Against a backdrop of social issues, natural resource limits and waste problems, the question of how people live and consume - the lifestyles they pursue - becomes central to sustainability. The continuing increase in population in Asia, Africa and Latin America needs to sustain itself, in a fast growing economic environment, the level of material consumption per person also increases. For example, according to the African development Bank (AtDB 2011), there was a growth rate of 3.1% in the middle-class (defined as those consuming between 2-20 USD per day) in Africa, rising from 126 million people (27%) in 1980 to 350 million (34%) in 2010.