By Paula Erizanu

CNN

(CNN) -- The South African government is planning to implement a sugar tax to help curb the country's growing obesity epidemic.

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.

"What South Africa is experiencing is probably not that different from what the UK, USA and other high-income countries have gone through for many years. It's very much that kind of urban, Western kind of lifestyle," he added. "But in places like South Africa, the change is very rapid."

Women disproportionately more affected

Another unique point about the epidemic in South Africa is that women are disproportionately more affected.

In 2013, 40% of women in South Africa were obese, in contrast to a rate of just 12% among men.

"It's the cultural aspiration that bigger is better," Norris continued.

"It's been a longstanding cultural element on the African continent. In decades past, someone being fat was a good indicator of health, wealth and happiness. That aspect of deception is still prevalent in South Africa. "

Older women and men view fuller women as being better, so that is part of what may drive people's behavior, and it probably starts in early childhood, Norris said.

But he added that this "is certainly changing in the younger generation."

Norris further argued that girls also gain more weight during their teenage years due to a combination of factors.

"Women, particularly as they enter adolescence, drastically reduce levels of physical activity, and that sets a pattern to become more inactive adults than males."

"There are fewer opportunities for young women to engage in informal sport activity than there is for young men. Also, a lot of women are also more self-conscious about their bodies."

Will a tax on sugary drinks have an effect?

With cultural norms and the marked difference in sports participation among the genders, will a sugar tax actually help South Africans lose weight?

Potentially, but not in isolation.

The sugar tax is part of a wider plan by the South African government to prevent and control noncommunicable diseases, such as obesity and diabetes, over the next five years.

Alongside other WHO member states, South Africa has committed to reduce premature deaths from noncommunicable diseases by 25% by 2025 and by one-third by 2030, the latter target in line with the Sustainable Development Goals.

Other interventions the government is planning include nutrition labeling, marketing restrictions on unhealthy foods and beverages to children, fruit and vegetable subsidies, physical activity policies and social marketing campaigns.

"The tax will certainly make people more aware of the problem," Norris said.

"The tobacco tax example is a very effective legislation policy of how that started around taxation and then expanded through various policies around advertising and smoking restrictions in public."

Norris believes taxation resulted in significant reduction in tobacco uptake in South Africa and many places around the world.

"There's not one magic bullet that will deal with obesity effectively. It has to be a multipoint, multicentral solution."

CNN's Henrik Pettersson contributed to this report.