A competitive market for "healthy diets" arose in the nineteenth century developed world, as migration and industrialization and commodification of food supplies began eroding adherence to traditional ethnocultural diets, and the health consequences of pleasure-based diets were becoming apparent. As Matt Fitzgerald describes it, "This modern cult of healthy eating is made up of innumerable sub-cults that are constantly vying for superiority. ...Like consumer products in commercial markets, each of these diets has a brand name and is advertised as being better than competing brands. The recruiting programs of the healthy-diet cults consist almost entirely of efforts to convince prospective followers that their diet is the
These diets are generally restrictive, and are characterized by promises of fast weight loss or great physical health, and which are not grounded in sound science.
These diets are often endorsed by celebrities or medical professionals who style themselves as "gurus" and profit from sales of branded products, books, and public speaking.
These diets attract people who want to lose weight quickly and easily and keep that weight off or who want to be healthy and find that belonging to a group of people defined by a strict way of eating helps them to avoid the many bad food choices available in the developed world.
98% of people who diet using these diets in order to lose weight gain it back within 5 years; fad diets fail because many of them are not sustainable, and people revert to former eating habits when the diet fails.
Healthy eating is simple, according to Marion Nestle, who expresses the mainstream view of healthy eating:
David L. Katz, who reviewed the most prevalent popular diets in 2014, noted: