Dr. Elias Petrou, a Greek doctor and physiotherapist, came to Greece in 1935 from America where he studied. With a series of books he wrote and corresponding lectures, he managed to change Greek society in a few years. His actions, along with the treatments he provided to people suffering from serious or non-serious illnesses, in a few days and mainly in a natural way, made Greeks believe in him and talk about the new "revolution" of natural hygiene. The therapeutic methods he applied were based on the following:
- Fasting for detoxification and correction of intestinal function, from which most diseases originate according to natural hygiene and natural therapeutic science.
- Fruit therapy for natural toning of the body, treating many diseases and as a smooth re-entry into the diet after fasting.
- Alkaline diet for correction and rise of pH in the blood, as a preventive measure so that we do not get sick.
- Physical exercise for proper muscle function and elimination of toxins through burning in the body.
- Air therapy through exposure to clean environment and respiratory exercises.
- Sun therapy through exposure to the sun -obliquely in the shade and not directly- with measure but steadily throughout the year, in order to acquire the bronze color that is indicative of a healthy person as he said, (not the sickly color of the solarium, nor the excesses of the sun).