"South Africa has the highest overweight and obesity rate in sub-Saharan Africa," the study showed.
"Seven in 10 women (69.3 percent) and four in 10 men (38.8 percent) are overweight or obese. For South African children, a fifth of boys and a quarter of girls are overweight or obese; seven percent of boys and 9.6 percent of girls are obese."
The Lancet released a new study from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington. The study examined obesity trends from 188 countries over more than 30 years.
In the study, overweight is defined as having a Body Mass Index (BMI), or weight-to-height ratio, greater than or equal to 25 and lower than 30, while obesity is defined as having a BMI equal to or greater than 30.
According to the results, nearly 30 percent of people worldwide, about 2.1 billion, are either overweight or obese.
The study showed that since 1980, not one country has successfully decreased its rate of obesity, while the rise in global obesity rates have been "significant, rapid and widesperead".
Since 1980, obesity and overweight had increased by 27.5 percent in adults and 47.1 percent in children.
Worldwide, 3.4 million deaths were caused by obesity in 2010, most from cardiovascular causes.
"Health risks such as cardiovascular disease, cancer, diabetes, osteoarthritis, and chronic kidney disease increase when a person's BMI exceeds 23," the study read.
"Research indicates that if left unchecked, the rise in obesity could lead to future declines in life expectancy."
Southern sub-Saharan African ranks among the highest regions in the world in the world percentage-wise for women who are overweight or obese.
The study found that globally the number of overweight and obese people increased from 857 million in 1980 to 2.1 billion in 2013.
The highest proportion of the world's obese people, 13 percent, live in the United States, while China and India together represent 15 percent of the world's obese population.
The rates in the study were adjusted for differences in population size and ages over time across the countries.
Between 1980 and 2013, the prevalence of overweight and obese children and adolescents increased by nearly 50 percent.
According to the study, more than 50 percent of the world's obese live in 10 countries -- United States, China, India, Russia, Brazil, Mexico, Egypt, Germany, Pakistan and Indonesia.