Are lifestyle shifts fuelling the obesity epidemic in urbanised Africans?

Humans evolved for active lifestyles involving hunting-gathering and agriculture. To sustain these energy-intensive lifestyles, diets consisting of energy-dense foods were selected. It can therefore be argued that humans are physiologically adapted for active lifestyles. However, with rapid industrialisation, there has been an upsurge in the usage of labour-saving devices as well as a glut in the supply of energy-dense foods. This mismatch between energy supply and expenditure in modern man may be fuelling the contemporary trends in obesity in urbanised man. On the other hand, recent emerging evidence indicates that air pollution related to motorised transportation in urban areas may be obesogenic by causing alterations in the lipid metabolic pathways, resulting in fat deposition. These lifestyle shifts are drastically different from traditional rural African lifestyles and mirror the different prevalence rates of obesity and related co-morbidities between rural versus urban areas.