It has long been accepted that the health status of a population is dependent on many inter-connected factors. Environmental, socio-economic and political influences are all associated with attaining health. This study has looked at the impact of nutrition (DES, protein, carbohydrate and fat intakes) on IMR and undernutrition in children and in overnutrition in adults
One of the most important findings of this SSA study is the significant relationship between IMR with exclusive breastfeeding and available protein intake shown in the multiple regression analysis. Stunting, DES and PPP were not significant predictors of IMR, despite them being significant in the univariate analysis. It appears that the strong relationship between IMR and these variables were by chance, and once confounding was controlled for, the significant associations disappeared.
Indeed, the regression analysis in the current study showed exclusive breastfeeding to be significantly associated with IMR, even though it was insignificant in the univariate analysis. It is disheartening to know that only a small prevalence (33.6 ± 20%) of mothers in SSA countries chose to breastfeed exclusively, despite the abundance of strategies directed at promoting exclusive breastfeeding in the continent. This prevalence is corroborated by those of WHO  that reported a finding of 30% in SSA. Breast milk is always the best, especially in a continent that grapples with high levels of food insecurity, poverty and HIV/AIDS infections. Breast milk provides just the right blend of proteins, fats, carbohydrates, minerals, and calories. Furthermore, it contains antibodies, which help protect the baby from infections and diseases [20–22]. As such, the results of the current study have important implications for policy-makers in Africa, as it emphasizes the importance of exclusive breastfeeding in the prevention of infant mortality.
The current study also highlights the fact that many countries in SSA have at least a reasonable available intake of protein (> 10% of total DES) and fat (> 20% of total DES) . The amount of protein consumed seems to be an important predictor for IMR in the current analysis. Indeed, results outlined in Figure 1a suggest that those individuals residing in DRC, Liberia and Guinea-Bissau consume the lowest amount of energy from protein, while at the same time having the highest levels of infant mortality (Table 2). Moreover, according to Earl and Borra , populations consuming 24-44 g of protein may not be getting enough essential amino acids. Amino acids are indeed crucial in the growth of infants; issues that have been stressed in child health for decades. Clearly, health workers in SSA need to prioritise strategies directed at emphasizing the importance of protein in the infants' diets as well as the promotion of exclusive breastfeeding for at least 6 months if the IMR is to be reduced.
The mean intake of 18.9 ± 5% of the overall DES from fat in the current study poses concern. Thirteen to 24 g of fat is equivalent to at least 2.5 to 5 teaspoons of fat. These levels are very low when compared to the recommended daily allowance of at least 65 g for adults and children over 4 years [20, 21]. As such, those individuals (especially children) consuming small amounts of fat may not be getting enough essential fatty acids to sustain their daily needs. It is therefore not surprising that countries at the lower extremes of total fat intake (Burundi with 13.4 g and DRC with 24.3 g) also presented with high IMR of 102 and 126, respectively.
The fourth Millennium Development Goal (MDG) is to reduce child mortality. One of the indicators used to measure progress is the IMR , which is a commonly used indicator of a population's economic and social development . Despite developing countries experiencing a decline in infant mortality during the last century, the results of the current study clearly show that the prevalence of undernutrition and infant mortality in SSA is still unacceptably high. These results are corroborated by other studies [25–27]. Moreover, according to Chopra and Darnton-Hill , the proportion and number of undernourished children in SSA has increased during the last 10 years.
Findings from this study indicate that the IMR in SSA ranges from as low as 24 to as high as 130 deaths per 1000 live births, while the percentage of stunted children range from 20% to 63%. Countries with the highest nutrition transition scores were found to have relatively low levels of IMR, stunted children and underweight-for-age. Despite some countries having lower levels than others, the percentage of children that are stunted and underweight-for-age in SSA as a whole, is still disappointingly high. From these results we conclude that countries experiencing the nutrition-related NCD phase of the transition, while experiencing high levels of obesity, are also experiencing a decline in rates for infant mortality and children that are stunted and underweight-for-age.
To speed up the reduction of infant and child mortality in SSA, countries need to allocate money to improving mother and child health care services and train health workers to detect and treat malnutrition related conditions as early as possible. Furthermore, improving the nutritional status of pregnant women will improve fetal growth which may lead to better health implications for many children .
Findings of the current study also show that RSA, Ghana, Gabon and Cape Verde had the highest nutrition transition scores. These countries with their relatively low levels of IMR and underweight, and relatively high levels of obesity/overweight, energy and fat intakes display classic signs of a population well established in the nutrition-related NCD phase of the nutrition transition.
However, countries with a high prevalence of obesity/overweight among women (Swaziland, Cameroon, Lesotho, and Sao Tome and Principe) were also found to have a moderate prevalence of children that are stunted (29-45%), a low prevalence of children that are underweight-for-age (6-17%), and nutrition transition scores of two and three. These findings confirm the prevalence of the dual burden household . While the dual burden household appears to be prevalent throughout SSA, its prevalence is especially high in countries undergoing the receding famine stage of the nutrition transition. This is further supported by their average energy and fat intakes.
Findings show that more than half of the countries (n = 26) evaluated in this analysis had nutrition transition scores of zero and one. Most of them had a high prevalence of children that are stunted or underweight-for-age, small percentages of women that are overweight and obese, and low intakes of energy, protein, and fat. In addition, their IMR are moderate to high, and in most of these countries more than 50% of the population live on less than one dollar per day. These countries are still in the receding famine stage of the nutrition transition. This implies that within the next few years they can be expected to move into stages 3-5 with their typical pattern.
Since stunting and undernutrition during childhood is associated with obesity during adulthood , the co-morbidities related to obesity are bound to increase in countries still in the early stages of the transition. This will result in their moderate NCD mortality levels rising dramatically. As such, endorsing strategies directed at reducing food insecurity in these countries will directly reduce the prevalence of stunting and at the same time indirectly reduce the prevalence of chronic non-communicable diseases.
The scoring system developed and used in the analysis of this paper has attempted to identify each country's stage in the nutrition transition. This system has the potential to be applied to other developing countries, thereby identifying their stage in the transition and being able to predict areas of concern that are most in need of assistance.