Final answer:
The health food movement in the US gained a real following after the establishment of the World Health Organization in 1948.
Step-by-step explanation:
The health food movement in the US has deep roots. Nonetheless, it wasn't until the establishment of the World Health Organization (WHO) in 1948 that the movement gained any real following. The WHO's research on health and lifestyle brought a greater awareness of the link between diet and health, leading to the proliferation of healthy diets like the Mediterranean diet and the paleo diet.