Dietary fibre alone does not fully explain the frequent association between greater intake of whole grains and reduced risk of disease in observational studies, and other phytochemicals or food structure may also play an important role. For all the observational evidence for the benefits of a whole-grain-rich diet, we have only limited knowledge of the mechanisms behind this reduction in disease risk, aside from the action of specific cereal fibres on reduction of blood cholesterol and the post-prandial glucose peak. Nutritional metabolomics, the global measurement and interpretation of metabolic profiles, assesses the interaction of food with the endogenous gene–protein cascade and the gut microbiome. This approach allows the generation of new hypotheses which account for systemic effects, rather than just focusing on one or two mechanisms or metabolic pathways. To date, animal and human trials using metabolomics to investigate mechanistic changes to metabolism on eating whole grains and cereal fractions have led to new hypotheses around mechanistic effects of whole grains. These include the role of cereals as a major source of dietary glycine betaine, a possible effect on phospholipid synthesis or metabolism, the role of branched-chain amino acids and improvements in insulin sensitivity, and the possibility that whole grains may have an effect on protein metabolism. These hypotheses help explain some of the observed effects of whole grains, although mechanistic studies using stable isotopes and fully quantitative measures are required to confirm these potential mechanisms.

Nutrition transition goes with industrialisation that fosters human development which is usually desirable, especially in developing nations. However, the health consequences of this development include high rates of preventable non-communicable diseases which are usually undermined in the quest for industrialisation. The goal of the present paper is to provide evidence-based information that will promote healthy lifestyle including healthy consumption pattern among urban dwellers. Relevant local and international literature was accessed and reviewed to harvest evidence-based information through the use of validated review guide in addition to observation from the field experience. Industrialisation promotes creation of more job opportunities and this facilitates proliferation of fast-food eateries in the cities. However, it was also observed that many of the available workplaces in urban areas are not health-promoting because employees have poor access to preventive health information and sensitisation to healthy lifestyle has been poorly considered. Ironically, weight gain among urban workers which may be linked with increased intake of high-energy foods and low participation in physical activities as a result of accessibility to many energy saving devices have been highlighted as some of the pull-pull factors that attract many people to the cities. Using the concept of health promoting workplace, the workforce in urban areas can be trained as agent of change in health-promoting lifestyle. Consumption of healthy indigenous foods through aggressive promotion of its health potentials should be seriously advocated through the use of existing structure of urban fast-food vendors who constitute a strong stakeholder in nutrition transition.

The nutrition landscape in West Africa has been dominated by the programmes to address undernutrition. However, with increasing urbanisation, technological developments and associated change in dietary patterns and physical activity, childhood and adult overweight, and obesity are becoming more prevalent. There is an evidence of increasing intake of dietary energy, fat, sugars and protein. There is low consumption of fruit and vegetables universally in West Africa. Overall, the foods consumed are predominantly traditional with the component major food groups within recommended levels. Most of the West African countries are at the early stages of nutrition transition but countries such as Cape Verde, Ghana and Senegal are at the latter stages. In the major cities of the region, children consume energy-dense foods such as candies, ice cream and sweetened beverages up to seven times as frequently as fruit and vegetables. Adult obesity rates have increased by 115 % in 15 years since 2004. In Ghana, the prevalence of overweight/obesity in women has increased from 12·8 % in 1993 to 29·9 % in 2008. In Accra, overweight/obesity in women has increased from 62·2 % in 2003 to 64·9 % in 2009. The age-standardised proportion of adults who engage in adequate levels of physical activity ranges from 46·8 % in Mali to 94·7 % in Benin. The lingering stunting in children and the rising overweight in adults have resulted to a dual burden of malnutrition affecting 16·2 % of mother–child pairs in Cotonou. The prevalence of hypertension has been increased and ranges from 17·6 % in Burkina Faso to 38·7 % in Cape Verde. The prevalence is higher in the cities: 40·2 % in Ougadougou, 46·0 % in St Louis and 54·6 % in Accra. The prevalence of diabetes ranges from 2·5 to 7·9 % but could be as high as 17·9 % in Dakar, Senegal. The consequences of nutrition transition are not only being felt by the persons in the high socioeconomic class, but also in cities such as Accra and Ouagadougou, where at least 19 % of adults from the poorest households are overweight and 19–28 % have hypertension. Concerted national action involving governments, partners, private sector and civil society is needed to re-orient health systems and build capacity to address the dual burden of malnutrition, to regulate the food and beverage industry and to encourage healthy eating throughout the life course.

In recent years, there has been a renewed interest in the role of dietary fibre in obesity management. Much of this interest stems from animal and human studies which suggest that an increased intake of fermentable fibre can suppress appetite and improve weight management. A growing number of reports have demonstrated that the principal products of colonic fermentation of dietary fibre, SCFA, contribute to energy homeostasis via effects on multiple cellular metabolic pathways and receptor-mediated mechanisms. In particular, over the past decade it has been identified that a widespread receptor system exists for SCFA. These G-protein-coupled receptors, free fatty acid receptor (FFAR) 2 and FFAR3 are expressed in numerous tissue sites, including the gut epithelium and adipose tissue. Investigations using FFAR2- or FFAR3-deficient animal models suggest that SCFA-mediated stimulation of these receptors enhances the release of the anorectic hormones peptide tyrosine tyrosine and glucagon-like peptide-1 from colonic L cells and leptin from adipocytes. In addition, the SCFA acetate has recently been shown to have a direct role in central appetite regulation. Furthermore, the SCFA propionate is a known precursor for hepatic glucose production, which has been reported to suppress feeding behaviour in ruminant studies through the stimulation of hepatic vagal afferents. The present review therefore proposes that an elevated colonic production of SCFA could stimulate numerous hormonal and neural signals at different organ and tissue sites that would cumulatively suppress short-term appetite and energy intake.

Nutrition transition is characterised by shift to highly refined diets high in fat, salt and caloric sweeteners and low in fibre in rapidly growing economies. Dietary shifts occur almost concurrently with demographic and epidemiologic shifts, urbanisation and industrialisation and together contribute to increased prevalence of nutrition related (NR)-non-communicable disease (NCR). The emergence of nutrition transition in Southern Africa countries (SAC) was examined using anthropometric, NCD prevalence, and food consumption data. The findings reveal growing prevalence of overweight and obesity (OWOB) across SAC, with national prevalence estimated between 30 and 60 % in all but two SAC. Overweight prevalence in excess of 60 % has been reported in some sub-population groups. Hypertension prevalence of at least 30 % has also been reported. Further, the prevalence of OWOB and hypertension in many SAC exceeds that of HIV and is often at par with stunting in children. NCD are equally serious public health problems as stunting and HIV. Collectively, NR-NCD explain 20–31 % of mortality for Botswana, South Africa, Swaziland, Mozambique and Zambia. At least 72 % of adults in SAC have fewer servings of fruit and vegetable servings daily than recommended. Additionally, adults in SAC do poorly in physical activity; 31–75 % do not exercise regularly. Not surprisingly, 15–40 % of adults in SAC have at least three risk factors of CVD. SAC are grappling with NR-NCD which threaten to surpass infectious diseases burden. SAC are at various levels in interventions for moving their populations to stage 5, but there is room for much improvement.

Presently, close to 1 billion people suffer from hunger and food insecurity. Statistics in Kenya indicates that over 10 million people suffer from chronic food insecurity and poor nutrition, 2–4 million people require emergency food assistance at any given time with nearly 30 % of Kenya's children being undernourished, 35 % stunted while micro-nutrient deficiency is wide spread. Key among the challenges contributing to inadequate foods include lack of certified seeds, seasonal production (rain-fed), high post-harvest losses and wastages, poor transportation, low value additions which reduce their market competitiveness. The present paper examines some of the underlying causes for high food wastage experience in Kenya and the associated challenges in addressing these problems. The paper also provides an overview of some of the basic solutions that have been recommended by various stakeholders. However, in spite of the recent efforts made to mitigate food wastage, there is still an urgent need to address these gaps through participatory, innovative community based interventions that will create resilience to climate change and enhance livelihoods of smallholder farmers in diverse ecosystems.