In 2011, Arvay published his first nonfiction book on forgotten species of vegetables. The author reached a wide readership with his second book
Der große Bio-Schmäh (
The Big Organic Fraud). which was touted as being "a dispassionate and therefore also credible account." In 2013, in an additional book, Arvay advocated reining in "power-hungry food conglomerates" in favor of regional, small-scale farming. This book also was published in Japanese. In 2014, Arvay teamed up with the actor
Roland Düringer on a book titled
Leb wohl Schlaraffenland (
Farewell, Land of Plenty) in which both authors discussed the "major philosophical questions in life." As an experiment, Düringer decided to do without modern advances and to live according to the way things were 40 years ago. In the course of additional activities as an author, Arvay once again took on the ramifications of
industrial farming, in his book published in 2014, having to do above all with the artificial standardization of food by policymakers and industry, along with the practices of large seed producers. In
Der Biophilia-Effekt (
The Biophilia Effect, 2015) and
Das Biophilia-Training (
The Biophilia Training, 2016), the author analyzed the healing effect of the forest. In the two books, Arvay touted the forest as the "best fitness gym in the world"; The English edition of The Biophilia Effect was published in 2018. It contains a foreword by biologist
Marc Bekoff. In 2016, Arvay revisited this topic in a book entitled
Der Heilungscode der Natur (
The Healing Code of Nature, 2018). Specifically, the work discusses the positive effects of plants and animals on the
human immune system. His work
Biophilia in der Stadt (
Biophilia in the City, 2018) deals with the effects of nature and green spaces on urban
public health. Brain scientist
Gerald Hüther wrote the foreword to the book. In the book
Mit den Bäumen wachsen wir in den Himmel: Autistische Kinder mit der Heilkraft des Waldes fördern (
Forest therapy and the autism spectrum: advancing the development of children through biodiversity, 2019), Arvay describes developmental opportunities in the forest for children on the
autism spectrum, supporting his explanations with current research. In 2019, the
International Handbook of Forest Therapy was published by
Cambridge Scholars Publishing; it consists of two chapters that are written by Arvay. In 2020 he published
Wir können es besser (
We Can Do Better), claiming a correlation between environmental damages, loss of
biodiversity, and the emergence and spread of
SARS-CoV-2. Arvay's book
Die Naturgeschichte des Immunsystems (
The Natural History of the Immune System) was published in 2022 by Quadriga,
Bastei Lübbe. It deals with the
evolutionary development of the
immune systems of
humans,
animals, and
plants. == COVID-19 controversy ==