Kellogg's accidental creation of corn flakes had a profound impact on the food industry, leading to the development of the ready-to-eat cereal market. The Kellogg Company continues to be a major player in the global food industry.

Kellogg's emphasis on vegetarianism, whole grains, and exercise has continued to influence health and wellness movements. Many of his ideas are now considered mainstream, although some of his more extreme views remain controversial.

Kellogg's legacy remains complex and contested due to his controversial views on sexuality and eugenics. While he is recognized for his contributions to health reform and the development of the cereal industry, he is also criticized for his harmful beliefs and practices.

Historians continue to re-evaluate Kellogg's life and work, seeking to understand the complexities of his character and the context of his time. He is often viewed as a contradictory figure, a progressive reformer with some problematic beliefs.