Conversion uses USDA-standard weight-per-cup densities: Rolled Oats ~90 g/cup, White Rice (raw) ~185 g/cup, Greek Yogurt ~245 g/cup, Peanut Butter ~258 g/cup, Flour ~120 g/cup, Sugar ~200 g/cup. Cups (volume) = weight (g) ÷ density (g/cup). 1 cup = 16 tablespoons.

• USDA FoodData Central – Weight and Measures
• King Arthur Baking – Ingredient Weight Chart
• FDA – Guidance for Industry: Serving Sizes

A Body Shape Index (ABSI) = WC / (BMI^(2/3) × Height^(1/2)), where WC is waist circumference in meters. Developed by Krakauer & Krakauer (2012). ABSI captures the mortality risk associated with abdominal adiposity independently of BMI and height.

• Krakauer NY & Krakauer JC (2012) – A New Body Shape Index Predicts Mortality Hazard (PLoS ONE, PubMed)
• WHO – Waist circumference and waist-hip ratio: WHO expert consultation
• NIH – Assessing Abdominal Obesity

Calorie deficit through walking: ~0.04 kcal burned per step per kg body weight. Additional steps needed = daily calorie deficit (kcal) ÷ calories per step. A deficit of 500 kcal/day ≈ 0.5 kg/week weight loss. Walking distance = total steps × 0.762 m (average stride length).

• Hall KD et al. (2011) – Quantification of the effect of energy imbalance on bodyweight (Lancet, PubMed)
• Lee I-M et al. (2019) – Steps per day and mortality (JAMA Internal Medicine, PubMed)
• CDC – Physical Activity for Healthy Weight

Exercise time = food calories ÷ calories burned per minute for the selected activity. Calories per minute = (MET × 3.5 × body weight kg) ÷ 200. MET values from the Compendium of Physical Activities: Walking ≈3.5, Jogging ≈7.0, Cycling ≈8.0. Food calories sourced from USDA FoodData Central.

• Ainsworth BE et al. (2011) – Compendium of Physical Activities (PubMed)
• USDA FoodData Central
• ACSM – Caloric Expenditure Calculations

Ergonomic dimensions are calculated from user height using anthropometric ratios: Seat height ≈ lower-leg length (≈25% of height), desk height ≈ elbow height when seated (≈43% of height), monitor top ≈ eye level when seated (seat height + torso to eye ≈ 72% of height). Based on OSHA and BIFMA ergonomic standards.

• OSHA – Computer Workstations eTool
• BIFMA – Ergonomic Guidelines for Visual Display Terminal Furniture
• Cornell University Ergonomics – Ideal Typing Posture

Time to sunburn (minutes) = (Minimum Erythemal Dose for skin type) ÷ (UV Index × 0.025). Fitzpatrick skin types I–VI have baseline MED values from 200–800 J/m². SPF extends time: protected time = unprotected time × SPF factor. Based on WHO UV Index system and Fitzpatrick (1988) skin phototype classification.

• Fitzpatrick TB (1988) – The validity and practicality of sun-reactive skin types (Archives of Dermatology, PubMed)
• WHO – Global Solar UV Index: A Practical Guide
• CDC – Sun Safety: UV Index

FFMI = fat-free mass (kg) ÷ height² (m²). Fat-free mass = weight × (1 − body fat % / 100). Normalized FFMI = FFMI + 6.1 × (1.8 − height in m). Developed by Kouri et al. (1995). An FFMI of 25+ is near the upper natural limit for men; values above 26 may suggest anabolic assistance.

• Kouri EM et al. (1995) – Fat-free mass index in users and nonusers of anabolic-androgenic steroids (Clinical Journal of Sport Medicine, PubMed)
• Schutz Y et al. (2002) – Fat-free mass index and fat mass index percentiles (International Journal of Obesity, PubMed)
• ACSM – Body Composition Assessment

Biological age is estimated using a lifestyle-factor model adjusting chronological age: sleep deviation from optimal (7–9h) adds +0.5 to +2 years; exercise <2.5 h/week adds +1–3 years; BMI outside 18.5–24.9 adds +1–2 years; smoking adds +5–10 years. Modelled on epigenetic clock concepts by Horvath (2013).

• Horvath S (2013) – DNA methylation age of human tissues and cell types (Genome Biology, PubMed)
• Levine ME et al. (2018) – An epigenetic biomarker of aging (Aging, PubMed)
• WHO – Healthy Ageing and Functional Ability

Blood pressure categories follow AHA/ACC 2017 guidelines: Normal (<120/<80), Elevated (120–129/<80), Stage 1 Hypertension (130–139 or 80–89), Stage 2 Hypertension (≥140 or ≥90), Hypertensive Crisis (>180 and/or >120). Mean Arterial Pressure (MAP) = DBP + ⅓(SBP − DBP). Pulse Pressure = SBP − DBP.

• Whelton PK et al. (2017) – ACC/AHA Blood Pressure Guideline (Hypertension, PubMed)
• AHA – Understanding Blood Pressure Readings
• CDC – High Blood Pressure Symptoms and Causes

VO₂ Max is estimated using the Uth et al. (2004) formula: VO₂ Max ≈ 15.3 × (MHR ÷ RHR), where MHR = 208 − (0.7 × age) (Tanaka formula). Fitness categories: Poor (<30), Fair (30–40), Good (40–50), Excellent (50–60), Superior (>60) mL/kg/min for adults.

• Uth N et al. (2004) – Estimation of VO₂max from the ratio between HRmax and HRrest (Eur J Appl Physiol, PubMed)
• ACSM – Cardiorespiratory Fitness Classification
• Cooper Institute – VO₂max Normative Data