In a major recent review of the causes of death in the USA,¹ Mokdad and colleagues found, unsurprisingly, that “smoking remains the leading cause of mortality”. The authors also concluded, notably, that “poor diet and physical inactivity may soon overtake tobacco as the leading cause of death.” The reaction to this news was swift, broad, curious, and instructive.

From around the globe, headlines screamed out variations on the theme: “Fat gains on tobacco as top death factor” (CNN)²; “Combating Killers: Fat, Tobacco” (CBS News)³; “Fat of the land is killing more Americans than cigarettes” (The Times, London)⁴; “Americans Eating Themselves to Death” (The Scotsman)⁵; “US government moves to reduce rampant obesity” (Taipei Times)⁶; “Obésité : le mal du siècle” (Le Figaro, Paris).⁷

Clearly, Mokdad’s study in JAMA sounded an alarm, but why, and what precisely was the message? Most newspaper reports, derived from Associated Press (AP) and other wire stories, merely reflected the tone set by a JAMA news release.⁸ News articles routinely explained that “poor diet and physical inactivity caused 400,000 deaths in 2000, a 33-percent jump over 1990” while tobacco related deaths “climbed by less than 9 percent”, meaning that “obesity will surpass tobacco if current trends continue”.

DISTORTION

Those numbers are correct, but their front page news spin creates a certain distortion. In fact, that 33% rise means that “gluttony and sloth” accounted for 16.6% of all US deaths in 2000 (400 000 out of 2.4 million) versus 14% in 1990 (300 000 out of 2.1 million), while smoking attributable mortality dropped just slightly from 19% …