Commentary: Current perspectives on obesity and health: black and white, or shades of grey?

Obesity has become one of the most discussed issues of our time. An Internet search on August 12, 2005 yielded 753 000 hits for ‘obesity epidemic’ and 9 680 000 hits on ‘obesity and health’. These numbers lag behind ‘relationships’ with 99 100 000 hits, but are impressive nonetheless. Campos et al. 1 focus on whether or not the emphasis on obesity as a public health problem is warranted or whether it represents alarmist claims that are not well supported by current data. To make our position clear at the outset, we believe that (i) obesity is a public health problem, (ii) the health hazards of obesity have been overstated and a mismatch exists between the strength of empirical evidence for obesity as a health risk and the intensity and amount of attention this issue receives in the scientific and lay press, (iii) most of the large prospective studies on obesity and health outcomes (e.g. mortality or non-fatal incident disease) fail to account adequately for a major confounder of this association—physical activity, and (iv) the focus should not be on obesity per se but on poor diet and physical inactivity, which are the principal lifestyle factors leading to obesity. These themes will appear throughout this report as we comment on each of the four major points discussed by Campos et al.