ABSTRACT
Unequal food systems and unhealthy diets prevail in a world with increasing nutritional inequities across a distinct social gradient. Although stocks of food have fallen recently, global food production per capita has risen steadily since the 1960s, and yet over 900 million people are undernourished and living in hunger (FAO, 2008). At the same time, the world has become fatter. Ultimately, individuals become obese if they consume more energy than they expend. Genes, while playing an important role in individual susceptibility (Khamsi, 2007), cannot explain the shifting societal-level patterns over the acute time period in which the global ‘obesity epidemic’ has occurred. A nutrition transition towards diets of highly refined foods, and of meat and dairy products containing high levels of saturated fats, occurred in the developed world around the mid-20th century and is increasingly evident in developing countries. For example, in countries such as South Africa, Egypt and Mexico, numbers of overweight and obese people have reached around 60 per cent in urban adult populations (Mendez et al, 2005). The global nutrition transition, together with marked reductions in energy expenditure through physical inactivity, is believed to have contributed to the rise in levels of obesity (Friel et al, 2007).
