This case study reveals the benefits of careful consideration of the equity dimensions of the topic you wish to study including approaches to measurement and illustrates the implications of context mapping for question formulation, study design, analysis and policy/practice recommendations. It speaks to all four sections of the HIAT which is why it has been included as an illustrative case study in all HIAT sections.

In reviewing the existing literature on obesity and its measurement, Mark Green and colleagues (2016) found that there had been “relatively little consideration of the population-level heterogeneity of those classified as obese”. They developed an important critique of the Body Mass Index (BMI) as a classificatory tool to measure and classify group “individuals in terms of their height and weight as obese”. On the basis of this critique, they hypothesised that such classification “fails to account for the variation within this group across other factors such as health, demographic and behavioural characteristics”.

Redefining traditional categorisations of obesity to include population heterogeneity required redefining their research question to make it more equity sensitive and undertaking analyses to investigate the existence of subgroups of obese individuals. Their research findings also opened up debates about the need to develop differing strategies/interventions in helping the subgroups they identified to lose weight.