Cape Town. Picture: ISTOCK
Cape Town. Picture: ISTOCK

Cape Town residents may be the slimmest in the land and buy the healthiest food, but barely half of them are at a healthy weight, according to the latest "obecity" index released by Vitality, the incentive scheme managed by the country’s biggest medical scheme administrator, Discovery Health.

Only 53.5% of Capetonians had a healthy weight, a marginally better result than Johannesburg’s, where 52% made the grade. Bottom of the pile was Port Elizabeth, where only 48.8% of its residents had a healthy weight. The assessment was based on body mass index (BMI) and waist circumference.

Vitality’s report adds to a growing body of research showing that South Africans eat too little fruit and veggies, far too much sugar and salt, and all too readily turn to convenience food instead of preparing meals from scratch. It also highlights the extent of obesity in the middle classes, despite the choices available to them, said Vitality head Vitality Craig Nossel.

That SA has a rising proportion of obese people does not just raise their risk of life-threatening conditions such as diabetes and heart disease, but also places an increasing economic burden on the state, medical schemes and life insurers.

Overweight or obese people incur an increase in healthcare costs of about R4,400 a year, according to Vitality.

However, there is some good news in the study — it found that Vitality members who bought healthy food had a 10% lower BMI than people who did not, and that this purchasing behaviour was associated with up to R2,500 in lower annual health costs.

These results highlight the return on investment from Vitality’s pioneering rewards model, which draws on behavioural economics to nudge its members towards a healthier lifestyle with incentives such as cheap gym membership, discounts on fitness gear, and cash-back offers on healthy food items.

The results were reviewed by several academics, including Barry Popkin of the University of North Carolina, who said the reductions in BMI associated with purchasing less junk food had important implications, as the changes set people on long-term healthier eating trajectories that promised even greater effects. The study drew on data collected from just fewer than 500,000 Vitality members during 2016. It included information on weight and waist circumference, as well as the contents of their shopping trolleys at Vitality’s retail partners Pick n Pay and Woolworths.

The study also found that Durban dwellers bought fewer salty and sugary products than residents in other cities.

People in Johannesburg bought the most salty products, while Bloemfontein residents appeared to have the sweetest tooth, buying 40% more sugary foodstuffs than those in Durban.

kahnt@businesslive.co.za

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