TOBIN HealthOSChronic-disease intelligence

TOBIN Intelligence Library · evidence review

Obesity & Metabolic Dysfunction

Obesity is modeled as a disorder of energy signaling rather than a BMI value: endocrine-active exposures, mitochondrial and redox function, insulin, leptin, thyroid and sex-hormone signaling, adipose inflammation, microbiome relationships and nutrient adequacy are each evaluated separately.

Obesity & Metabolic Dysfunction on TOBINintel.org →

What is well established

2 links
  • Visceral adipose inflammation → Insulin resistanceA

    Macrophage infiltration and cytokine release impair insulin receptor substrate signaling; consistently reproduced across human and animal evidence.

    Established causal · Multiple high-quality guidelines or meta-analyses

  • Ultra-processed dietary pattern → Excess energy intake and weight gainA

    Controlled feeding trials show higher ad-libitum energy intake and weight gain on ultra-processed diets at matched macronutrients.

    Randomized evidence · Multiple high-quality guidelines or meta-analyses

What is suspected, not proven

2 links
  • Endocrine-active chemical exposure → Receptor and signaling interactionD

    In-vitro and animal work shows nuclear-receptor binding and altered transcription of adipogenic genes. Human exposure data come from population biomonitoring; detection alone does not establish an effect.

    Open question: the mechanism is shown in cells or animals; human outcome trials are still needed.

  • Altered insulin and leptin signaling → Adipocyte dysfunctionB

    Cohort data link hyperinsulinemia and leptin resistance to adipocyte hypertrophy and impaired lipolysis; interventional data are narrower.

    Open question: the association may reflect confounding or reverse causation; intervention trials would settle it.

iDetection of an exposure does not establish that it caused a disease. This platform separates exposure, association, plausible mechanism, clinical evidence and demonstrated causation.

Domain emphasis

B Hormonal Balance · 1O Oxidative Stress · 0.9I Inflammation & Infection · 0.8N Nutrition · 0.8T Toxins · 0.7

Bacteriome shifts and SCFA production are evaluated as a dysbiosis hypothesis, not an infection. Antimicrobials are not indicated on the basis of a microbiome pattern alone.

Related Quadpandemics

  • I · Estrogen & Endocrine Disruption

    Endocrine-active chemicals are widely measurable in the population; their health effects must be evaluated exposure by exposure.

  • II · Obesity & Metabolic Dysfunction

    Obesity is a signaling and exposure problem, not a number on a scale.

  • IV · Anxiety, Depression & Neurobehavioral Health

    Mood symptoms are assessed responsibly — never automatically attributed to toxins or hormones.

Labs that inform this review

  • HbA1c (4.0–5.6 %) — Average glycemia over roughly three months; central to Pandemic II. Discuss any value of 6.5% or higher with a clinician promptly.
  • Fasting insulin (2.0–8.0 µIU/mL) — Insulin signaling load; pairs with glucose for HOMA-IR. Marked elevation with symptoms warrants clinician review.
  • ApoB (< 90 (lower if high risk) mg/dL) — Atherogenic particle count; better risk discrimination than LDL-C alone. Persistently high values deserve a cardiovascular risk discussion.
  • TSH (0.4–4.0 mIU/L) — First-line thyroid signaling test. Any abnormal result should be confirmed and reviewed clinically.
  • Estradiol (Cycle- and sex-dependent pg/mL) — Central to Pandemic I assessment, interpreted with cycle timing. Interpretation requires a clinician who knows your cycle and medication context.
  • Free T4 (0.8–1.8 ng/dL) — Circulating thyroid hormone; confirms whether an abnormal TSH reflects true thyroid under- or over-function. Low free T4 with symptoms, or any high value with palpitations, needs clinician review promptly.
  • Free T3 (2.3–4.2 pg/mL) — Active thyroid hormone, formed mostly by conversion of T4 in tissues. High free T3 with low TSH suggests hyperthyroidism — see a clinician.
  • Reverse T3 (9–24 ng/dL) — Inactive T4 metabolite that rises in stress, illness and calorie restriction. Do not change thyroid medication on rT3 alone; discuss with a clinician.
  • Total cholesterol (< 200 mg/dL) — Sum of cholesterol in all lipoproteins. Values ≥300 mg/dL suggest a genetic lipid disorder — see a clinician.
  • LDL cholesterol (< 100 mg/dL) — Cholesterol carried in LDL; main treatment target in guidelines. LDL-C ≥190 mg/dL warrants clinician evaluation for familial hypercholesterolemia.
  • Non-HDL cholesterol (< 130 mg/dL) — Total minus HDL cholesterol — captures all atherogenic particles' cholesterol. Discuss persistently high values with a clinician.
  • LDL particle number (LDL-P) (< 1000 nmol/L) — NMR count of LDL particles (Labcorp NMR LipoProfile); particle number drives arterial entry. High LDL-P with other risk factors deserves a cardiovascular risk discussion.
  • Small LDL-P (≤ 527 nmol/L) — Number of small, dense LDL particles — an insulin-resistance lipid pattern. Review with a clinician as part of overall risk.
  • LDL particle size (> 20.5 nm) — Average LDL size; ≤20.5 nm is called pattern B (small, dense). Interpret with particle number rather than alone.
  • HDL particle number (HDL-P) (≥ 30.5 µmol/L) — Number of HDL particles; may reflect protective capacity better than HDL-C. Interpret in a clinician-led risk assessment.
  • Lp(a) (< 75 (risk-enhancing ≥ 125) nmol/L) — Genetically determined lipoprotein; independent cause of atherosclerosis and aortic stenosis. Lp(a) ≥125 nmol/L warrants clinician review of overall cardiovascular risk.
  • sdLDL-C (small dense LDL) (< 30 (lab-specific) mg/dL) — Cholesterol in small dense LDL (Quest Cardio IQ, Boston Heart). Review with a clinician as part of overall risk.
  • Oxidized LDL (< 60 (lab-specific) U/L) — LDL damaged by oxidation; marker of oxidative stress on lipids. Interpret with a clinician; do not use alone for decisions.

Score cutoffs used

  • HbA1c ADA Standards of Care: 5.7–6.4% prediabetes, ≥6.5% diabetes range
  • Fasting glucose ADA: 100–125 mg/dL impaired fasting glucose, ≥126 diabetes range
  • Fasting insulin Common functional reference; interpret only with a true fasting sample
  • ApoB ACC/AHA & ESC: ApoB ≥130 mg/dL is a risk-enhancing factor
  • Triglycerides NCEP ATP III: 150–199 borderline, 200–499 high, ≥500 very high
  • HDL cholesterol NCEP ATP III: <40 mg/dL low (men), <50 (women)
  • ALT ACG: upper limit of normal ≈ 29–33 U/L (men), 19–25 (women)
  • GGT Typical laboratory upper limit ≈ 50 U/L
  • TSH ATA/Endocrine Society: 0.4–4.5 mIU/L; >10 overt range
  • Homocysteine >15 µmol/L elevated in most laboratory references
  • Free T4 Typical reference 0.8–1.8 ng/dL (assay-specific); interpret with TSH (ATA)
  • Free T3 Typical reference 2.3–4.2 pg/mL; low T3 also occurs in illness and calorie restriction
  • Reverse T3 Typical reference 9–24 ng/dL; guidelines (ATA) do not recommend rT3 for routine diagnosis — grade D
  • Anti-TPO antibodies Common cutoff >34–35 IU/mL (assay-specific); marks Hashimoto's risk (ATA)
  • Thyroglobulin antibodies Common cutoff ≤4 IU/mL (Roche) — assay-specific; positive in ~60–80% of Hashimoto's
  • Total cholesterol NCEP ATP III: <200 desirable, 200–239 borderline, ≥240 high
  • LDL cholesterol ACC/AHA 2018: ≥190 mg/dL severe; 160–189 high; optimal <100
  • Non-HDL cholesterol NLA: non-HDL <130 mg/dL desirable
  • LDL particle number (LDL-P) NMR LipoProfile (Labcorp): <1000 optimal, 1300–1599 borderline-high, ≥1600 high; MESA
  • Small LDL-P NMR LipoProfile: ≤527 nmol/L reference
  • LDL particle size NMR: >20.5 nm pattern A, ≤20.5 pattern B
  • HDL particle number (HDL-P) NMR LipoProfile: ≥30.5 µmol/L reference
  • Lp(a) ACC/AHA & EAS 2022: ≥125 nmol/L (≥50 mg/dL) risk-enhancing; measure once in lifetime
  • sdLDL-C (small dense LDL) Denka assay (Quest Cardio IQ, Boston Heart): <30 mg/dL optimal (lab-specific)
  • Lp-PLA2 activity PLAC Activity test (FDA-cleared): >123 nmol/min/mL higher risk
  • Oxidized LDL Lab-specific (Cleveland HeartLab ~<60 U/L); research-grade, grade C

Key formulas and thresholds

Published clinical cutoffs
  • HOMA-IR = fasting glucose (mg/dL) × fasting insulin (µIU/mL) ÷ 405 — above 2.5 suggests insulin resistance (Matthews 1985).
  • BMI = weight (kg) ÷ height (m)² — 25–29.9 overweight, 30 or more obesity (WHO); lower cutoffs (23/27.5) for many Asian populations.
  • Waist-to-height ratio = waist ÷ height — 0.5 or more signals central adiposity (NICE 2022).
  • TG/HDL ratio = triglycerides ÷ HDL (mg/dL) — above 3 is associated with insulin resistance (observational).
  • HbA1c (%): concern above 5.6, scored 100 at 8 — ADA Standards of Care: 5.7–6.4% prediabetes, ≥6.5% diabetes range
  • Fasting glucose (mg/dL): concern above 99, scored 100 at 180 — ADA: 100–125 mg/dL impaired fasting glucose, ≥126 diabetes range
  • Fasting insulin (µIU/mL): concern above 8, scored 100 at 40 — Common functional reference; interpret only with a true fasting sample
  • ApoB (mg/dL): concern above 90, scored 100 at 160 — ACC/AHA & ESC: ApoB ≥130 mg/dL is a risk-enhancing factor
  • Triglycerides (mg/dL): concern above 149, scored 100 at 500 — NCEP ATP III: 150–199 borderline, 200–499 high, ≥500 very high
  • HDL cholesterol (mg/dL): concern below 50, scored 100 at 20 — NCEP ATP III: <40 mg/dL low (men), <50 (women)
  • ALT (U/L): concern above 33, scored 100 at 200 — ACG: upper limit of normal ≈ 29–33 U/L (men), 19–25 (women)
  • GGT (U/L): concern above 50, scored 100 at 200 — Typical laboratory upper limit ≈ 50 U/L
  • TSH (mIU/L): concern above 4.5, scored 100 at 20; concern below 0.4, scored 100 at 0.01 — ATA/Endocrine Society: 0.4–4.5 mIU/L; >10 overt range
  • Homocysteine (µmol/L): concern above 10, scored 100 at 30 — >15 µmol/L elevated in most laboratory references
  • Free T4 (ng/dL): concern below 0.9, scored 100 at 0.5; concern above 1.8, scored 100 at 3.5 — Typical reference 0.8–1.8 ng/dL (assay-specific); interpret with TSH (ATA)
  • Free T3 (pg/mL): concern below 2.5, scored 100 at 1.8; concern above 4.4, scored 100 at 7 — Typical reference 2.3–4.2 pg/mL; low T3 also occurs in illness and calorie restriction
  • Reverse T3 (ng/dL): concern above 24, scored 100 at 40 — Typical reference 9–24 ng/dL; guidelines (ATA) do not recommend rT3 for routine diagnosis — grade D
  • Anti-TPO antibodies (IU/mL): concern above 34, scored 100 at 500 — Common cutoff >34–35 IU/mL (assay-specific); marks Hashimoto's risk (ATA)
  • Thyroglobulin antibodies (IU/mL): concern above 4, scored 100 at 200 — Common cutoff ≤4 IU/mL (Roche) — assay-specific; positive in ~60–80% of Hashimoto's
  • Total cholesterol (mg/dL): concern above 199, scored 100 at 300 — NCEP ATP III: <200 desirable, 200–239 borderline, ≥240 high
  • LDL cholesterol (mg/dL): concern above 99, scored 100 at 190 — ACC/AHA 2018: ≥190 mg/dL severe; 160–189 high; optimal <100
  • Non-HDL cholesterol (mg/dL): concern above 129, scored 100 at 220 — NLA: non-HDL <130 mg/dL desirable
  • LDL particle number (LDL-P) (nmol/L): concern above 1000, scored 100 at 2000 — NMR LipoProfile (Labcorp): <1000 optimal, 1300–1599 borderline-high, ≥1600 high; MESA
  • Small LDL-P (nmol/L): concern above 527, scored 100 at 1000 — NMR LipoProfile: ≤527 nmol/L reference
  • LDL particle size (nm): concern below 20.5, scored 100 at 19.5 — NMR: >20.5 nm pattern A, ≤20.5 pattern B
  • HDL particle number (HDL-P) (µmol/L): concern below 30.5, scored 100 at 20 — NMR LipoProfile: ≥30.5 µmol/L reference
  • Lp(a) (nmol/L): concern above 75, scored 100 at 250 — ACC/AHA & EAS 2022: ≥125 nmol/L (≥50 mg/dL) risk-enhancing; measure once in lifetime
  • sdLDL-C (small dense LDL) (mg/dL): concern above 30, scored 100 at 60 — Denka assay (Quest Cardio IQ, Boston Heart): <30 mg/dL optimal (lab-specific)
  • Lp-PLA2 activity (nmol/min/mL): concern above 123, scored 100 at 225 — PLAC Activity test (FDA-cleared): >123 nmol/min/mL higher risk
  • Oxidized LDL (U/L): concern above 60, scored 100 at 100 — Lab-specific (Cleveland HeartLab ~<60 U/L); research-grade, grade C

iThese thresholds organize where to look; they do not diagnose. Laboratory ranges, age, sex and pregnancy change interpretation.

Published sources

Guidelines and landmark studies
Protocols for Obesity & Metabolic DysfunctionCalculate my TOBIN scoresAll reviews