We all have our own eating routines—whether it’s chowing down on a bowl of Honey Nut Cheerios every morning for breakfast, or hitting up the same deli a block away from your office every Friday for lunch.

These are ordinary eating routines, ones that give us order and structure that we can rely on in our hectic lives. But then there those people in the world with insane, ridiculous, and questionable eating routines. Have you heard of the man who has eaten nothing but raw animal flesh for the past five years? What about the girl who ate only at Starbucks for all of 2013? Or maybe you’ve read about the 78-year-old man that has eaten the same halibut dish at the same restaurant for more than two decades?

The results of these extreme diets vary. Some folks come out on top, as is the case with the man who ate at McDonald’s for 90 days and dropped tons of weight, as well as the now-famous Jared, who lost more than 200 pounds from eating at Subway for a year. But there are definitely downsides to eating at one spot for a prolonged period of time: Just look at what happened to Morgan Spurlock during his month-long McDonald’s binge.

The nine folks profiled in this story are fascinating and strange, but we applaud them for turning themselves into human guinea pigs so that the rest of us might learn from their experiences.

Meet nine people who have submitted themselves to extreme diets, and find out what happened to them.