Dr. Ilias Petrou, a Greek doctor and physiotherapist, came to Greece in 1935 from America where he studied. Through a series of books he wrote and corresponding lectures, he managed to change Greek society within a few years. His own actions, with the treatments of people suffering from serious or minor illnesses within just a few days and mainly through natural methods, made the Greeks believe in him and speak of 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 arise according to natural hygiene and natural therapeutic science.
• Fruit therapy for naturally revitalizing the body, curing many ailments and also serving as a smooth re-entry into the diet after fasting.
• Alkaline diet to correct and raise the pH in the blood, as a preventive measure so that we do not get sick.
• Physical exercise for the proper functioning of the muscles and the elimination of toxins from the body through burning.
• Aerotherapy through exposure to a clean environment and respiratory exercises.
• Sunbathing through exposure to the sun -sidely in the shade and not directly- in moderation but consistently throughout the year, in order to acquire the bronze color that is indicative of a healthy person, as he said, (not the sickly one from the tanning bed, nor the excesses of the sun).