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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 29, No 5, September/October 2018
AFRICA
301
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
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
Submitted 12/4/18, accepted 19/6/18
Published online 24/10/18
Cardiovasc J Afr
2018; 29: 301–304
www.cvja.co.zaDOI: 10.5830/CVJA-2018-033
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
measurements 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
Department of Physiology and Environmental Health,
University of Limpopo, Sovenga, South Africa
Julia TM Mashiane, BSc (Hons)
Kotsedi D Monyeki, PhD, MPH,
kotsedi.monyeki@ul.ac.zaNkwana M Rosina, BSc (Hons)
Mafoloa S Monyeki, MPhil
Non-Communicable Diseases Research Unit, South African
Medical Research Council and University of Cape Town,
Cape Town, South Africa
Andre P Kengne, MD, PhD, CRENC