Why Does High Fibre Content Require High Water Intake?

There are two types of fibers like insoluble fibers and soluble fibers. Both type of fibers are necessary. A high fiber diet needs  high water intake to prevent or ease the constipation. Muscles of digestive tract push the food forward to pass out, since fibers are indigestible, they add bulk to wastes. Fluids make the food soft and make it easy for waste to leave the body. Lack of fluid intake after fiber intake will cause constipation.