What is the global impact of obesity?

Overweight or obese people now outnumber those who are undernourished by nearly two and a half times, a discussion paper of the McKinsey Global Institute, the business and economics research arm of global management consulting firm McKinsey and Company, has found.

The report states that more than 2.1-billion people – nearly 30% of the global population – are overweight or obese.

It also found that if the percentage of overweight and obese people continues to increase at its current rate, almost half of the world’s adult population will be overweight or obese by 2030.

But South Africa is already past the halfway mark: according to a 2014 study published in the Lancet, seven out of 10 women and four out of 10 men are overweight or obese.

These results correlate with a 2011 health survey conducted by pharmaceutical company GlaxoSmithKline that pronounced South Africa  “the third-fattest nation in the world” and a Medical Research Council study, which found that 61% of the South African population is overweight or obese.

In a press release this week – it’s national obesity awareness week – the Heart and Stroke Foundation South Africa said “one of the most worrying trends is the increase in overweight or obese children”. The  2013 South African National Health and Nutrition Examination Survey (SANHANES-1) found that the percentage of South African children between two and five years old who have significantly more body fat than what is deemed healthy has increased from 10.6% to 18.2% over the past decade.

Body fat

For adults, overweight and obesity ranges are determined using weight and height to calculate a person’s body mass index (BMI), which for most people correlates with the amount of body fat. According to Stellenbosch University’s nutrition department, “an adult who has a BMI of between 25 and 29.9 is considered overweight and when the BMI is 30 or higher the person is considered obese.”

Lisanne du Plessis, a human nutrition lecturer at the University of Stellenbosch, said children’s body fat rates are more complex to calculate as their age influences their scores. “Their BMI is calculated according to their length, weight and age, and the BMI is then interpreted from a BMI chart with pre-calculated percentiles,” she said. “The health department uses a tool, the  Road to Health booklet, that contains growth charts that are used to interpret children’s weight to height ratios.”

The Heart and Stroke Foundation pointed out that girls and female adults are consistently more affected by obesity. “South Africa further carries a double burden of malnutrition with not only rising rates of childhood obesity, but also still high prevalence of child undernutrition. Undernutrition places a child at especially high risk of developing obesity, which then promotes the vicious cycle that we are grappling with in the current socioeconomic environment.”

Risk of disease

Research has shown repeatedly that being overweight or obese increases one’s risk of heart disease and stroke, high blood pressure, diabetes and certain cancers. According to the foundation, “overweight or obese children have an increased risk of developing these diseases earlier in life and are more likely to remain obese throughout their adult life … Not only does obesity have far-reaching health effects for a child, but it also has vast social and economic implications. These can include bullying, teasing and low self-esteem, as well as increased healthcare costs and loss of income later in life.”

Heart and Stroke Foundation chief executive Vash Mungal-Singh said poverty, unhealthy diets and physical inactivity are largely to blame for the increase in obesity.

“Our children are being brought up in an obesogenic environment where unhealthy foods are aggressively marketed to them, time in front of computers and televisions is increasing and appropriate environments for children to be active, safely, are few and far between. With urbanisation, we have also seen an increase in the consumption of sugar-sweetened beverages, energy-dense, nutrient-poor foods and lower consumption of fruit and vegetables,” she said.

Poor feeding practices early in a child’s life have an impact on obesity. Studies have shown that there is a link between low birth weight and overweight later in life owing to overfeeding as an infant. The introduction of “weaning foods” too early – before six months of age – drives obesity later in life.

“Poverty has an overarching impact within this context. Lower income groups tend to have higher obesity rates as they opt for foods that are cheap and the most filling, which often means high in energy, fat, sugar and salt with very little other nutritional value. The pregnant mother and young child are most affected,” the foundation said.

This article is published in collaboration with Mail & Gardian. Publication does not imply endorsement of views by the World Economic Forum.

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Author: Mia Malan is the health editor and heads up the health journalism centre in Bhekisisa.

Image: An overweight woman sits on a chair. REUTERS/Lucas Jackson.