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RESEARCH ARTICLE
SA JOURNAL OF DIABETES & VASCULAR DISEASE
18
VOLUME 16 NUMBER 1 • JULY 2019
Ellisras Longitudinal Study 2017: The relationship
between dietary intake and body mass index among
young rural adults in South Africa aged 18 to 30 years
(ELS 18)
Julia TM Mashiane, Kotsedi D Monyeki, Andre P Kengne, Nkwana M Rosina,
Mafoloa S Monyeki
Correspondence to: Kotsedi D Monyeki
Department of Physiology and Environmental Health, University of Limpopo,
Sovenga, South Africa
e-mail:
kotsedi.monyeki@ul.ac.zaJulia TM Mashiane, Nkwana M Rosina, Mafoloa S Monyeki
Department of Physiology and Environmental Health, University of Limpopo,
Sovenga, South Africa
Andre P Kengne
Non-Communicable Diseases Research Unit, South African Medical Research
Council and University of Cape Town, Cape Town, South Africa
Previously published in
Cardiovasc J Afr
2018;
29
: 301–304
S Afr J Diabetes Vasc Dis
2018;
15
: 18–21
Abstract
Aim:
To assess the relationship between dietary intake and
adiposity in young rural South African adults.
Methods:
A total of 728 young adults participated and dietary
intake was assessed using the 24-hour recall method. Linear
regression models were used to determine the association
between dietary intake and body mass index (BMI) before
and after adjustment for age and gender.
Results:
Females showed higher mean BMI values than
males in all age groups. An age group of 27- to 30-year-old
females had a mean value of 28.1 kg/m
2
while males had a
mean value of 21.9 kg/m
2
. The distribution of BMI categories
(underweight, normal weight, overweight, obese) was 20.5,
61.7, 9.3 and 3.1% in males, and 8.6, 42.5, 23.1 and 25.8% in
females (p ≤ 0.05). Cholesterol intake was significantly (
p
≤
0.05) associated with BMI (beta = 0.002, 95% CI: 0.00–0.004)
as well as overweight and obesity (odds ratio = 1.734; 95%
CI: –1.09–2.75) after adjustment for age and gender.
Conclusion:
There was a high prevalence of overweight and
obesity among rural Ellisras females. Moreover, increasing
cholesterol intake was associated with overweight and
obesity in the overall sample.
Keywords:
dietary intake, body mass index, adults, overweight
and obesity
The prevalence of obesity continues to increase at an alarming rate
worldwide, with approximately two billion people being overweight
and one-third of them obese.
1
Over-consumption of macronutrients
contributes to overweight and obesity among the adult population.
2
A diet characterised by a decrease in dietary fibre and an increase in
saturated fats, accompanied by a lack of physical activity, results in
weight gain.
3,4
This is the result of a positive energy balance, where
energy intake is higher than energy expenditure.
2
Traditional eating habits of South Africans residing in rural areas
consist mostly of a prudent diet, which is associated with a low
prevalence of overweight and obesity.
5-8
However, the shift towards
a Western diet has become apparent among rural Africans,
increasing their likelihood of having modifiable risk factors for
chronic diseases of lifestyles, which include physical inactivity,
increased alcohol consumption, stress and smoking.
5
Preliminary results from the Ellisras cohort study showed a
significant association between intake of mono-unsaturated
fats and body mass index (BMI) among rural Ellisras children.
9
Furthermore, Sekgala
et al
.
10
reported a potential link between
dietary fibre intake and fasting blood glucose and high-density
lipoprotein cholesterol levels with both systolic and diastolic blood
pressure among young rural Ellisras adults. With the Ellisras sample
reaching the young adult stage, the relationship between BMI and
dietary intake has received little attention. This cross-sectional study
aimed to investigate the relationship between dietary intake and
BMI among young rural Ellisras adults aged 18 to 30 years.
Methods
This study is part of the ongoing Ellisras longitudinal study (ELS),
of which the details of the sampling procedure and geographical
area were reported elsewhere.
11
The subjects participating in this
cross-sectional study included 728 young adults (356 males and
372 females), aged 18 to 30 years, who are part of the Ellisras
longitudinal study (ELS).
The ethics committee of the University of Limpopo granted
ethical approval prior to the survey. The participants were provided
with informed consent forms and signed the form after receiving
verbal assent from the project leader.
All participants underwent a series of anthropometric measure-
ments according to the standard procedures recommended by the
International Society for the Advancement of Kinanthropometry
(ISAK).
12
Weight was measured on an electronic scale to the
nearest 0.1 kg, with light clothing and without shoes. Martin
anthropometric was used to measure height, to the nearest 0.1
cm, with no shoes. BMI was defined as weight (kg)/height (m
2
).
All participants were classified as underweight, normal, overweight
and obese, according to World Health Organisation cut-off points
for adults.
13
Diet was measured using the 24-hour recall method, which is
a valid method to determine group dietary intake.
14
In December