As stated earlier, this book was not intended to be about obesity. Nevertheless, much of the interest now directed to human body fat derives from biomedical interest in elucidating the causes and consequences of excess body fat. What can an evolutionary perspective contribute to this issue?

Chapters 6 considered a variety of beneficial functions fulfilled by adipose tissue in human biology, whereas Chapters 7 to 9 explored possible selective pressures that may have impacted on adipose tissue and other traits during hominin and human evolution. Historically, a suite of traits has been considered fundamental to human evolution. These traits include bipedalism, encephalisation, manual dexterity, culture and language. More recent perspectives have emphasised the importance of human life history – our slow pattern of growth and our unusual pattern of parental care (Bogin 2001). I would suggest that body fat is no less important than these other traits, and indeed it is integrally related to several of them. On the one hand, energy reserves have played a key role in buffering biological functions from fluctuations in energy supply. This has been particularly important in relation to the large human brain, and potentially to our colonising reproductive strategy. On the other hand, energy reserves are more than simply a fuel depot; they contribute to the regulation of these functions including life history variability.