Dr. Ilias Petrou, a Greek doctor and physiotherapist, came in 1935 from America where he studied, and with a series of books he wrote and corresponding lectures, he managed to change Greek society within a few years. His own actions, treating people suffering from serious or non-serious illnesses, within a few days and mainly in a natural way, made the 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 bowel function, from where most diseases originate according to the principles of natural hygiene and natural healing science.
• Fruit therapy for the natural stimulation of the body, healing many ailments and also as a smooth re-entry into diet after fasting.
• Alkaline diet for correcting and raising the pH in the blood, as a means of prevention so we do not get sick.
• Physical exercise for the proper functioning of the muscles and the elimination of toxins from the body through burns.
• Aerotherapy through our exposure to a clean environment and breathing exercises.
• Sunbathing through our exposure to the sun - laterally in the shade and not directly - in moderation but consistently throughout the year, in order to acquire the bronze color that indicates a healthy person, as he used to say, (not the sickly look from sunbeds, nor the excesses of sun exposure).