According to the Formula Medical Group, the first typical symptom of insufficient dietary fiber is constipation. However, over the long term, failing to eat enough fiber may contribute to more serious health problems such as colon cancer, obesity and high cholesterol.
According to WebMD, four simple health signs can indicate a need for more dietary fiber. In addition to constipation, blood sugar fluctuations, weight gain, and nausea and tiredness may be signs of insufficient dietary fiber. Among other functions, fiber increases the feeling of satiety, or feeling full. Low-fiber foods often fail to create such satiety, which encourages overconsumption. Formula Medical states that there is no federally recommended guideline for daily fiber consumption. However, nutritionists typically recommend that adults eat between 15 and 30 grams of fiber each day. On average, Americans consume about 10 grams of fiber each day, which is insufficient for good health.
Consuming excessively high amounts of dietary fiber can also cause health problems. In addition to intestinal discomfort, gas and bloating, eating too much fiber can in rare cases cause an obstructed intestine. This is most often a concern of elderly people, who have relatively slow-moving bowels. Formula Medical Group also states that excess bran, which is high in dietary fiber, can block the absorption of zinc and other nutrients.