Obesity and cancer third most important risk factor for cancer in the United States, just behind tobacco and diet (see Figure). Obesity is the source of about 15% of all preventable cancers. In 2018, Chinese researchers performed a systematic review and comprehensive quantitative meta‐analysis of cohort studies reporting body mass index (BMI) and the risk of 23 cancer types, providing epidemiological evidence supporting the association between BMI and cancer risk. The strongest positive association between BMI and cancer risk was found among patients in North America. The mechanisms by which obesity may increase the risk of cancer are not well understood, but it
Degrees of freedom (physics and chemistry) system is the sum of the average energies associated with each of the degrees of freedom: A degree of freedom is quadratic if the energy terms associated with this degree of freedom can be written as where is a linear combination of other quadratic degrees of freedom. example: if and are two degrees of freedom, and is the associated energy: For example, in Newtonian mechanics, the dynamics of a system of quadratic degrees of freedom are controlled by a set of homogeneous linear differential equations with constant coefficients. are quadratic and independent degrees of freedom if the energy associated with