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Fiber is a critically important nutrient in your everyday diet. Dietary fiber promotes healthy digestion and regularity, improves gut microbiota composition, helps reduce cholesterol and improve cardiovascular health, helps control blood sugar levels and diabetes, tames appetite by keeping you fuller longer and helps regulate weight, and protects you from developing colon cancer. (1)
Sounds like an ultimate multifunction superdrug, sans the high cost and nasty side effects. A must-have in everyone’s diet.
Fiber is found in virtually all fruits, vegetables, legumes, and grains in their unprocessed, whole form, making it so ubiquitously available and affordable.
So why is it that most Americans statistically do not get enough fiber in their diet? (2)
Because the standard American diet does not offer enough fiber to satisfy the requirement range of 25-38 grams per day by the Institute of Medicine Dietary Reference Intake (DRI). (3)
Interestingly, however, most surveyed individuals are convinced they are getting enough fiber. Since most people do not engage in macro, micro, calorie, and other nutrient counting, how would they know if they are indeed eating enough fiber?!
Let’s explore some of the signs your body is trying to tell you when you lack sufficient fiber in your diet:
Fiber greatly supports regular bowel movements by bulking up stool, improving motility (promoting movement down the digestive tract), and promoting laxation and lubrication through its gel-forming properties. (4)
If you experience frequent constipation, try adding more fiber – that is, more vegetables, fruits, legumes, and grains – in your diet for improved regularity.
Although a lack of fiber in your diet does not directly cause diarrhea, it may reduce the diversity and amount of beneficial bacteria in your gut that protects you from infectious diseases and promote overall health.
See the chain reaction? Prebiotic fiber feeds good bacteria that prevent diarrhea.
3. Weight gain
Consuming sufficient amounts of fiber guarantees satiation and fullness, which reduces appetite and consumption of calorie-laden foods.
The caloric density of a food item matters when it comes to weight control. Just imagine a 200-calorie candy bar and its calorie equivalent in carrots – it takes roughly 10 medium to large carrots to get to that number.
Your candy bar will disappear within 1-5 minutes if you eat it mindfully (probably within seconds if devoured in front of a computer), whereas it will take you a long while to crunch down 10 carrots.
Plus, the high fiber content of carrots will not only fill you up (high volume), it will also slow the sugar influx into your bloodstream, keeping your blood sugar level stable along with your appetite.
A high-fiber diet is known to reduce the caloric load by preventing some calories from being absorbed in the intestines, therefore aiding weight loss. (5)
Another way dietary fiber may reduce appetite and help regulate weight is by stimulating the release of the appetite-suppressing hormone leptin through a series of complex neurochemical signaling events. (6)
Leptin is released from your fat cells in response to meals. It downregulates your appetite and stops you from overeating. (6)
Insufficient fiber intake will cause hunger pangs shortly after meals.
Not only will your smart body recognize that you are not feeding it enough of this vital nutrient, but the mechanoreceptors in your gut (those that sense stretching of your stomach and intestines) will also register low content and mount a hunger signal up to your brain.
By eating adequate amounts of fiber, you ensure satiety for longer and keep your caloric intake within reasonable need.
5. Drop in blood sugar
Hypoglycemia, or the rapid drop in blood sugar, could be caused by several different reasons. These include preexisting conditions such as type I and type II diabetes, prolonged periods of fasting, or a high-sugar low-fiber diet.
Symptoms of low blood sugar levels include extreme fatigue, shakiness, blurry vision, and cravings for sweet food. These are normally relieved by eating foods containing carbs or drinking juice or soda.
Consuming high amounts of simple carbohydrates (candy, pastries, soda) without accompanying high-fiber foods will spike your blood glucose level. Then, a sudden drop occurs as a result of the insulin response.
At this point, your body senses a dip in energy and sends you hunger signals to replenish it. This is not true hunger; however, the body is just not very good at recognizing that you have had enough calories with your high-sugar snack.
The consequences of a high-sugar diet then become a vicious cycle of “eating sugar – hypoglycemia – need for more sugar to stabilize.”
By including more fiber in your diet, you will train your body to avoid sudden blood glucose drops and only heed the true need for energy.
To ensure sufficient fiber in your diet, try to include fiber-rich foods at every meal. Have fresh fruits and berries along with whole grains such as oats as part of your breakfast.
Opt for a green salad, baked starchy veggies such as sweet potatoes, beans, and lentils with your lunch. Chilis and stews with lots of veggies served over brown rice, quinoa, or whole-grain pasta are great for dinner.
For snacks, nuts, seeds, or fruits with nut butter are some high-fiber options to try.
Expert Answers (Q&A)
Answered by Olivia DiPio, LD (Registered Dietitian Nutritionist)
Overall, darker vegetables tend to have more fiber but there are exceptions to the rule. Most of the time, the higher the intensity of the color, the more nutrients the food item contains.
Rich-colored vegetables such as beets, carrots, and broccoli have a lot of fiber. An example of the exception is artichokes, which are more of a light brown. One medium-size artichoke contains around 10 g of fiber.
If you are feeling sluggish and bloated, it is most likely due to the fact that your digestive tract is not at its healthiest. Some things you can do to increase the amount of healthy bacteria in your gut and “clear it out” would be to increase your intake of fiber, water, and probiotics.
The daily recommended intake of fiber is 25 g/day for women and 38 g/day for men. Fruits and vegetables are good sources of fiber and water content.
The skins of fruits and vegetables are where most of the fiber is from. For example, one apple contains 4 g of fiber. If you work out or have a laborious job, increase your usual water intake by 2 cups.
Lastly, probiotics keep your gut filled with good bacteria that support its function. Popular food sources of probiotics include yogurt, kombucha, sauerkraut, and miso.
Do not use supplements, pills, or teas that claim they will “clear you out” or “give you a flatter stomach.” These are quick fixes that will not improve your gut health and can put you at risk for other medical issues.
The best way to increase fiber intake is to make sure that every meal has at least two different vegetables on your plate and to make sure half of your plate is fruits or vegetables. These portions will ensure that you are getting a variety of nutrients and both types of fiber.
Oats are a great high-fiber breakfast option. It is a myth that steel-cut oats are better than rolled oats or quick oats. They all carry a similar nutrient profile, including their fiber content.
Rolled oats and quick oats have about 5 g of fiber, whereas steel-cut oats have around 6 g of fiber.
Consuming apples and berries are a great way to add fiber to your morning meals. They can be easily added to yogurt and oats for a quick breakfast.
Nuts and seeds also provide a good amount of fiber in your diet. They can be added to smoothies, yogurt, oatmeal, and a variety of recipes.
Yes, there is no bad time to eat fiber. You may consume fiber anytime or any way!
The word “side effects” to describe a nutrient is a bad connotation, the best word would be “symptom.” The negative symptoms associated with consuming fiber are bloating and gas. These symptoms most commonly occur when individuals make an extreme lifestyle change for the better or have an extremely high fiber meal.
For example, if someone followed a highly processed diet and then started eating loads of fruits and vegetables, their discomfort may be extreme.
But overall, fiber is great for your gut! It will help the transit time of food and keep you feeling full longer. As a result, you feel healthy and stay at a healthy weight.
Insoluble fiber helps add bulk to the stool and facilitates fast elimination through the intestines. Some examples of foods with a good amount of insoluble fiber are whole grains, nuts, seeds, fruit with skin, and certain vegetables.
• Have two different vegetables or fruits at each meal.
• Try to have those vegetables that are of two different colors.
• Choose whole grains over refined grains.
• Snack on seeds and nuts, but remember portion control.
• Juice does not have fiber, so have whole fruits and vegetables instead.
• Rinse and eat apples, cucumber, and potatoes with their skin on.
• Eat your legumes – beans, lentils, and chickpeas.
About Olivia DiPio, RDN: Olivia is a wellness dietitian in the Cleveland area. She is a certified dietitian who wants to help individuals create the best version of themselves. She currently works for Eurest, helping large companies establish a wellness environment.