Obesity has reached epidemic proportions in many countries and persists despite continuing efforts to find solutions. Such 'stubborn problems' often signal the influence of 'feedback systems'. In the case of the obesity epidemic, this possibility can be investigated using available system analysis tools. The investigation must begin with a study of the interplay between the full range of human and environmental factors. This paper outlines the nature of feedback and briefly discusses some of its management implications. A practical way to initiate a 'systems approach' to the obesity problem is suggested and four principles to guide the management of complex human- environment systems are presented.