Francois Henri LaLanne was born in San Francisco, California, to French immigrant parents. During his childhood, he suffered from poor health, including symptoms that would later be identified as sugar addiction. He was often ill, suffering from headaches, boils, and a generally weak constitution. This early frailty would ironically fuel his later dedication to physical fitness.

At the age of 15, LaLanne attended a lecture by health guru Paul Bragg. Bragg's message about nutrition and exercise resonated deeply with the young LaLanne, providing him with a framework and the inspiration to transform his own life. He credits this moment as the pivotal turning point that set him on his path to health and fitness advocacy.