The son of a well-known architect, Voit originally planned to be a physician and obtained his medical degree in 1854. Voit had been the pupil of two of Germany's greatest chemists, Friedrich Wöhler and Justus von Liebig. Impressed by their work, he decided to switch careers, took more courses in biochemistry and eventually became almost as widely known as his mentors because of his basic research in nutrition and metabolism. In 1863, Voit joined the faculty of the University of Munich, where he did most of his research and where he remained for the rest of his life.

When Voit began his biochemical career, a major goal was to determine, as precisely as possible, what happens to proteins, fats and carbohydrates after they are absorbed into the body. He chose this research path partly because he liked to work with clear and accurately-measured figures and partly because he...