Prevalence of obesity and overweight among adults in Iran

Authors


SMT Ayatollahi, Professor of Biostatistics, the Medical School, Shiraz University of Medical Science, PO Box 71345-1874, Shiraz, I.R. Iran. E-mail: ayatolahim@sums.ac.ir

Summary

The prevalence of overweight and obesity in most developed and developing countries have been increasing markedly over the past two decades. This increase includes all ages, genders, racial and ethnic groups, income, and educational levels. This study examined the prevalence of overweight and obesity among adults aged 25–55 years in Shiraz (Southern Iran). The data are based on a random multistage sample survey of 2282 married adults (1141 pairs) living is Shiraz, whose heights and weights were measured in the 2002–2003 academic year. The prevalence of overweight or obesity (body mass index ≥ 25) was 49.7% in men and 63.9% in women. The prevalence of obesity (body mass index ≥ 30) was 10.5% and 22.5% in men and women, respectively, which shows an increased secular change of 5.8% in men and 17.4% in women during a 14-year period. Overweight and obesity are common in Iran. Obesity and overweight were significantly more common among women than among men (P-valve = 0.000). There is a need to establish programmes for prevention and treatment of obesity especially Iranian's women.

Introduction

Obesity has become one of the most important health problems throughout the world (1). Adults' obesity is a serious health concern and is associated with many chronic diseases, including cardiovascular disease, diabetes, arthritis, gall bladder diseases, certain cancers and respiratory diseases (2). Increasing obesity is a function of increased caloric intake and decreased energy expenditure (2). Body mass index (BMI: weight (kg)/height (m)2) is currently the most widely used standard to define stages of elevated body weight (2). Several methods been developed to measure body fat, including densitometry, ultra sonography, computed tomography, magnetic content, levels of creatinine and total body matter content. These methods are not widely available and are usually expensive and time-consuming and require qualified personnel (3). BMI is the preferred method of expressing body fat percentiles of groups in childhood and adolescence.

The present study aimed at determining the prevalence of overweight and obesity among the adults of Shiraz (Iran), and examines gender as well as age differences in obesity prevalence.

Materials and methods

Subjects

The data related to a random sample of 2282 married adults (1141 pairs) aged 25–55 years. Mean ± standard deviation ages of husbands and wives were 39.9 ± 5.7 and 34.1 ± 5.7, respectively. They were selected by a multistage sampling scheme and forming a 2% sample of the primary schools parents from the four educational districts of Shiraz (Southern Iran), one of the five principal cities of Iran, in academic year 2002–2003.

Body weight (in km) and body height were measured to the nearest 0.1 kg and 0.1 cm, respectively, by the research team, using a SECA-marked stadiometer and the techniques presented by Cameron (4). Weights were measured with clothing, as a result of sociocultural circumstances. Depending on its type, an average weight of clothing was subtracted from the measured weight giving the real naked weight of the subject.

Methods

The BMI as weight/(height)2 (kg/m2) was calculated for each individual, and the results were categorized for each sex by age groups of 5 years. Obesity is defined as a BMI ≥ 30 and overweight defined as 25 ≤ BMI < 30. Statistical analyses were performed using spss software (spss for windows version 11.5) and a trend test was carried out using epiinfo software.

Results

The prevalence of obesity and overweight in relation to the age groups of men and women was shown in Table 1. The prevalence of overweight or obesity (BMI ≥ 25) and obesity (BMI ≥ 30) to be found 49.7% and 10.5%, respectively, in men, and 63.9% and 22.5% in women. Obesity and overweight or obesity were significantly more among women than among men (P-value = 0.000) although there was an increasing trend in the women's obesity by increasing the age (Trend P-value = 0.012).

Table 1.  The prevalence of overweight and obesity in adults of Shiraz by sex and age, 2003
Age (years)MenWomenP-value for sex
NOverweight n (%)Obese n (%)NOverweight n (%)Obese n (%)Difference
OverweightObese
25–29112 (18.2)1 (9.1)258102 (39.4)48 (18.5)0.2140.692
30–3419467 (34.5)22 (11.3)393171 (43.5)85 (21.6)0.0400.002
35–39379144 (38)42 (11.1)272112 (40.7)67 (24.4)0.6260.000
40–44299137 (45.8)27 (9)15869 (43.4)39 (24.5)0.5550.000
45–4917970 (39.1)19 (10.6)4414 (31.8)13 (29.5)0.3920.003
50–557927 (34.2)9 (11.4)114 (36.4)5 (45.5)1.0000.012
All1141447 (39.2)120 (10.5)1141472 (41.4)257 (22.5)0.3930.000
95% confidence intervals(36.23–42.1)(8.8–12.5)(38.2–43.9)(20.1–25)

Discussion

We found that obesity and overweight are common in Iran. A comparison of our data with a former study in Shiraz carried out by the principal author in 1988–1989 shows an increasing prevalence of obesity from 4.7% to 10.5% among men and from 5.1% to 22.5% among women (5), which shows an increased secular change of 5.8% in men and 17.4% in women during a 14-year period between the two studies. Another study carried out 8 years later shows obesity prevalence of 2.5% and 8% among males and females, respectively, which indicate an increasing trend in the pattern of adults' obesity in Iran (6). This may be due to the post-war (1988 onwards) reconstruction and development period. Similar results obtained in prevalence studies in Isfahan (central Iran) (7) and Khorramabad (western Iran) (8), but obesity prevalence was almost doubled in Tehran (the Irans capital), which might be attributed to minimal physical activity lifestyle of the capital residents.

Obesity and overweight (BMI ≥ 25) in women were significantly more common than men (P-value = 0.000) and obesity trends increased with age in women and higher values found among 50–55 age group.

This result may be due to Iranian women have less physical activities than men because of limited outdoor climatic and/or social conditions, and or limited number of fitting saloons and physical exercise clubs, also childbirth can be another reason.

Prevalence of obesity and overweight in Iran is higher than the value reported in Pakistan (9), Singapore (10), China (11), Western India (Mumbai) (12), Sweden (MalmÖ) (13) but lower than the prevalence in the USA (14), Europe (15), Turkey (16), Bahrain (17) and Saudi Arabia (18).

Changing dietary habits, using of junk food and limited physical activity pattern due to rapid urbanization, modernization can be reasons for the increase in BMI of Iranian adults. There is a need to establish programmes for promoting awareness among the population of the health hazards and means of control for obesity.

Conflict of Interest Statement

No conflict of interest was declared.

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