Lab marker
HOMA-IR
Homeostatic Model Assessment for Insulin Resistance
A simple ratio of fasting insulin and glucose, the most widely used surrogate for insulin resistance outside of research settings.
What it measures
HOMA-IR = (fasting insulin μU/mL × fasting glucose mmol/L) / 22.5. A higher value indicates greater insulin resistance. Validated against gold-standard hyperinsulinaemic-euglycaemic clamp studies, though with substantial variability.
Reference context
3 guideline sources
Population norms vary by ethnicity and assay; cut-offs are best treated as guidelines rather than diagnostic thresholds. Trend over time on the same lab is more informative than a single value.
Population context: consult guideline targets below
Mechanism
Why moving this marker matters
By combining fasting glucose and insulin, HOMA-IR captures both pancreatic secretory load and tissue sensitivity in one number, useful when neither value alone is yet abnormal but the combination signals compensated resistance.
Guideline targets
What major guidelines recommend
Common reference (insulin sensitive)
<1.0
Common reference (early insulin resistance)
1.0–1.9
Common reference (significant resistance)
≥2.0
How to measure
The test, where to get it, when to repeat
Method
Calculated from a single fasting blood draw (both insulin and glucose).
Where
Compute from your fasting insulin + glucose values. Many private labs report HOMA-IR directly.
Typical cost
Free (computed); same panel as fasting insulin.
Fasting
Required
When to test
Common practice
Useful when investigating early insulin resistance; less helpful once diabetes is established.
Where to test
Independent labs offering this test
Healicus refers you to independent laboratories. You order from the lab; they take the sample, run it, and return your result on their own platform. Healicus never sees your value.
Randox Health
UK · EU · INTLClinic-based premium panels — wider biomarker breadth than home-test brands.
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Medichecks
UKUKAS-accredited home blood-test panels with GP-equivalent biomarker coverage.
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Context
Reading the numbers
Population norms vary by ethnicity and assay; cut-offs are best treated as guidelines rather than diagnostic thresholds. Trend over time on the same lab is more informative than a single value.
Caveats
Same assay-variability caveats as fasting insulin. Not validated for use in established diabetes (insulin secretion has failed by then).
Practices
What's been shown to influence this marker
HOMA-IR improvement parallels fasting-insulin reductions on the Mediterranean pattern; PREDIMED-Plus showed meaningful changes over 12 months.
Aerobic training improves HOMA-IR within 8–12 weeks in adults with insulin resistance, independent of weight.
HabitMediterranean dietary pattern
Olive oil, fish, nuts, legumes, plants. The most-studied diet for cardiovascular and cognitive longevity.
Why
The Mediterranean pattern, heavy on plants, olive oil, fish, nuts, legumes; moderate fish and dairy; light on red meat, has the strongest evidence base of any specific diet for long-term cardiovascular and cognitive outcomes. PREDIMED, the largest trial, showed ~30% reduction in major cardiovascular events vs. low-fat control.
Slot in your day
How to do it
How
Olive oil as the primary fat. Plants at every meal. Fish 2–3× per week. Nuts daily (small handful). Red meat once a week or less. Wine optional, with food.
Sticking with it
Stock the kitchen for one week's pattern. Decisions live in the shopping list, not at mealtime.
Markers this may influence
Evidence
PREDIMED (Estruch 2018 NEJM, n=7,447, 4.8-y follow-up): a Mediterranean diet plus extra-virgin olive oil or mixed nuts vs. a low-fat control diet, ~30% reduction in major cardiovascular events (MI, stroke, CVD death). Sofi 2014 updated meta-analysis (n>4M) confirms a dose-response association with all-cause and cardiovascular mortality.
CautionHabit16:8 intermittent fasting
16-hour overnight fast, 8-hour eating window. Not new, monastic traditions have done it for centuries.
Why
A daily eating window of about 8 hours (e.g., noon to 8pm) with the rest of the day fasted. Often improves insulin sensitivity and reduces visceral fat in trials, though the mechanism is largely the spontaneous calorie reduction it produces rather than fasting per se. Easy entry-level intervention.
Slot in your day
How to do it
How
Skip breakfast or skip dinner. Black coffee, tea, water during the fast. No special protocol needed; consistency over weeks matters more than perfection on any one day.
Ideal for
People with metabolic syndrome, insulin resistance, or who tend to graze.
Sticking with it
Decide your eating window for the week, not the day. Drift is the failure mode.
Markers this may influence
Evidence
Patikorn 2021 JAMA Network Open umbrella review (11 meta-analyses): intermittent-fasting protocols (including 16:8 time-restricted eating) produced modest reductions in body weight, fasting glucose, and LDL-C vs control diets, the effect is largely mediated by the spontaneous calorie reduction the eating window produces. No clear superiority over conventional caloric restriction.
HabitZone 2 cardio
Conversational-pace cardio, 150+ minutes per week. Mitochondrial backbone of healthspan.
Why
Zone 2 is the intensity at which you can still hold a conversation but a song would be a stretch, roughly 60–70% of max heart rate. Sustained Zone 2 work increases mitochondrial density, improves fat oxidation, and is the single most consistently associated exercise input with all-cause mortality reduction in cohort studies.
Slot in your day
How to do it
How
Brisk walk, easy bike, slow jog. 30 minutes × 5 days, or 45–60 min × 3 days. The 'talk test' is the simplest gauge.
Ideal for
Anyone over 30; especially valuable as the foundation before adding higher-intensity work.
Sticking with it
Schedule it like a meeting. The session you 'fit in if there's time' is the session that doesn't happen.
Markers this may influence
Evidence
Lee 2012 Lancet Physical Activity Series (population-attributable risk analysis across >50 cohorts): physical inactivity caused ~9% of premature mortality worldwide, comparable to smoking and obesity. Kelly 2014 meta-analysis of walking and cycling (n=280,000 + n=187,000): each ~11 MET-h/week of either activity was associated with ~10–11% lower all-cause mortality.
HabitResistance training
2 sessions/week. Preserves muscle mass: the marker that tracks functional independence in your eighties.
Why
Sarcopenia (age-related muscle loss) starts in the third decade and accelerates from 50. Resistance training is the only intervention shown to reverse it. Two sessions per week of full-body work is enough to maintain mass; three is enough to build it. Critical for fall prevention, bone density, and insulin sensitivity in older age.
Slot in your day
How to do it
How
Six compound movements (squat, hinge, push, pull, carry, rotate), 2–3 sets each, 2× per week. Bodyweight is fine to start; progress to weighted as form solidifies.
Ideal for
Everyone, especially those over 40; the cost of starting late is much higher than starting early.
Sticking with it
Two fixed weekday slots beat 'three sessions whenever'. The schedule is the programme.
Markers this may influence
Evidence
Westcott 2012 Curr Sports Med Rep review: 2–3 weekly sessions of resistance training in older adults produced ~1.4 kg of muscle gain and ~1.8 kg fat loss over 10 weeks, with parallel gains in resting metabolic rate and glucose handling. The only intervention shown to reverse age-related sarcopenia, which begins in the third decade and accelerates after 50.
See also
Related markers
Take to your physician
Worth discussing
- If elevated, whether lifestyle intervention (Mediterranean pattern + resistance training + cardio) is appropriate.
- Whether the result correlates with your clinical picture (waist circumference, NAFLD, lipids).
- When to recheck after intervention, typically 3–6 months.
Sources
Cited literature
- [1]Matthews et al., Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin(1985)
- [2]Salas-Salvadó et al., PREDIMED-Plus: Effect of a lifestyle intervention on cardiometabolic risk factors(2019)
- [3]Boulé et al., Effects of exercise on glycemic control: a meta-analysis (JAMA)(2001)
Last reviewed May 2026
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