- The Daily Nation told Africa Check the figure “two in every five” was drawn from a 2014 demographic and health survey.
- The cited survey doesn’t show this. It only has data showing that 10.1% of surveyed women aged 15 to 49 were obese and 4.1% of children younger than five.
- Experts told us no other data available supported the figure quoted by the newspaper. They estimated one in 10 adults and far fewer children were obese.
“Obesity – a condition that affects two in every five Kenyans – has been implicated in many of the hospitalisations and deaths,” the newspaper said.
It cited “preliminary research on African American deaths due to Covid-19 in France, the UK and the US” and comments from a health official and a scientist in support of this statement.
Guidelines from Kenya’s health ministry note that there are some risks when treating critical cases of Covid-19 in patients who have obesity.
But the Daily Nation did not give a source for its claim about the number of people who are obese. Are as many as 40% of Kenyans at greater risk from the virus? We investigated.
Paper’s source doesn’t show 2 in 5 figure
The journalist who wrote the article told Africa Check that the source of the figures was the 2014 Kenya Demographic and Health Survey.
The nationally representative household survey provides data on a wide range of topics, such as population, health and nutrition and is carried out in several countries.
The 2014 survey is the most recent on Kenya and has information on the nutritional status of women and children, but not men. It showed that from a sample of 13,143 women aged 15 to 49, some 10.1% were obese.
The survey reported 43% of women in urban areas were likely either obese or overweight. This was the closest figure in the survey to the “two in every five” reported by the Daily Nation.
The World Health Organization defines overweight and obesity as “abnormal or excessive fat accumulation that may impair health”.
The health agency says a measure known as the body mass index, or BMI, is commonly used to classify overweight and obesity in adults. It is calculated as “a person's weight in kilograms divided by the square of his height in metres (kg/m2)”.
In adults, if the BMI is 25 or more, they are overweight, and obese if the index is 30 or more. The WHO says that for children, age should be considered. This is because “it is difficult to develop one simple index for the measurement of overweight and obesity in children and adolescents because their bodies undergo a number of physiological changes as they grow”.
Children under five are considered overweight or obese if their weight-for-height is greater than would be statistically expected under WHO child-growth guidelines. Those aged five to 19 are overweight or obese if their BMI-for-age is more than would be be statistically expected under WHO growth references.
The second way of measuring obesity is the waist-hip ratio, Dr Gershim Asiki, research scientist at the African Population and Health Research Center in Nairobi, Kenya, told Africa Check. This is calculated by dividing the waist circumference by the hip circumference.
“The waist-hip ratio is more accurate than BMI in estimating obesity. It measures the accumulation of fat in your tummy,” Asiki, who leads the non-communicable disease research programme at the center, said.
“For men a value equal or more than 0.9 denotes obesity while among women a value 0.85 or more means you are obese.”
Survey shows adult estimate closer to 9%, not 40%
Dr Alice Mboganie Mwangi told Africa Check the 2014 demographic and health survey and a 2015 survey on non communicable diseases by Kenya’s health ministry were “the most comprehensive information we have currently”.
She is the head of the applied human nutrition programme at the University of Nairobi’s department of food technology and nutrition.
Dr Gershim Asiki, research scientist at the African Population and Health Research Center, said the 2015 health ministry survey was the most current for adults aged 18 to 69.
The survey was of 4,574 people, of whom 40% were men and 60% women. Using the WHO’s body mass index classification, it found that 4.3% of men and 13.7% of women were obese. For both sexes, 8.9% were obese, about one in every 10 people.
|Proportion of Kenyan men and women by BMI classification in 2015|
|Underweight (BMI under 18.5)||13.7%||8.9%||11.3%|
|Normal (BMI 18.5 -24.9)||68.8%||52.6%||60.8%|
|Overweight (BMI 25-29.9)||13.2%||24.9%||19.0%|
|Obese (BMI 30 and higher)||4.3%||13.7%||8.9%|
Source: Kenya Stepwise Survey for Non Communicable Diseases Risk Factors 2015 Report, Ministry of Health
The survey also gave estimates using the waist-hip ratio. It found that “28% of the men and 36% of the Kenyan women had a higher waist–hip ratio than recommended” and were at a higher risk of obesity-related illnesses. The survey did not give separate estimates for obesity and overweight.
The most recent data from the WHO using body mass index shows 6% of adult Kenyans were obese as of 2017. This was 2.5% of men and 9.4% of women.
What of children?
According to the 2014 Kenya demographic and health survey, 4.1% of children under five were considered overweight or obese.
Asiki said there isn’t national-level data yet for children aged under 18. But “there are pockets of small studies in some parts of Kenya for preschool children and school children”.
He said a 2010 study found obesity among 4% of preschool children aged three to five, and a 2014 study found 6% of children in Nairobi aged nine to 11 were affected.
Asiki said: “Even without the national figures we can predict that it is much lower among children”.
The WHO estimated that as of 2017 2.3% of Kenyan children aged five to nine were obese, and 1.7% of childen aged 10 to 19. We have asked the organisation for the source of its data.
The University of Nairobi’s Dr Mwangi said it was inaccurate that two in five Kenyans are affected by obesity.
“That’s not true, unless you want to differentiate in terms of location and gender. You might find more obesity in urban areas and also among more women than men. It’s not two in every five Kenyans, that’s not factual.”
Conclusion: Data doesn’t support claim that obesity affects two in five Kenyans
In seeking to highlight the increased risks Kenyans with obesity face from Covid-19, a national newspaper claimed that two in every five Kenyans are obese.
Experts told Africa Check that the most recent data does not support this. Approximately one in 10 adults in Kenya are obese, and while there isn’t national-level data available, the rate of obesity for children would be much lower.
We therefore rate the claim as incorrect.