Author Affiliations: The Cooper Institute, Dallas, Tex.
The modern living environment in developed countries is characterized
by low daily energy expenditure and an abundant and inexpensive food supply,
making positive energy balance common. The result is a rightward skewing of
the body mass index (BMI) distribution and an increasing prevalence of obesity.
Indisputable evidence links obesity to health problems, including risk
of cardiovascular disease, type 2 diabetes, some cancers, and all-cause mortality.1 These associations are dose-related, temporally consistent,
and biologically plausible, which support a causal hypothesis. Physical inactivity
also has a dose-related, temporally consistent, and biologically plausible
relationship to the same health outcomes as those as for obesity,2 and both obesity and inactivity have similar patterns
of association with clinical risk indicators such as blood pressure, fasting
plasma glucose, and inflammatory markers.3- 5 Furthermore,
declines in average daily energy expenditure are a likely underlying cause
of the obesity epidemic.6
Blair SN, Church TS. The Fitness, Obesity, and Health EquationIs Physical Activity the Common Denominator?. JAMA. 2004;292(10):1232–1234. doi:10.1001/jama.292.10.1232