Obesity

Relevance

Obesity is associated with a long list of adult health conditions, including heart disease, high blood pressure and strokes, type 2 diabetes, various types of cancer, and psychological and social problems. Obese children are likely to be obese into adulthood.³⁶

Current level and trends

In 2006/2007, the age-standardised obesity prevalence rate for the population aged 15 years and over was 25 per cent. This was similar to the 2002/2003 rate of 24 per cent but a significant increase from the 1997 rate of 19 per cent.³⁷

In 2006/2007, 8 per cent of children aged 5–14 years were obese, a prevalence rate similar to that of 2002 (9 per cent).³⁸

The major drivers of the increase in obesity rates have been changing dietary and physical activity patterns, reflecting an environment that promotes the over-consumption of energy-dense foods and drinks and limits the opportunities for physical activity.³⁹

Figure H5.1 Age-standardised prevalence of obesity, total population aged 15 years and over, by sex, 1997, 2002/2003 and 2006/2007

Source: Ministry of Health

Age and sex differences

Age-standardised prevalence rates for 2006/2007 showed no significant sex difference in the proportion of the population aged 15 years and over who were obese (males, 25 per cent; females, 26 per cent). This was also the case in 2002/2003. In 1997, the age-standardised rate for females was significantly higher than the rate for males.

Among children aged 5–14 years, there was no significant difference by sex or age in the prevalence of obesity, either in 2002 or in 2006/2007.

Among those aged 15 years and over in 2006/2007, the prevalence of obesity was highest in the 55–64 years age group (36 per cent), followed by the 65–74 years age group.

Table H5.1 Prevalence (%) of obesity, by age group and sex, 2006/2007

Source: Ministry of Health

Ethnic differences

There are large differences in the prevalence of obesity by ethnicity. Among the population aged 15 years and over in 2006/2007, Pacific peoples (65 per cent) and Māori (43 per cent) had significantly higher age-standardised obesity rates than the total population in this age group, while Asians (12 per cent) had a significantly lower rate. The obesity rate of European/Other was (23 per cent). For Māori, there was no significant change from 1997 to 2006/2007 in the prevalence of obesity, adjusted for age, either for men or for women. Between 2002/2003 and 2006/2007, only Asians had a statistically significant increase in obesity.

Among children aged 5–14 years in 2006/2007, the pattern of ethnic differences in the prevalence of obesity was similar to that of the population aged 15 years and over. Pacific children had the highest rate (26 per cent), followed by Māori children (13 per cent), Asian children (6 per cent) and children of European/Other ethnic groups (5 per cent).

Figure H5.2 Age-standardised prevalence of obesity, population aged 15 years and over, by ethnic group, 1997, 2002/2003 and 2006/2007

Source: Ministry of Health
Note: People who reported more than one ethnic group are counted once in each group reported

Socio-economic differences

The prevalence of obesity is higher in relatively deprived neighbourhoods. In 2006/2007, 38 per cent of the population aged 15 years and over living in NZDep2006 quintile 5 (the most disadvantaged fifth of neighbourhoods) were obese, compared with 26 per cent of those living in quintile 4, 23 per cent of those living in quintile 3 and 21 per cent of those living in quintiles 1 and 2.

International comparison

New Zealand has a relatively high prevalence of obesity compared with other OECD countries. In 2006/2007, New Zealand’s unadjusted rate was 26.5 per cent, compared to an OECD median of 14.9 per cent. New Zealand had the third highest rate out of 30 OECD countries reporting obesity prevalence from 1999–2007. However, most countries use the self-reporting method to measure obesity whereas New Zealand and seven other countries use actual measurements recorded by an interviewer. Out of the eight countries that use actual measurements, New Zealand had the second highest obesity rate after the United States (34.3 per cent in 2006), and a similar rate to the United Kingdom (24.0 per cent in 2007) and Australia (21.7 per cent in 1999). Out of all OECD countries, Japan (3.4 per cent in 2006) and Korea (3.5 per cent in 2005) had the lowest prevalence of obesity.⁴⁰

» View technical details about the obesity indicator