GWG, found that 97% of women gained weight below recommendations. The same study reported that 28% of women had infants with a normal birth weight and that the majority of women had LBW infants. The WHO classification and IOM guidelines for GWG according to pre-gravid BMI is summarised in table 2.2.
Table 2.2: WHO classification and IOM guidelines for gestational weight gain in pregnant women.
GWG category Recommended range of total weight gain (kg) Pre-pregnancy BMI
category
Inadequate Adequate Excessive Recommended weight gain (kg/week) BMI <18.5 (kg/m2),
underweight
<12.5 12.5–18 >18 0.45
BMI 18.5–24.9 (kg/m2), normal weight
<11.5 11.5–16 >16 0.45
BMI 25–29.9 (kg/m2), overweight
<7 7–11.5 >11.5 0.27
BMI ≥ 30 (kg/m2), obese <5 5–9.1 >9.1 0.20
Source: Tanaka et al (2014); IOM (2009)
The SANHANES-1, found that 45.6% of the South African population were food secure, 28.3% were at risk of hunger and 26.0% experienced hunger. The highest level of FI was found in urban informal dwellings (32.4%) and rural formal settlements (37.0%). High levels of being at risk for hunger was found in urban informal settlements (36.1%) and rural informal settlements (32.8%) (Shisana et al 2013). The leading causes of South African household FI include recurrent poverty and unemployment [Human Sciences Research Council (HSRC) 2007]. The provision of social grants has however, dramatically reduced household FI and hunger among South Africans (Altman & Jacobs 2010).
According to the United Nations Human Settlements Programme (UN-HABITAT), 61.7% of South Africans live in urban areas (The Centre for Development and Enterprise (CDE) 2005). Food access as a dimension of FS is dependent on the availability of income (Kennedy 2003). Food security in urban areas relies on residents having enough money to purchase food. Generally, those with a low income have to purchase smaller amounts of food (Kennedy 2003). This makes them vulnerable to FI (Van der Merwe 2011). Another component of FI in urban areas is food utilisation. In South Africa, eating patterns are generally influenced by ethnicity, culture and living in an urban or rural areas. In the past, urban black South Africans typically ate a low fat and high carbohydrate diet. However, many have undergone a nutrition transition resulting in a Westernised diet that is high in fat, protein, free sugars and low in fibre and carbohydrates. This shift in dietary habits is also linked to a lack of physical activity and the increased use of tobacco and alcohol (Van der Merwe 2011).
2.5.2 Household food security, dietary intake and gestational weight gain
According to the National Development Agency (2013) a quarter of South African women have malnutrition and vitamin deficiencies because of FI. Pregnant women are vulnerable to FI as they have greater nutrient requirements. They may also be less mobile or cannot access adequate amounts of food. Vulnerability increases especially during the third trimester and early postpartum stage (Natamba, Kilama, Arbach, Achan, Griffiths & Young 2014). In the USA, FI in women is associated with a higher BMI and hence a higher prevalence of overweight/obesity (Castell, Rodrigo, de la Cruz
& Bartrina 2015). Studies conducted in the UK, USA, Canada and Australia show that
FI in adults is associated with a low consumption of fruits and vegetables (Ihab, Rohana, Wan Manan, Wan Suriati, Zalilah & Mohamed Rusli 2013; Nelson et al 2007).
Food insecure pregnant women whose diets lack energy and micronutrients, have a greater likelihood of LBW infants. Mothers’ pass on their nutritional deficiencies to their infants. This can result in dire consequences for infants such as impaired growth and development (Ihab et al 2013).
Underweight and overweight can co-exist within an impoverished home (Ihab et al 2013). An American study reported that women from food insecure households had a pre-pregnancy BMI classified as morbidly obese. A possible explanation for this finding is that household FI can fuel the consumption of unhealthy appetising foods as a way to cope with stress (Laraia, Siega-Riz & Gundersen 2010). Household FI can result from dependence on reasonably priced energy-dense, mainly starchy foods. During late pregnancy it may be difficult for a woman to buy food and prepare it herself.
Hence, pregnant women may turn to eating inexpensive non-nutritious foods. As a result, women who are food insecure would seemingly have high GWG due to unhealthy eating habits (Laraia, Epel & Siega-Riz 2013).
2.5.3 Household food insecurity and depression in pregnant women
Food security and stress (depression) are important environmental predictors of maternal health and the prevalence of LBW (Mozayeni, Motlagh, Eshraghian & Davaei 2014). The major factors that influence FI and depression during pregnancy are unwanted pregnancies, low earnings, unemployment and low education level (Mozayeni et al 2014). One study reported that 66.9% of food insecure mothers’
suffered from depression (Mozayeni et al 2014). Another study reported that 32.9% of mothers’ suffered from depression, of those who were depressed, 67.1% were food insecure (Casey, Goolsby, Berkowitz, Frank, Cook, Cutts, Black, Zaldivar, Levenson, Heeren & Meyers 2004). Food insecure households in rural Malaysia have a greater probability of adults within households that suffer from nutrient deficiencies, morbidity, mental health problems, chronic diseases of lifestyle and elevated levels of depression (Ihab et al 2013; Laraia et al 2010). In South Africa, there seems to be a lack of published research that have investigated both household FI and depression in pregnant women.
2.6 Socio-economic status, food insecurity, dietary diversity and pregnancy