The most common cause of constipation is a diet low in fiber found in vegetables, fruits, and whole grains
and high in fats found in cheese, eggs, and meats. People who eat plenty of high-fiber foods are less likely
to become constipated.
Fiber--soluble and insoluble--is the part of fruits, vegetables, and grains that the body cannot digest.
Soluble fiber dissolves easily in water and takes on a soft, gel-like texture in the intestines. Insoluble
fiber passes almost unchanged through the intestines. The bulk and soft texture of fiber help prevent hard,
dry stools that are difficult to pass.
On average, Americans eat about 5 to 20 grams of fiber daily, short of the 20 to 35 grams recommended
by the American Dietetic Association. Both children and adults eat too many refined and processed foods
in which the natural fiber is removed.
A low-fiber diet also plays a key role in constipation among older adults. They often lack interest in
eating and may choose fast foods low in fiber.
In addition, loss of teeth may force older people to eat soft foods that are processed and low in fiber.