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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 6, November/December 2016
AFRICA
367
Determinants of change in body weight and body fat
distribution over 5.5 years in a sample of free-living
black South African women
Sarah Chantler, Kasha Dickie, Lisa K Micklesfield, Julia H Goedecke
Abstract
Objective:
To identify socio-demographic and lifestyle deter-
minants of weight gain in a sample of premenopasual black
South African (SA) women.
Methods:
Changes in body composition (dual-energy X-ray
absorptiometry, computerised tomography), socio-economic
status (SES) and behavioural/lifestyle factors were measured
in 64 black SA women at baseline (27
±
8 years) and after 5.5
years.
Results:
A lower body mass index (BMI) and nulliparity,
together with access to sanitation, were significant determi-
nants of weight gain and change in body fat distribution over
5.5 years. In addition, younger women increased their body
weight more than their older counterparts, but this associa-
tion was not independent of other determinants.
Conclusion:
Further research is required to examine the effect
of changing SES, as well as the full impact of childbearing on
weight gain over time in younger women with lower BMIs.
This information will suggest areas for possible intervention
to prevent long-term weight gain in these women.
Keywords:
body fat distribution, weight gain, black women,
South Africa
Submitted 10/12/15, accepted 22/3/16
Published online 25/5/16
Cardiovasc J Afr
2016;
27
: 367–374
www.cvja.co.zaDOI: 10.5830/CVJA-2016-038
Obesity and its co-morbidities continue to increase worldwide,
with women from low- and middle-income countries (LMICs)
being most affected.
1
Within South Africa, the prevalence of
overweight/obesity has increased from 56.2 to 64.8% in the
most recent South African National Health and Nutrition
Examination survey (SANHANES),
1,2
confirming the problem
within South Africa.
Our study in a cohort of black South African (SA)
women reported a 9% increase in body weight over a 5.5-year
period.
3
The weight gain was attributed predominantly to an
increase in fat mass, which was greatest in central compared
to peripheral depots. The relative redistribution of body fat
was associated with increases in fasting plasma glucose and
triglyceride concentrations, with reduced insulin sensitivity and
a compensatory increased insulin secretion at follow up.
3
Other longitudinal studies measuring changes in body
composition over time reported weight gain that ranged from
0.5–0.9 kg/year.
4-7
However, these studies were undertaken in
high-income countries (HICs). These data are valuable since to
the authors’ knowledge, there are no known longitudinal studies
from populations living in LMICs.
Determinants of weight gain in these studies include
non-modifiable factors such as age, gender and race, and
modifiable factors such as baseline body mass index (BMI),
5
dietary intake,
4,7-9
physical activity,
10
socio-economic status
(SES)
11,12
and parity.
13-15
Associations between these factors are
often complex in nature, and it is difficult to draw conclusions
regarding the relative contribution of these factors to increasing
body weight in different populations. Furthermore, many of
these studies failed to assess the impact of these determinants
on changes in body composition or body fat distribution. Due
to the risk of cardiometabolic disease associated with increasing
total and central fat mass,
16-18
and the possible protective benefits
associated with peripheral fat mass,
19
a greater understanding of
the determinants of body composition changes are important to
inform future intervention studies.
In addition, within LMICs, other factors such as
urbanisation and the ‘transition’ from a traditional to a more
westernised lifestyle have been associated with obesity and other
non-communicable diseases.
20
The relationship between SES
and obesity in LMICs differs from that in HICs, with studies in
LMICs reporting a positive association between SES and BMI,
with the inverse association being reported in HICs.
21
To our
knowledge no longitudinal studies have assessed the impact of
change in SES on body composition and body fat distribution.
Therefore, the aim of this study was to assess lifestyle factors
and SES variables at baseline and the changes in these factors
over a 5.5-year follow-up period, and how these are associated
with changes in body weight and whole-body fat distribution in
a sample of peri-urban free-living black SA women.
Division of Exercise Science and Sports Medicine,
Department of Human Biology, University of Cape Town,
Cape Town, South Africa
Sarah Chantler, MSc
Kasha Dickie, MSc
Lisa K Micklesfield, PhD
Julia H Goedecke, PhD
Non-Communicable Disease Research Unit, South African
Medical Research Council, Cape Town, South Africa
Julia H Goedecke, PhD,
julia.goedecke@mrc.ac.zaMRC/Wits Developmental Pathways for Health Research
Unit, Department of Paediatrics, Faculty of Health
Sciences, University of Witwatersrand, Johannesburg,
South Africa
Lisa K Micklesfield, PhD