At that time he proved, both clinically and with the support of the second law of thermodynamics, the entropy law. It is not the caloric energy of food but rather the quantity of energy contained by food which is crucial to keep in good health and to recover.
He also explained that the energy of raw vegetal living cells is similar to sunlight, and called these vegetal cells light accumulators. Later he divided them in four categories, according to their biologic affinity to photosynthesis. These four categories became the basis of his dietetics.
In the course of the 20th century, it became possible to measure light accumulation and prove that solar light photons are accumulated by living cells -as happens with a laser. This luminous effect activates enzyme systems much more than caloric energy (by a factor of 1030). In his global therapy scheme, Dr Bircher-Benner submitted exactly to Nature's conditions and succeeded in obtaining therapeutic results which had never achieved up to then with incurable diseases. In 1937 he declined the appointment of Professor Ordinarius in Berlin's Hess Hospital (for political reasons).
The Bircher-Benner Clinic has welcomed patients like Tsar Nicolas II, Sir Stafford Cripps (former UK Chancellor of the Exchequer), Israeli Prime Minister Golda Meir, Tunisia President Habib Bourguiba, Rainer Maria Rilke, Thomas Mann, Hermann Hesse, Geza Anda, Yehudi Menuhin, Helena Rubinstein and many other well-known figures. Among Dr Bircher-Benner's friends were Dr and pedagogue Maria Montessori, Dr Auguste Forel, and Sigmund Freud (whom he viewed critically after his very different interpretation of the Oedipus complex, in his book “Der Menschenseele Not” (The pain of the soul), psychiatrist C.G. Jung and the Swiss poet Carl Spitteler. In his capacity of doctor researcher engaged in ethics, from a human and scientific point of view, Dr M. Bircher-Benner discovered the considerable effect of the raw vegetable s vital diet. In 1905 he published his first dietetic theory, which was well received.