Fiber can help slow digestion, especially the rate of carbohydrate digestion, according to the University of Massachusetts Medical School. Although lettuce has a reputation as a high-fiber food, its actual fiber content per serving is low, unless you eat an entire head of lettuce. That doesn't mean it doesn't have dietary and digestive value, especially if you choose the dark green varieties.
Types of Fiber
Fiber is the part of a plant that passes through the intestinal tract undigested. Although it supplies no nutritional value, fiber does have other benefits. Soluble fiber forms a gel that slows food movement through the intestines. Insoluble fiber, on the other hand, absorbs water, which softens the stool and increases its bulk. Insoluble fiber actually speeds the passage of stool through the intestines. Lettuce contains soluble and insoluble fiber.
Amounts
Although lettuce contains soluble and insoluble fiber, the total fiber count in lettuce is low. A single cup of lettuce contains around 1.3 g of total fiber. The average American consumes 14 g of fiber day and probably needs around 35 g, the Colorado University Extension reports.
Benefits
Lettuce has very little nutrition because it has few calories, although it does contain essential vitamins and minerals. Dark green lettuces have more nutritional value than iceberg lettuce, the most commonly consumed lettuce in the United States, according to the University of Illinois Extension. Because lettuce does contain fiber in small amounts, adding lettuce to your meal can help slow digestion of the entire meal, Stanford University professor Clyde Wilson explains on his website. Fiber also helps you feel fuller for longer, which can help you eat less if you're trying to lose weight.
Considerations
A high-fiber food contains 5 g of fiber or more per serving, according to the Colorado State University Extension. By that standard, lettuce does not fit into the category of a high-fiber food. Good sources of fiber contain between 2.5 and 4.9 g per serving. Although lettuce doesn't measure up as a high-fiber food, it does add some fiber; in the American diet, every gram of added fiber has benefit.
References
- University of Illinois Extension: Lettuce
- Colorado State Univeristy Extension; Dietary Fiber; J. Anderson, et al.; December 2010
- University of Massachusetts Medical School; The Healing Handbook for Persons with Diabetes; Aldo A. Rossini, M.D., et al.
- Nutrition.com: Ask the Dietitian -- Fibre
- Doctor Clyde; Surviving Fast Food; Clyde Wilson; February 2011
