Is there a better measure than BMI to look at the impact of poverty and education on obesity levels?

Alternative measures to the standard Body Mass Index (BMI) currently used to assess for healthy weight have revealed new links between socio-economic situations and obesity, and could be an important new tool for policy makers looking to tackle the UK’s growing obesity problem.

The new study by Dr. Apostolos Davillas and Professor Michaela Benzeval, published in the journal, Social Science and Medicine, used alternative measures of body fat to standard BMI measures, drawing on data from the huge UK Household Longitudinal Study, Understanding Society, to unpick the link between social inequalities and growing levels of obesity.

The study used a variety of obesity measures including body fat (absolute and percentage) and waist circumference in addition to the conventional body mass index (BMI).

The researchers looked at over 13,000 adult participants in a specific health study within Understanding Society and compared income inequalities with both the conventional BMI and the alternative combined measures of waist circumference, body fat and BMI to see if the differences between them shed light on inequalities in the growing levels of obesity in the UK population.

The body fat measures collected by Understanding Society allowed the researchers to distinguish between the fat- and lean-mass components of BMI.

The alternative measurements found wealthier men were less likely to be obese, contrary to previous research using only BMI, which had failed to find a link to wealth and weight gain.

For women, the conventional BMI and alternative measures combination of waist measure, body fat and BMI – showed inequalities in obesity exist whatever the measure.

Dr Apostolos Davillas said:
“By focussing only on BMI previous researchers may have missed the link between income and obesity for men. Our findings could have important implications for the measurement of socio-economic inequalities and any impact this is having on the UK’s growing obesity epidemic. There are important lessons for policy makers here in the value of using alternatives to BMI to assess the nation’s weight gain issues, and why this is happening and how to tackle it.”

Understanding Society collects complex annual data from individuals in households across the UK, including health details, financial, social and lifestyle information as well as beliefs, attitudes and behaviours. The health is study uses objective measures of adiposity taken during an interview conducted by nurses.

Read the Social Science and Medicine journal article Alternative measures to BMI Exploring income-related inequalities in adiposity in Great Britain


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