It is undeniable that regular consumption of fast food can lead to serious health problems. However, most people agree that fast food companies should not be held liable for the effects their product has on the health of consumers. Few people, however, disagree with holding tobacco companies liable for the serious health problems caused by cigarette usage. Ttherefore, fast food must not be as unhealthy as cigarettes.
That health concerns are the only reason people believe tobacco companies should be held liable is assumed in the passage.