Nutrition & gut
Fuel, metabolism and the 38-trillion-microbe ecosystem that shapes how you feel, sleep and age.
Metabolic health is the substrate everything else runs on. Continuous glucose monitoring (Levels, Dexcom, Abbott) turns post-meal glucose variability into a daily recovery signal; HbA1c and fasting insulin are the headline clinical markers (Johnson: 4.9% and 2.6 μIU/mL). NAD+ availability and mitochondrial proxies — VO₂max, lactate threshold, resting HR — round out cellular energy. The open research question is whether Arete's thermal protocols measurably improve insulin sensitivity over a membership.
What we track
| Marker | Captures | Target |
|---|---|---|
| CGM glucose | Post-meal variability — a daily recovery predictor | Low, stable excursions |
| HbA1c | Three-month glycaemic average | <5.0% |
| Fasting insulin | Insulin sensitivity | <5 μIU/mL |
| NAD+ | Cellular energy currency | Maintained for age |
Post-meal glucose as a recovery signal
Continuous glucose monitoring turns metabolism into a daily readout: the size and shape of the curve after a meal predicts how recovered — and how metabolically flexible — a member is. It is the fastest-moving window we have into cellular energy.
Mitochondrial function, without a biopsy
VO₂max, lactate threshold and resting heart rate together proxy mitochondrial health. The open question for the house: do infrared-sauna protocols measurably improve insulin sensitivity across a membership?
The enteric nervous system runs ~500 million neurons along the GI tract — more than the spinal cord — and can run digestion autonomously. ~90% of the body's serotonin is produced in the gut, regulated directly by the microbiome.
Four communication channels
| Channel | Mechanism | Significance |
|---|---|---|
| Vagus nerve | 80% afferent (gut → brain); signals fullness, nutrients, bacterial activity | The primary route — severing it removes most microbiome behavioural effects |
| HPA axis + gut barrier | Chronic cortisol damages tight junctions; LPS leaks into blood | Vicious cycle: stress → leaky gut → inflammation → more stress |
| Microbial metabolites | Bacteria produce SCFAs (esp. butyrate), absorbed systemically | Direct brain effects via blood-brain-barrier crossing |
| Immune signalling | ~70% of immune cells live in the gut; microbiome shapes cytokines | Connects the microbiome directly to inflammaging |