Overweight and obesity
Globally, overweight and obesity is a major public health concern, and there are more overweight or obese than underweight adults. In 2016, 39% men and 40% of women aged 18 and over, accounting for nearly 2 billion adults, were overweight, and 11% of men and 15% of women, more than half a billion, were obese worldwide. Both overweight and obesity have shown a marked increase over the past four decades (WHO, 2020[24]).
Obesity is a known risk factor for numerous health problems, including hypertension, high cholesterol, diabetes, cardiovascular diseases, respiratory problems (asthma), musculoskeletal diseases (arthritis) and some forms of cancer, and mortality also increases progressively once the overweight threshold is crossed (OECD, 2019[25]; WHO, 2020[24]). Furthermore, overweight, and obesity in particular, are found to be associated with higher risks of developing severe pneumonia and dying among COVID-19 patients (Qingxian et al., 2020[26]).
A key driver of the increasing obesity epidemic is a changing food environment, in which nutrient poor and energy dense processed foods are aggressively marketed, readily available and often cheaper than healthier alternatives. The economic priorities and policies that promote consumption-based growth, and the regulatory policies that promote market and trade liberalisation are increasingly regarded as contributing to the global rise of obesity too (OECD, 2019[25]; UNICEF, 2019[10]).
In Asia-Pacific, the obesity rate among children and adolescents varied widely between the high of 16.3% in New Zealand, followed by 14.1% in Brunei Darussalam, and the low of 1.7% and 2.0% in Nepal and India respectively, where the prevalence of underweight was high among adolescents (see indicator “Adolescent health” in Chapter 4). On average across high and upper-middle income Asia-Pacific countries and territories, over one in ten children and adolescents were obese in 2016, more than twice the prevalence observed across lower-middle and low income Asia-Pacific countries and territories. In New Zealand where the obesity rate is the highest in Asia-Pacific, the prevalence of overweight was also the highest in the region at almost 40%, whereas in India with one of the lowest obesity rates, the prevalence of overweight was lowest at less than 7% (Figure 4.15 right panel).
Among adults, obesity prevalence was high in Australia, Fiji and New Zealand in 2016 where almost one in three in adults were obese. In these countries and territories, the prevalence of overweight adults was also high at more than 60%. On the other hand, obesity rate was low in Bangladesh, Cambodia, India and Viet Nam at below 4%, and in India and Viet Nam, overweight prevalence among adults was also the lowest in Asia-Pacific, at less than 20%. In high and upper-middle income countries and territories, 15% of adults were obese and 43% of adults were overweight, whereas the average prevalence for lower-middle and low income countries and territories was lower at 9% and 31%, respectively (Figure 4.15, left panel). Across countries and territories, the prevalence of obesity and overweight among children and adolescents was positively associated with the prevalence among adults.
Between 2010 and 2016, the increase in the prevalence of obesity was fast particularly in lower-middle and low income countries and territories in Asia-Pacific. This increase was higher among children and adolescents in most countries and territories. In lower-middle and low income countries and territories, the prevalence of obesity increased on average by 61% among children and adolescents (from 2.7% to 4.4%) and by 28% among adults (from 6.8% to 8.7%). The average increase was lower in higher income countries and territories – by 14% among children and adolescents (from 9% to 10.2%) and by 16% among adults (from 12.8% to 14.8%). The increase was particularly high in Viet Nam, by 1.6 times among children and adolescents (from 1% to 2.6%) and by 50% among adults (from 1.4% to 2.1%). The obesity prevalence also doubled in India among children and adolescents (from 1% to 2%) and increased by over 50% among adults in Lao PDR (from 3.5% to 5.3%) (Figure 4.16).
Since 2010, the prevalence of overweight has increased in almost all Asia-Pacific countries and territories. The increase was again faster in lower-middle and low income countries and territories – 38% for children and adolescents (from 10.8% to 14.9%) and 15% for adults (from 26.9% to 30.8%) – than in high income countries and territories – 8% (from 25.4% to 27.3%) and 7% (from 40.7% to 43.4%), respectively. Between 2010 and 2016, the prevalence of overweight grew rapidly in Viet Nam among children, adolescents and adults. The prevalence also grew fast by 55% among children and adolescents in India (from 4.4% to 6.8%) and Cambodia (from 7.3% to 11.3%), and a significant increase was also observed among adults in Lao PDR (23%, from 20.6% to 25.4%), Thailand (22%, from 26.7% to 32.6%) and Bangladesh (22%, from 16.4% to 20%) in the same period (Figure 4.17). In developing countries obesity is more common among people with a higher socio-economic status, those living in urban regions and middle-aged women. In developed countries, obesity is associated with lower socio-economic status, especially among women (OECD, 2010[27])
The most frequently used measure of overweight and obesity is the Body Mass Index (BMI). This is a single number that evaluates an individual’s weight in relation to height, and is defined as weight in kilograms divided by the square of height in metres (kg/m2).
The WHO definition of child and adolescent overweight is a BMI greater than 1 standard deviation above the median, and the definition of child and adolescent obesity is a BMI greater than 2 standard deviation above the median.
Based on the WHO classification, adults with a BMI 25 or over are overweight and adults who have a BMI of 30 or over are defined as obese.
In many countries, self-reported estimates of height and weight are collected through population-based health surveys while in Australia, Japan, the Republic of Korea and New Zealand, health examinations measure actual height and weight. These differences limit data comparability. BMI estimates from health examinations are more reliable, and generally result in higher values than from self-report surveys.
Source: WHO GHO 2020.
Source: WHO GHO 2020.
Source: WHO GHO 2020.