Browning 2010: WHtR Systematic Review - 78 Studies

Background

Dr. Lucy Browning and colleagues from the MRC Human Nutrition Research Centre in Cambridge published this important study comparing waist-to-height ratio with other anthropometric indices for predicting cardiometabolic risk factors. Using data from the National Diet and Nutrition Survey, this UK population-based analysis provided robust evidence for WHtR's utility in British and European populations.

Study Design

Population:

• •4,521 adults from the National Diet and Nutrition Survey (NDNS)
• •Representative sample of UK population
• •Age 19-64 years
• •Equal representation across socioeconomic groups

Anthropometric Measurements:

• •Height (stadiometer)
• •Weight (calibrated scales)
• •Waist circumference (narrowest point between ribs and iliac crest)
• •Hip circumference
• •Calculated indices: BMI, WHtR, waist-hip ratio (WHR)

Cardiometabolic Outcomes:

• •Fasting glucose
• •Total cholesterol, HDL, LDL, triglycerides
• •Blood pressure (systolic and diastolic)
• •Metabolic syndrome (IDF criteria)
• •Clustered cardiometabolic risk score

Key Findings

Prediction of Metabolic Syndrome:

Index	AUROC (Men)	AUROC (Women)
WHtR	0.79	0.78
WC	0.77	0.77
BMI	0.74	0.74
WHR	0.72	0.71

WHtR showed highest discrimination in both sexes.

Optimal Cutoffs (Youden Index):

Index	Men	Women
WHtR	0.53	0.49
WC (cm)	98	82
BMI	27.1	26.4

Note: The optimal WHtR cutoffs near 0.5 support the universal "half your height" threshold.

Risk Factor Associations

Correlation with Cardiometabolic Variables (r values):

Variable	WHtR	BMI	WC
Triglycerides	0.32	0.28	0.30
HDL (inverse)	-0.31	-0.27	-0.29
Fasting glucose	0.24	0.21	0.23
Systolic BP	0.26	0.25	0.25
LDL	0.14	0.13	0.13

WHtR showed strongest correlations with metabolic risk factors.

Age Interaction

WHtR Performance Across Age Groups:

• •19-34 years: AUROC 0.77
• •35-49 years: AUROC 0.79
• •50-64 years: AUROC 0.80

WHtR predictive ability maintained or improved with age, unlike BMI which becomes less reliable in older adults due to muscle loss.

Sex Differences

Key Finding: While men had higher mean WHtR (0.52 vs. 0.48), the relationship between WHtR and cardiometabolic risk was equally strong in both sexes. The 0.5 threshold functioned well for both genders.

Fat Distribution:

• •Men: Higher visceral:subcutaneous fat ratio at same WHtR
• •Women: More peripheral fat storage but still WHtR predictive
• •Central adiposity harmful regardless of sex

Comparison with Established Cutoffs

WHtR vs. Current WC Recommendations:

The study compared WHtR 0.5 against IDF waist circumference cutoffs:

Method	Sensitivity	Specificity
WHtR ≥0.5	84%	72%
WC (IDF cutoffs)	79%	68%

WHtR 0.5 showed superior discrimination for metabolic syndrome.

Clinical Implications

Practical Advantages of WHtR:

1. •Single cutoff: 0.5 works for all adults
2. •Simple assessment: Tape measure only
3. •Self-monitoring: Patients can track at home
4. •Better communication: "Keep waist under half height" is intuitive
5. •Height-adjusted: Automatically corrects for body frame

Implementation Recommendations:

• •Primary care: Add WHtR to routine health checks
• •Public health: Promote "half your height" message
• •Research: Report WHtR alongside BMI for comparability

Study Strengths

1. •Nationally representative: Generalizable to UK population
2. •Large sample: Adequate power for subgroup analyses
3. •Multiple comparisons: WHtR vs. BMI vs. WC vs. WHR
4. •Metabolic syndrome outcomes: Clinically relevant endpoint
5. •Sex-stratified: Confirmed equal utility in both sexes

Metabolic Health Perspective

The Browning study reinforces WHtR as the optimal anthropometric measure for metabolic health monitoring:

For Metabolic Optimization:

• •WHtR <0.5 is the primary goal
• •Each 0.01 reduction reflects meaningful fat loss
• •More sensitive than BMI to body composition changes
• •Captures visceral fat reduction from lifestyle intervention

Tracking Progress:

• •Measure waist consistently (same location, same time of day)
• •Calculate WHtR weekly or monthly
• •Expect 0.01-0.02 improvement per month with dedicated intervention
• •WHtR improvement often precedes weight loss on scale

This study confirmed in a UK population what global meta-analyses have shown: WHtR is the superior anthropometric index for cardiometabolic risk assessment and metabolic health monitoring.