Qual Quant (2015) 49:2577–2593
Education and BMI: a genetic informed analysis
Sara Della Bella · Mario Lucchini
Published online: 16 November 2014
© Springer Science+Business Media Dordrecht 2014
Abstract Nowadays obesity is one of the key health risk factor. The negative association
between obesity and education is widely known and, although the mechanisms underlying
this relationship are far less clear, it is often interpreted as a causal one. In this work we
aim to investigate the relationship between education and Body Mass Index (BMI) applying
behavioral genetics models to data coming from the Italian Twin Registry (more precisely, a
subsample of 619 pairs of Mz and 335 pairs of same sex Dz twins). Variance decomposition
models reveal that for both education and BMI heritability should not be overlooked. Above
all, Cholesky decomposition model shows that around 30 % of the covariance between BMI
and Title Page with all Author Contact Details education is due to common genetic factors.
This result may suggest to rethink the relationship between education and BMI.
Keywords Obesity · Education · Cholesky decomposition · Twins data
1 Theoretical framework
Obesity is one of the most grievous examples of contemporary social inequalities in health.
Whilst in the past obesity was a minority phenomenon, largely conﬁned to afﬂuent coun-
tries and privileged socio-economical groups, in the past twenty years the prevalence of
obesity has increased to such an extent that the WHO (2000) speaks of a “global obesity
epidemic”. Moreover, today the prevalence of obesity is higher in the socially–conomically
disadvantaged sections of society.
This is a cause for serious concern because various epidemiological and clinical stud-
ies have shown that obesity is a major risk factor for a series of chronic and fatal diseases
(such as cardiovascular diseases, tumours of various kinds, type-two diabetes, muscular-
S. Della Bella (
L.U.de.S, Lugano, Switzerland
University of Milano Bicocca, Milan, Italy