducing a key growth pathway.
✔ Therapeutic ketosis may enhance certain cancer therapies.

This is NOT a cure.
But in glyoblastoma, metastatic cancers, and metabolic tumors, ketosis combined with standard of care extends survival in early trials.

Attia stresses:
We need much bigger clinical trials — but the metabolic approach is scientifically sound.

🫁 7. Hyperbaric Oxygen Therapy: Overhyped or Underrated?

Dom’s career began in Navy research studying oxygen toxicity.

Today, hyperbaric oxygen is being explored for:

• concussions

• PTSD

• cognitive decline

• wound healing

• brain inflammation

Dom believes:
👉 For acute concussion (first 48–72 hours), HBOT may be one of the most effective interventions.

For chronic brain injury, the results are mixed but promising when protocols are correct.

💊 **8. SPECIAL SECTION — Matt’s Request:

What Do Peter Attia & Dom D’Agostino Think About NAD?**

NAD is one of the most talked-about “longevity supplements.”

Here’s their combined take — simplified.

Peter Attia:

⚠️ Skeptical. Not convinced. Doesn’t personally recommend.

• NAD boosters like NR/NMN raise blood NAD but may not raise mitochondrial NAD (where it matters).

• Human longevity outcomes? Weak or nonexistent.

• Better ways to raise NAD naturally:
  

  • exercise

  • fasting

  • ketosis

  • metabolic health

He sees NAD as promising but not proven — and not a priority supplement.

Dom D’Agostino:

⚠️ More optimistic — but only in specific contexts.

Dom believes stabilized NAD molecules (not standard NR/NMN) may help in:

• traumatic brain injury

• metabolic stress

• mitochondrial dysfunction

• aging athletes

• neuroprotection

Dom is currently researching next-generation NAD compounds combined with ketones.
He does not suggest everyday people rely on over-the-counter NAD boosters for longevity.

So Should You Take NAD? (Simple Answer)

Helpful For:

• older adults (>55)

• neurological recovery

• metabolic dysfunction

• extreme endurance athletes

• chronic inflammation

Probably Not Helpful For:

• healthy young or middle-aged adults

• those expecting anti-aging miracles

• anyone not already optimizing sleep, protein, exercise, glucose

The safer takeaway:

➤ Before supplementing NAD, raise NAD naturally with exercise, fasting, ketones, and mitochondrial health.

✅ ACTIONABLE TAKEAWAYS (For Everyday Life)

If you do nothing else, do these 6 things:

1. Increase Morning Ketones Naturally

Try one of the following:

• 12–14 hr overnight fast

• morning workout before eating

• low-carb breakfast or skip breakfast

• coffee + MCT oil for focus

2. Keep Protein High

Aim for:

• 0.7–1g protein per lb of target bodyweight
  Build meals around protein first → everything improves.

3. Add Occasional Ketosis

Not forever — just as a tool.
Try:

• 2–3 days/week low-carb

• 1 24-hr fast weekly

• keto breakfast, normal dinner

• exogenous ketones for work/focus sessions

4. Support Your Brain

• Omega-3s

• B vitamins

• Sleep 7–9 hours

• Keep blood sugar stable

• Reduce chronic inflammation

5. Avoid “energy toxicity”

More ketones ≠ better.
Stay in the 1.0–2.0 mmol range if supplementing.

6. Improve Metabolic Flexibility

Your body should be able to run on both glucose and ketones.
This is the foundation of longevity.

🌟 FINAL WORD

You don’t need to be keto.
You don’t need to take NAD.
You don’t need to fast for days.

But you do need a flexible metabolism — because metabolic inflexibility is the root of fatigue, accelerated aging, inflammation, and cognitive decline.

Ketosis is one of the most powerful tools we have to rebuild metabolic resilience.
Even small, manageable shifts can fundamentally change your health trajectory.

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