After broadly classifying South Africans into either underweight (BMI < 18.5), normal (BMI between 18.5 and 25), overweight (between 25 and 30) and obese (BMI > 30), and using accumulated waist circumference (WC) data, several alarming results were uncovered.
- In both sexes, BMI and WC increased significantly between 1998 and 2017.
- The increase was higher among women; and
- Increases in WC were not completely explained by increases in BMI.
In women, average weight increased from 67.7kg in 1998 to 72.6kg in 2017. In men the average weight increased from 65.5kg to 69.3kg during the same time period. There was an estimated 2.6cm increase in WC per decade among women, and a 2cm increase in men. If one looks only at the BMI definitions of obesity, the percentage of women who could be classified as obese increased from 29.5% in 1998 to a whopping 39.2% in 2017.