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Education and BMI: a genetic informed analysis

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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.

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Notes

  1. Body Mass Index, calculated by dividing the individual’s weight in kilograms by the square of his/her height in metres, is a measure of obesity commendable for its simplicity and generally reliable for adults (\(>\)18 years). On the basis of medical-health criteria, the WHO defines an adult person as (a) underweight if s/he has BMI less than 18.5; (b) normal weight if s/he has a BMI between 18.5 and 24.9; (c) overweight if s/he has a BMI between 25 and 29.9, and (d) obese if s/he has a BMI greater than 30.

  2. Some recent studies with the Instrumental Variable method (IV), which supposedly allows to correctly study causal effects, have strengthened the hypothesis of a causal relationship between education and obesity (Brunello et al. 2009; Grabner 2008).

  3. See the Journal of Twin Research and Human Genetics (2002, vol. 5, issue 5 and 2006, vol. 9, issue 6) for two special issues on twins registries around the world. As far as the Italian Twin Registry, see the article by Stazi and colleagues in Twin Research 2002, vol. 5, issue 5, pp. 382–386.

  4. The database used was obtained after a preliminary purging which eliminated the outlier pairs through examination of the distribution of the distances between the BMIs of the twins in the same pair (see Neale and Cardon 1992); in our case four pairs were removed from a total of 1,245 pairs. Finally, we considered only twins aged over 25 years in order to have twins who had completed full-time education.

  5. Notwithstanding the fact that people tend to underestimate their weight and overestimate their height, generally self-reported measures of weight and height are considered to be quite reliable (Boström and Diderichsen 1997; Roberts 1995). It seems that biases in these self-reported measures are linked to personal characteristics like gender, age and real weight and height rather than to individual SES (Roberts 1995; Rowland 1990; Shields et al. 2008). Hence, this kind of bias would affect prevalence estimate but would not significantly affect the relationship between SES and obesity (Roberts 1995).

  6. The fact that heritability is a population-specific statistic implies that caution is necessary when comparing heritability estimates obtained in distinct populations. It is above all necessary to avoid misleading conclusions concerning the nature of differences among groups: if two groups have very different values on a highly heritable trait, this does not entail that such observed differences are caused by genetic factors (Visscher et al. 2008).

  7. In this study both BMI and education are measured as continuous traits. It is true that BMI is not the same that obesity (a dichotomous trait) but the so called “threshold traits” require different methods of analysis (for instance, the DeFries–Fulker analysis of extreme, cf. Plomin 2001). In the case of BMI is not clear whether a dichotomization would be appropriate: the problem is to understand whether obesity represents, from an etiological point of view, a distinct phenomenon from BMI or it is just the extreme of a continuum (hence implying quantitative but not qualitative differences). Often a threshold is artificially imposed by a the scientific community for convenience, in order to easily identify the ones to be treated. However, many studies actually measure traits like depression on continuous scale because the dichotomization of such traits typically result in a loss of statistical power to detect genetic effects (Anholt and Mackay 2009; Neale et al. 1994). For these reasons we choose to consider BMI but we need to be aware that the heritability of BMI may not coincide with that of obesity.

  8. RMSEA is an absolute measure of fit, that presumes that the best fitting model has a fit of zero. Usually the value needs to be below 0.06 to indicate a good fit (Bollen 1989).

  9. As Plomin (2001) point out, it is desirable to maintain the variance component of unshared environment in each model because the measurement error is included in it.

  10. The AIC (Akaike Information’s Criterion) is a comparative measure of fit. In Amos is calculated as \(\chi ^{2}\)—2q where q stands for the number of parameters of the model. Lower values indicate a better fit.

References

  • Allison, D.B., Neale, M., Kezis, M., Vincent, A., Heshka, S., Heymsfield, S.: Assortative mating for relative weight: genetic implications. Behav. Genet. 26, 103–111 (1996)

    Article  Google Scholar 

  • Anholt, R., Mackay, T.: Principles of Behavioral Genetics. Elsevier, Amsterdam (2009)

    Google Scholar 

  • Beauchamp, J.P., Cesarini, D., Johannesson, M., Lindqvist, E., Apicella, C.: On the sources of the height-intelligence correlation: new insights from a bivariate ACE model with assortative mating. Behav. Genet. 41, 242–252 (2001)

    Article  Google Scholar 

  • Blossfeld, H.P., Timm, A.: Who Marries Whom? Educational Systems as Marriage Markets in Modern Societies. Kluwer Academic Publishers, Dordrecht (2004)

    Google Scholar 

  • Bollen, K.A.: Structural Equations with Latent Variables. Wiley, New York (1989)

    Book  Google Scholar 

  • Boström, G., Diderichsen, F.: Socioeconomic differential in misclassification of height, weight and body mass index based on questionnaire data. Int. J. Epidemiol. 26(4), 860–866 (1997)

    Article  Google Scholar 

  • Bouchard, C., Tremblay, A., Despres, J.P., Nadeau, A., Lupien, P.J., Theriault, G., Dussault, J., Moorjani, S., Pinault, S., Foumier, G.: The response to long-term overfeeding in identical twins. New Engl. J. Med. 322, 1477–1482 (1990)

    Article  Google Scholar 

  • Brunello, G., Fabbri, D., Fort, F.: Years of schooling, human capital and the body mass index of european females, IZA Discussion Papers 4667, Institute for the Study of Labor (IZA) (2009)

  • Burt, A.: Heritability in the era of molecular genetics: a comment. Eur. J. Personal. 25, 268–269 (2011)

    Google Scholar 

  • Crosnoe, R.: Gender. Obes. Educ. Soc. Educ. 80, 241–260 (2007)

    Article  Google Scholar 

  • de Castro, J.M., Lilenfeld, L.: The influence of heredity on dietary restraint, disinhibition, and perceived hunger in humans. Nutrition 21, 446–455 (2005)

    Article  Google Scholar 

  • De Irala-Estévez, J., Groth, M., Johansson, L., Oltersdorf, U., Prättälä, R., Martínez-González, A.: A systematic review of socio-economic differences in food habits in Europe: consumption of fruit and vegetables. Eur. J. Clin. Nutr. 54, 706–714 (2000)

    Article  Google Scholar 

  • Dunn, J., Plomin, R.: Separate Lives: Why Siblings are so Different. Basic Books, New York (1990)

    Google Scholar 

  • Freese, J.: Genetics and the social science explanation of individual outcomes. Am. J. Sociol. 114, S1–S35 (2008)

    Article  Google Scholar 

  • Gortmaker, S., Must, A., Perrin, J.M., Sobol, A.M., Dietz, H.: Social and economic consequences of overweight in adolescence and young adulthood. New Engl. J. Med. 329, 1008–1012 (1993)

    Article  Google Scholar 

  • Guo, G., Tong, Y.: Age at first sexual intercourse, genes, and social context: evidence from twins and the dopamine D4 receptor gene. Demography 43, 747–769 (2006)

    Article  Google Scholar 

  • Grabner, M.J.: The Causal Effect of Education on Obesity: Evidence from Compulsory Schooling Laws. http://ssrn.com/abstract=1505075. Accessed 18 May 2014 (2008)

  • Harris, J.R.: The Nurture Assumption. Why Children Turn Out the Way They Do. Free Press, New York (1998)

    Google Scholar 

  • Haworth, C., Dale, P., Plomin, R.: A twin study into the genetic and environmental influences on academic performance in science in 9 years old boys and girls. Int. J. Sci. Educ. 30, 1003–1025 (2008)

    Article  Google Scholar 

  • Herzlich, C., Adam, P.: Sociologie de la Maladie et de la Medecine. Nathan, Paris (1994)

    Google Scholar 

  • Hu, F.B.: Obesity Epidemiology. Oxford University Press, New York (2008)

    Book  Google Scholar 

  • Jang, K.L., Livesley, J., Vernon, P.A.: Heritability of the big five personality dimensions and their facets: a twin study. J. Personal. 64, 577–591 (1996)

    Article  Google Scholar 

  • Johnson, W., Kyvik, K., Skytthe, A., Deary, I., Sørensen, T.: Education modifies genetic and environmental influences on BMI. PLoS One 6, e16290 (2011)

    Article  Google Scholar 

  • Johnson, W., Penke, L., Spinath, F.: Heritability in the era of molecular genetics: some thoughts for understanding genetic influences on behavioural traits. Eur. J. Personal. 25, 254–266 (2011)

    Article  Google Scholar 

  • Lichtenstein, P., Pedersen, N.L., McClearn, G.E.: The origins of individual differences in occupational status and educational level. Acta Sociol. 35, 13–31 (1992)

    Article  Google Scholar 

  • Loehlin, J.C.: The Cholesky approach: a cautionary note. Behav. Genet. 26, 65–69 (1996)

    Article  Google Scholar 

  • Lucchini, M., Della Bella, S., Pisati, M.: The weight of the genetic and environmental dimensions in the inter-generational transmission of educational success. Eur. J. Sociol. (2011). doi:10.1093/esr/jcr067

  • Lynch, J., Kaplan, G.A., Salonen, T.: Why do poor people behave poorly? Variation in adult health behaviours and psychosocial characteristics by stages of the socio-economic lifecourse. Social. Sci. Med. 44, 809–819 (1997)

    Article  Google Scholar 

  • Lyon, H.N., Hirschhorn, J.N.: Genetics of common forms of obesity: a brief overview. Am. J. Clin. Nutr. 82, 215S–217S (2005)

    Google Scholar 

  • Maes, H.H., Neale, M.C., Eaves, L.J.: Genetic and environmental factors in relative body weight and human adiposity. Behav. Genet. 27(4), 325–351 (1997)

    Article  Google Scholar 

  • Martínez-González, M.A., Martínez, J.A., Hu, F.B., Gibney, M.J., Kearney, J., et al.: Physical inactivity, sedentary lifestyle and obesity in the European Union. Int. J. Obes. Rel. Met. Dis. 23, 1192–1201 (1999)

    Article  Google Scholar 

  • McCaffery, J.M., Papandonatos, G.D., Bond, D.S., Lyons, M.J., Wing, R.R.: Gene x environment interaction of vigorous exercise and body mass index among male Vietnam-era twins. Int. Am. J. Clin. Nutr. 89, 1011–1108 (2009)

    Article  Google Scholar 

  • McLaren, L.: Socioeconomic status and obesity. Epidemiol. Rev. 29, 29–48 (2007)

    Article  Google Scholar 

  • Medland, S., Hatemi, P.: Political science, biometric theory and twin studies: a methodological introduction. Polit. Anal. 17, 191–214 (2009)

    Article  Google Scholar 

  • Mutch, D., Clement, K.: Unraveling the genetics of human obesity. PLoS Genet. 2, 1956–1963 (2006)

    Article  Google Scholar 

  • Neale, M., Maes, H.: Methodologies for Genetic Studies of Twins and Families. Kluwer Academic Publisher, Dordrecht (2005)

    Google Scholar 

  • Neale, M.C., Cardon, L.: Methodology for Genetic Studies of Twins and Families. Kluwer Academic Publisher, Dordrecht (1992)

    Book  Google Scholar 

  • Neale, M.C., Eaves, L.J., Kendler, K.S.: The power of the classical twin study to resolve variation in threshold traits. Behav. Genet. 24, 239–258 (1994)

    Article  Google Scholar 

  • Nielsen, F.: The nature of social reproduction: two paradigms of social mobility. In: Mario, L., Maurizio, P. (eds.) Symposium/Social Sciences and Natural Sciences—What Connection? Sociologica 3:1–35 (2008). http://www.sociologica.mulino.it/

  • Pampel, F.C., Krueger, P.M., Denney, J.T.: Socioeconomic disparities in health behaviors. Annu. Rev. Sociol. 36, 349–370 (2010)

    Article  Google Scholar 

  • Plomin, R., Petrill, S.A.: Genetics and intelligence: what’s new? Intelligence 24, 53–77 (1997)

    Article  Google Scholar 

  • Plomin, R., DeFries, J.C., Loehlin, J.C.: Genotype–environment interaction and correlation in the analysis of human behavior. Psychol. Bull. 85, 309–322 (1977)

    Article  Google Scholar 

  • Plomin, R., DeFries, J.C., McClearn, G.E., McGuffin, P.: Behavioral Genetics, 3rd edn. Freeman, New York (2001)

    Google Scholar 

  • Price, R.A.: Genetics and common obesities: background, current status, strategies and future prospects. In: Thomas, A.W., Albert, S. (eds.) Handbook of Obesity Treatment, pp. 73–94. Guilford Press, New York (2004)

    Google Scholar 

  • Puhl, R.M., Brownell, D.: Bias, discrimination, and obesity. Obes. Res. 9, 788–805 (2001)

    Article  Google Scholar 

  • Purcell, S.: Variance component models for geneenvironment interaction in twin analysis. Twin Res. 5, 554–571 (2002)

    Article  Google Scholar 

  • Rankinen, T., Zuberi, A., Chagnon, Y., Weisnagel, J., Argyropoulos, G., Walts, B., Pérusse, L., Bouchard, C.: The human obesity gene map: the 2005 update. Obesity 14, 529–644 (2006)

    Article  Google Scholar 

  • Reed, D.R., Bachmanov, A.A., Beauchamp, G.K., Tordoff, M.G., Price, A.: Heritable variation in food preferences and their contribution to obesity. Behav. Genet. 27, 373–387 (1997)

    Article  Google Scholar 

  • Roberts, R.J.: Can self-reported data accurately describe the prevalence of overweight? Public Health 109, 275–284 (1995)

    Article  Google Scholar 

  • Rowland, L.: Self-reported weight and height. Am. J. Clin. Nutr. 52, 1125–1133 (1990)

    Google Scholar 

  • Rutter, M.: Genes and Behaviour. Nature-Nurture Interplay Explained. Blackwell, Oxford (2006)

    Google Scholar 

  • Shields, M., Connor Gorber, S., Tremblay, M.S.: Estimates of obesity based on self-report versus direct measures. Health Rep. Stat. Can. 19, 2 (2008)

    Google Scholar 

  • Silventoinen, K., Sarlio-Lahteenkorva, S., Koshenvuo, M., Lahelma, E., Kaprio, J.: Effect of environmental and genetic factors on education-associated disparities in weight and weight gain: a study of Finnish adult twin. Am. J. Clin. Nutr. 80, 815–822 (2004)

    Google Scholar 

  • Sobal, J., Stunkard, A.J.: Socioeconomic status and obesity: a review of the literature. Psychol. Bull. 105, 260–275 (1989)

    Article  Google Scholar 

  • Teasdale, T.W., Sørensen, T., Stunkard, J.: Intelligence and educational level in relation to body mass index of adult males. Hum. Biol. 64, 99–106 (1992)

    Google Scholar 

  • Varo, J.J., Martínez-González, M.A., de Irala-Estévez, J., Kearney, J., Gibney, M., Martínez, J.A.: Distribution and determinants of sedentary lifestyles in the European Union. Int. J. Epidemiol. 32, 138–146 (2003)

    Article  Google Scholar 

  • Vermeiren, A., Bosma, H., Gielen, M., Lindsey, P., Derom, C., Vlietinck, R., Loos, R., Zeegers, M.: Do genetic factors contribute to the relation between education and metabolic risk factors in young adults? A twin study. Eur. J. Public Health 23, 986–991 (2012)

    Article  Google Scholar 

  • Visscher, P.M., Hill, W.G., Wray, N.R.: Heritability in the genomics era. Concepts and misconceptions. Nat. Rev. 9, 255–264 (2008)

    Article  Google Scholar 

  • Wardle, J., Waller, J., Jarvis, M.: Sex differences in the association of socioeconomic status with obesity. Am. J. Public Health 92, 1299–1304 (2002)

    Article  Google Scholar 

  • WHO.: Obesity: Preventing and Managing the Global Epidemic: Report of a WHO Consultation. WHO Technical Report Series no. 894, WHO, Geneve (2000)

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Della Bella, S., Lucchini, M. Education and BMI: a genetic informed analysis. Qual Quant 49, 2577–2593 (2015). https://doi.org/10.1007/s11135-014-0129-1

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