Does Fiber Help with Weight Loss? 15 Fiber-Rich Foods, According to a Dietitian

Fiber, alongside protein, is having a big moment in the wellness world, yet the benefits of this essential carbohydrate have been well-studied for decades. Beyond supporting weight loss and management, getting enough fiber is vital for combating rising colon cancer rates in young people. It also helps control blood sugar, a must for people with diabetes.

Teresa Pangan, UnityPoint Health dietitian, breaks down the best natural food sources of fiber, discusses if it's possible to overdo it, the impact on your gut and how fiber keeps you healthy while assisting with weight loss goals.

How Much Fiber Per Day?

The general recommendation for fiber intake in healthy adults is 25-30 grams per day.

“Most people consume well below that, so try gradually including more fiber in your diet but be careful to not add too much at once as it can cause digestive upset,” Pangan says.

Can Too Much Fiber Cause Constipation?

Too much fiber overwhelms your gut bacteria, causing gas, bloating, constipation and diarrhea.

Pangan says, “Don’t start with 40 grams a day. Gently ramp up your fiber intake over a few weeks while drinking plenty of water. This approach helps most people avoid an upset stomach, though people with conditions like irritable bowel syndrome should talk to their doctor or dietitian before increasing their fiber.”

How Does Fiber Help with Weight Loss?

Eating enough fiber can help with weight loss efforts.

“Fiber rich foods take longer to eat and digest,” Pangan says. “They stretch out your stomach and trigger fullness hormones, leading to lower caloric intake and better appetite control.”

Because you need to take in less calories to lose weight, your fiber intake is likely slightly less than the norm, too. Instead of 25-30 grams a day, aim for at least 20-25.

“The American Diabetes Association recommends 14 grams per 1,000 calories. So, 28 grams of fiber is appropriate for a 2,000-calorie diet. However, most people trying to lose weight eat less than 2,000 calories,” Pangan says.

What Foods are High in Fiber?

Try any of these fiber-rich foods that support weight loss and are stacked with nutrients:

• Apples: A source of soluble and insoluble fiber when you keep the skin on, apples contain about four grams of fiber.
• Artichoke: With tons of nutrients to complement the 10 grams per cup it offers, artichokes are a great way to get high-fiber vegetables in your diet.
• Avocados: Not only does it pack a fiber punch with 10 grams, avocados are high in healthy fats and low in carbohydrates.
• Berries: These sweet treats are an excellent high-fiber food for snacking or as a side with your breakfast. 
• Beans: A legume, beans are a food that’s high in fiber and protein.
• Broccoli: A cruciferous vegetable (a plant in the mustard family that’s full of fiber), there are about 2.5 grams of fiber in half a cup of cooked broccoli.
• Brussel sprouts: Like broccoli, Brussel sprouts are a cruciferous veggie and have ample fiber per cup, about four grams.
• Chia seeds: A great high-fiber, low-carb food that’s high in protein, an ounce has about 10 grams of fiber and five grams of protein.
• Chickpeas: With about six grams of protein per half cup and six grams of fiber, chickpeas are a great high-fiber food for weight loss.
• Flax seeds: Like chia seeds, flax seeds are low carb but high in fiber and protein. Just two tablespoons provide four grams of fiber and four grams of protein.
• Lentils: Nearly 18 grams of protein and 15 grams of fiber, lentils are a great side to work in your lunches and dinners.
• Oats: Adding oats to your breakfast rotation also adds about eight grams of fiber per dry cup.
• Pears: With the skin, a large pear has about seven grams of fiber, making it a tasty high-fiber snack.
• Quinoa: A complete protein, quinoa contains all nine essential amino acids while toting eight grams of protein and five grams of fiber per cooked cup.
• Soy nuts: One of the highest snacks in fiber and protein, you can get 37 grams of protein and 17 grams of dietary fiber from a cup of soy nuts.

What Does Fiber Do to Your Poop? Soluble vs. Insoluble Fiber

Understanding the different types of fiber helps you make better choices for your gut health and regularity.

Pangan explains, "There are two different types of fiber: soluble and insoluble. Any whole food is a combination of both, but stronger in one area. Soluble fiber is kind of like a sponge in the gut. It soaks up water, slows things down and forms a gel that traps cholesterol and sugar, so they're absorbed less quickly.”

If you have trouble with loose stools, eating more soluble fiber can help with diarrhea — firming up bowel movements and reducing their transit speed.

She adds, “Insoluble fiber is like a broom, because it sweeps through the digestive system and keeps everything moving, clearing out waste so trouble can't grow. Common sources include wheat bran, and the skin and seeds of fruits and vegetables. It adds bulk and speeds transit, which makes insoluble fiber really good at preventing constipation."

How Fiber Helps Prevent Colon Cancer

Considering the rising rates of colon cancer in young people, the role of fiber in prevention is crucial.

Pangan says, "Fiber plays several vital roles in gut health. First and foremost, it keeps things moving through our system, preventing anything from lingering where it shouldn't. It also maintains healthy stool consistency and, importantly, feeds the trillions of microorganisms in our large intestine. Fiber is essentially food for these bacteria, which comprise 70% or more of our immune system. You want to cultivate a beautiful garden in your gut by feeding these beneficial microorganisms a variety of whole grains, fruits and vegetables. These good bacteria communicate with the rest of our body and create beneficial compounds, like short-chain fatty acids, that contribute to overall health."

Talking to Your Doctor about Fiber and Weight Loss

Eating more fiber offers a cascade of health benefits, from helping with weight loss, promoting digestive regularity, supporting a robust immune system and reducing the risk of serious diseases like colon cancer.

If you're considering making major dietary changes or have underlying health conditions, talk to your doctor, or a registered dietitian, to personalize your fiber intake and ensure it aligns with your specific health needs and goals.