Francois Henri LaLanne, the "Godfather of Fitness", was an American fitness and nutrition guru and motivational speaker. He described himself as being a "sugarholic" and a "junk food junkie" until he was 15 years old. He also had behavioral problems but "turned his life around" after listening to a public lecture about the benefits of good nutrition by health food pioneer Paul Bragg. During his career, he came to believe that the country's overall health depended on the health of its population, and he referred to physical culture and nutrition as "the salvation of America".

Paul Chappuis Bragg was an American alternative health food advocate and fitness enthusiast. Bragg's mentor was Bernarr Macfadden. He wrote on subjects such as detoxification, dieting, fasting, longevity, orthopathy and physical culture. Medical experts criticized Bragg as a food faddist and promoter of quackery.