There’s a great deal to admire and respect about vegetarianism. The idea that our bodies respond to vegetables better over the courses of our lives indicates that there is some connection between longevity and eating less meat in our diets. Take the case of John, a man born in Tyrone, Michigan, a decade before the American Civil War began. John grew up farm-raised meat products, but he was a sickly child. Self-taught for the most part, he and his family learned about what they considered to be proper nutrition from a new religious group they joined, the Seventh Day Adventists.

John became a vegetarian as a result of this religious training, and he saw an immediate improvement in his health. He slept better, he had more energy in the mornings, the constant illnesses left him. At that point, for John, there was no turning back. He worked in his father’s broom factory as a teenager before becoming a teacher at the tender age of 16. After more teacher training at what we now call Michigan State University, the members of his local Adventist Church convinced John to pursue a medical degree so he could learn more about proper nutrition that could be derived from a meatless diet. And, so, John went first to medical school at the University of Michigan and then moved east and attended New York City’s Bellevue Hospital Medical College where he received his medical degree.

Returning to Michigan, John became, essentially, a preacher of the vegetarian lifestyle. He was one of the first physicians in the US to propose that gastric distress was often caused by having the wrong biotics in the digestive tract. Many people today eat yoghurt in the United States because John’s efforts to make sure people got pro-biotics into their systems. And he opened a hospital where people with poor diets could come and learn what to eat and why. Soon, celebrities began calling at John’s place. President Taft (a man in need of diet advice if anyone was), Amelia Earhart, Roald Amundsen, and Henry Ford all came to John to receive advice on how to live better through vegetarianism.

John also was among the first to realize the protein potential of peanut butter. He collaborated with George Washington Carver down in Alabama to promote the wider use of the product along with the nutritional benefits of the sweet potato. He worked on meat substitutes, and he was among the pioneers in the development of soy and almond milks.

Now, you might wonder why you haven’t heard of John before, but, of course, you have. In fact, you mostly likely have a product of his creation in your kitchen cupboard right now. It’s probably his most famous product, and it was so popular, that it overshadowed all his other amazing medical and food-related work put together. Vegetarianism worked for John. He died at the ripe old age of 91 in 1943. And he attributed his longevity in part to the product I mentioned above.

You see, it was John Harvey Kellogg that gave us the cornflake.