The positive association between number of children and obesity in Iranian women and men: results from the National Health Survey.
BACKGROUND
To date, few studies have assessed the association between the number of children and obesity in couples. We aimed to investigate this association in men and women aged 20-75 years.


METHODS
Data from the National Health Survey were considered in this investigation. It included 2728 women and men (1364 couples) aged 20-75 years. Height and weight were actually measured rather than self-reported. A generalized estimating equation model was used to estimate the odds of obesity (body mass index (BMI > or = 30)) as a function of the number of children adjusted for age, sex, education, economic index, workforce, smoking and place of residence.


RESULTS
We infer that each additional child has at least 5% and at most 34% increase in the odds of obesity in men and at least 4% and at most 29% increase in the odds of obesity in women. Our test of interaction by sex showed that the association between the number of children and obesity was not different among men and women. Among women, factors that increased obesity included age, low education, having more children, being inactive workforce and being nonsmoker. Among men, these factors included high economic index, low education, having more children, and being nonsmoker.


CONCLUSIONS
Our results show an association between the number of children and obesity among men. We would recommend interventions to reduce the number of children to prevent obesity in men.
Department of Biostatistics, School of Public Health and Institute of Public Health Research, Tehran University/Medical Sciences, Iran. eshraghian@yahoo.com
Enayatollah
E
Bakhshi
Mohammad Reza
MR
Eshraghian
Kazem
K
Mohammad
Abbas Rahimi
AR
Foroushani
Hojat
H
Zeraati
Akbar
A
Fotouhi
Fraidon
F
Siassi
Behjat
B
Seifi
D000328:Adult; D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D005191:Family Characteristics; D005260:Female; D006306:Health Surveys; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000145:classification / Q000453:epidemiology*; D012111:Residence Characteristics / Q000706:statistics & numerical data; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology; D012959:Socioeconomic Factors