How much time does it take your body to metabolize junk food?

Metabolic rates: The time it takes to metabolize junk food is the same as for other foods - most of the variation in times for digesting foods have to do with how quickly the food can be broken down, and how quickly the food moves from your stomach through your bowels. High fiber foods tend to be broken down and absorbed more slowly. Fatty foods move through more slowly. Junk foods are often low fiber but high fat.