What Is Fiber And Why Is It Important For Weight Loss?
Fiber is a type of carbohydrate also called roughage. This nutrient is available in many plant-based foods. Though fiber is a type of carbohydrate, it cannot be broken down into sugars in the body. There are two common types of dietary fibers.
Soluble fiber - This is fiber that is easily dissolved in the body. It turns into a gel-like substance in the body and leaves the person feeling full for a longer time.
Insoluble fiber - This is fiber that does not dissolve in the body. It moves through the digestive system as such and can prevent problems like constipation.
The soluble and insoluble fibers are further classified into different types depending on their sources.
Both these types of fibers keep you healthy.
In recent times, fibers have become even more important for their ability to help with weight loss.
Fiber At The Molecular Level - Getting Technical
Soluble fiber is not processed in the small intestine. In the stomach, it absorbs water and turns into a gel. This moves through the small intestine and reaches the large intestine. Here, soluble fibers are acted upon by the bacteria present in the large intestine.
This process is called fermentation. Fermentation results in certain nutrients that are beneficial to your body.
The remaining soluble fiber helps give body (volume) to your stool. The water content in the soluble fiber is also retained and passed out with your stools.
The insoluble fibers meanwhile pass through the small intestine and the large intestine unchanged. Except for a few types, the insoluble fibers are not fermented. Bigger molecules of insoluble fibers trigger the production of mucus in the large intestine. These provide volume to your stool and make passing stools easier.
Smaller molecules of insoluble fibers can be constipating.
While still not a macronutrient, dietary fiber is gaining status as a very important nutrient.
The significance of fiber
- A high-fiber diet brings down the risk of cardiovascular diseases
- Fiber can prevent gastrointestinal problems like ulcers, Irritable Bowel Syndrome (IBS), constipation, and even colon cancer
- Few studies prove a high-fiber diet brings down the risk of breast cancer
- Fiber flushes toxins from the body, improving your skin’s appearance
- Fibrous foods help with weight loss
The significance of fiber in weight loss
Many studies conclude that a fiber-rich diet helps with weight loss. Here are the reasons why.
- Fiber-rich food keeps you full for a longer time and brings down appetite. This can help with weight loss over time
- Fiber prevents fluctuations in blood sugar levels. When sugar levels don’t go up and down drastically, your body goes through lesser sugar cravings and hunger.
- Fiber keeps the gut healthy and clean. This regulates digestion.
Did You Know?
Even though fiber passes through the body mostly unchanged, there are few places where your body smartly breaks it down into portions that it can easily handle.
The minute you eat fiber-rich food, your teeth and jaw work to break down the food into smaller portions. This action changes the physical appearance and structure of the fiber. After it reaches the stomach, the churning action of the stomach muscles also helps in further altering its physical structure.
The fiber content is further broken into smaller parts. From here until fiber reaches the large intestine, it mostly remains the same.
Fiber keeps your gut healthy by flushing out excess LDL cholesterol and other unwanted deposits in the digestive tract as it travels down.
The Story Behind Fiber
The story of fiber goes back to the times of ancient Greece. Greeks consumed wheat bran regularly as they thought it helped prevent constipation. They did not know why wheat bran helped though.
It was only in the 19th century that people started looking more intently into fiber and its benefits. The benefits of fiber in curing constipation was introduced in America by J.H Kellogg, a doctor, who later created the iconic Kellogg cereal brand.
Kellogg initially pointed to the lack of fiber as a reason for two common conditions prevalent then - constipation and masturbation. He sincerely believed that including a lot of fiber in food will ‘treat’ these conditions.
Kellogg and his family came up with a kind of granola that was full of fiber content. In 1953, a British physician first coined the term ‘dietary fiber’.
The early 1900s saw a lot of demand for these fiber-rich breakfast options and slowly, foods with higher fiber content became popular choices in families with healthy food choices.
As nutritionists and doctors started understanding what fiber did to the body, the link between high fiber and weight loss became a well-researched topic.
Total dietary fiber intake should be 25 to 30 grams a day from food, not supplements.
Did you know that the average American gets only about 15 grams of fiber a day?
How Genetics Influence Fiber Related Weight Loss
FTO gene
The FTO gene is associated with obesity, type II diabetes, and body-mass index. A particular variant of the FTO gene seems to have a relationship between lower waist circumference and a high-fiber diet.
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A allele - Individuals are likely to lose more weight upon fiber intake. Their waist circumference also reduces.
T allele - Individuals are likely to lose moderate to less weight upon fiber intake with a lesser reduction in waist circumference.
TCF7L2 gene
The TCF7L2 gene produces the TCF7L2 protein. A variation in this gene plays an important role in increasing/decreasing the risk of type II diabetes in relation to fiber intake. Type II diabetes and sharp sugar highs and dips in the body are directly related to weight gain.
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There are three genotypes of this SNP that relate fiber intake to risk of diabetes and weight loss. Individuals with the CC and CT genotype have lesser risk of developing type II diabetes upon fiber intake.
These individuals also lose more weight when they include fiber-rich foods. Those with the TT genotype are not protected against diabetes type II because of a high fiber diet and also lose only moderate to less weight upon fiber intake.
Non Genetic Factors That Relate Fiber And Body Weight
Feeling of fullness - Fiber-rich food is often bulky and fills you up well. It takes a long time for fiber to pass through the digestive tract too. Because of these reasons, fiber gives you a sense of being full for a longer time. This prevents re-snacking in between meals and can help with weight loss.
Low calories - Many fiber-rich foods are low in calories. Their energy density is lesser than foods rich in simpler carbohydrates. This means that even if you eat your normal quantity, you are getting lesser kilojoules/gram of the food. Choosing a fiber-rich meal is hence a perfect way to bring down the caloric intake and lose weight.
Lowered risk of sugar dips - When you have a normal carbohydrate-rich meal, carbs are quickly broken down into sugars and are absorbed right away. This causes a sharp increase in blood sugar levels and once the sugars are absorbed, a sharp dip too. Sugar dip can make you crave food again, especially sugary snacks and desserts. Fiber prevents the sharp sugar dips from happening and maintains your sugar levels stable. You will hence snack less and lose weight faster.
What are the symptoms of fiber overdose?
While many people are only fiber deficient, it is possible to get an overdose of fiber when you do not plan your diet right.
When you consume more than 70 grams of fiber a day, these could be some of the side effects noted.
- Bloating and flatulence (passing of wind)
- Abdominal pain and cramps
- Diarrhea or constipation (depending on the type of fiber you over-consume)
- Weight gain
- Low blood sugar levels
- Nausea and vomiting
- Dehydration
- Excessive weight loss
What are the symptoms of fiber deficiency?
When you consistently get lesser fiber than what’s recommended, here are some of the symptoms to look out for:
- Constipation
- Irritable Bowel Syndrome (IBS)
- Diverticulitis (hernia in the digestive tract)
- Hemorrhoids (swollen veins in the rectum)
- Increased risks of colon cancer
- Weight gain
Recommendations For Healthy Weight Loss With A Fiber-based Diet
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Switch over from simple carbohydrates to wholemeal or multi grains. Replacing your loaf of white bread with wheat bread or your regular pasta with a multigrain pasta will automatically increase your fiber intake.
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Choose a healthy cereal-based breakfast. Make it a point to eat a bowl of barley, oats, wheat, or a mixed cereal meal the first thing in the morning to give you a fiber-kick.
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Make sure you include at least 2-3 portions of fruits and vegetables a day. Try eating them with their skin to improve their fiber value.
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Snack on nuts and seeds. These are tastier and also fiber-rich.
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Plan your meals right. Consciously make sure you pick fresher produce to cook with. Fibrous fruits and vegetables along with a couple of portions of grains, lentils, and legumes will satisfy your body’s fiber needs easily. With the right fiber intake and moderate physical activity, you will lose weight consistently.
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Get your genetic testing done. If your genes don’t help you lose weight upon fiber intake, you might have to take extra efforts in working out and restricting calories to bring down body weight.
Summary
- Fiber, also called roughage, is quickly gaining popularity as an important nutrient needed for the healthy functioning of the body.
- This is a type of carbohydrate that is available in foods in soluble and insoluble forms. 3. A high fiber diet is associated with an increased chance of weight loss.
- High-fiber diet prevents constipation, cardiovascular diseases, risks of type II diabetes, and keeps the gut healthy.
- Some people are genetically designed to lose more weight with increased fiber intake than others.
- Making sure you get your daily recommended dose of fiber will help you stay fit and healthy.
Reference
https://www.forbes.com/sites/priceonomics/2016/05/17/the-surprising-reason-why-dr-john-harvey-kellogg-invented-corn-flakes/?sh=45da5e766997
https://www.theguardian.com/business/2006/dec/28/food.usnews
https://www.otsuka.co.jp/en/health-and-illness/fiber/about/history/
https://www.healthline.com/health/food-nutrition/how-much-fiber-per-day
https://medlineplus.gov/ency/article/002136.htm
https://www.ucsfhealth.org/education/increasing-fiber-intake
https://www.medicalnewstoday.com/articles/321286#symptoms
https://www.betterhealth.vic.gov.au/health/healthyliving/fibre-in-food
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3433658/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4807705/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3478519/
