 How long it takes food to get from one end to the other depends on gender and eating style. If you're a vegetarian male, it should just be a day or two. Though if you eat meat, it could end up being five days. Female vegetarians also mostly one or two days, but those who eat meat are most likely looking at four days. If it's just 24, 36 hours, your daily stool weight, which is what's flushing out all that excess estrogen and cholesterol, is probably going to hit that half-pound target, though if it's a couple days, you'll likely never make it. Now if you have a really good bathroom scale, you can measure stool weight directly to see if you hit that half-pound minimum, and by, of course, weighing yourself before and after.