The problem reflects the global increase in obesity and overweight rates across developing countries, surpassing the rate of obesity in developed states.
The number of overweight and obese people in the developing world has grown from 250 million in 1980 to a billion in recent years, according to the Overseas Development Institute.
In tackling sugar drink prices, South Africa follows in the footsteps
of Mexico, France, Hungary and New York, which have pioneered the strategy.
It plans to introduce a 20% tax on soft drinks that will come into force April 1, making South Africa, which has one of the highest rates of obesity on the continent, the first African country to adopt the measure.
Soft drinks have "become part of the national diet"
The consumption of soft drinks has steadily increased in South Africa over the past 50 years.
In a parliamentary debate on the issue, professor Tolullah Oni of the University of Cape Town said that on average, a South African had consumed 254 Coca-Cola-type drinks in 2010, compared with the global mean of 89.
"Sugar-sweetened beverages are marketed and sold everywhere in the country," said Dr. Rufaro R. Chatora, the World Health Organization representative for South Africa.
"The marketing messages say it's a good thing to drink these beverages but do not say anything about the risks. So these beverages have become part of the diet and this contributes to the development of obesity."
Urbanization to blame?
South Africa's fast urbanization may be one of the reasons for the rise in the consumption of processed foods and soft drinks.
"Sedentary behavior also increases; there's more transport accessibility; people walk less; there are more built environments," said Shane Norris, professor and director of the Medical Research Council's Developmental Pathways for the Health Research Unit at the University of Witwatersrand, Johannesburg.