Russell Trall, M.D., lays out the physiological and medical arguments for a vegetarian diet- in 1860!
Key Points:
Trall claims that the human body is best suited to a simple, plant-based diet and that rich, animal-heavy foods overload digestion and blood.
He links common 19th‑century diseases to stimulants (alcohol, coffee, tobacco) and heavy flesh eating, arguing these habits blunt both body and mind.
The book tries to move vegetarianism from a moral preference to a scientific stance, using anatomy and physiology to argue that dietary reform is public health reform.