Obesity is an excessively high amount of body fat in relation to lean body mass, defined as having a Body Mass Index (BMI, calculated as kg/m²) of 30+, or equivalent for those aged under 18 years . Obesity is associated with an increased risk of a number of health conditions, including type 2 diabetes, ischaemic heart disease, high blood pressure, some cancers, some forms of arthritis, and stroke . Rates of obesity have increased in almost all countries in the past three to four decades and New Zealand now has one of the highest rates of obesity in the world [24,25]. Most of this increase has been attributed to increased access to foods that are more processed, affordable, and effectively marketed . Energy-dense and nutrient-poor foods have become the most affordable way to meet daily calorie needs compared to nutrient-rich and high-quality foods, resulting in low income groups generally having a poorer diet than high income groups . Policies and programmes that make it easier to eat healthily and exercise regularly are required to reduce obesity at the population level.
This indicator presents the proportion of those 15 years and over who are obese (Body Mass Index, calculated as kg/m², of 30+, or equivalent for those aged <18 years), using New Zealand Health Survey data.
The figure shows that approximately a quarter of adult respondents (23.3%) were obese across the Canterbury DHB region in 2019/20. This proportion is statistically significantly lower than the proportion for New Zealand overall (30%). The proportion of respondents aged 15 years and over who are obese in New Zealand increased statistically significantly between 2011/12 and 2017/18 but has declined marginally since. The proportion of Canterbury respondents aged 15 years and over who are obese has also declined since 2017/18, however, the differences between timepoints are not statistically significant.
The figure shows that the proportion of Canterbury DHB region respondents, aged 15 years and over, who were obese was highest for Pacific people over the time series shown, compared with Māori, Asian, and European/Other respondents (in 2017–2020, Pacific, 50.5%; Māori, 35.4%; European/Other 25.5%, and Asian, 7.6%). The proportion of adult Māori and Pacific respondents who are obese has declined over the time series shown (notably for Pacific people), although the differences are not statistically significant.
The figure shows that the proportion of respondents aged 15 years and over who are obese in the Canterbury DHB region is higher for the older age groups, in particular for those aged 25 to 44 years (26.4%), 45 to 64 years (29.8%), and those aged 65+ years (27.7%) in 2017-20 (i.e. a statistically significantly higher proportion for all of the older age groups than for those aged 15 to 24 years (13.0%), in both the 2014-17 and 2017-20 time periods).
The figure indicates that adult obesity in the Canterbury DHB region is associated with socioeconomic deprivation. The differences indicate that respondents (aged 15 years and over) who live in neighbourhoods that have the least deprived NZDep18 scores are less likely to be obese compared with respondents who live in neighbourhoods with the most deprived NZDep18 scores (for 2017–20, Quintile 1, 22.7%; Quintile 2, 23.8%; Quintile 3, 25.1%; Quintile 4, 26.2%; and Quintile 5; 31.3%). However, the differences are not statistically significant.
Source: Ministry of Health.
Survey/data set: New Zealand Health Survey to 2020. Access publicly available data from the Ministry of Health website https://minhealthnz.shinyapps.io/nz-health-survey-2020-21-annual-data-explorer/_w_0bb7535a/#!/explore-indicators
Source data frequency: Survey conducted continuously with data reported annually. Regional results (pooled data) released every 3 years.