Eating whole foods and plant-based meals can reduce your constipation risk by up to 20 percent, according to recent research, but most Americans are still consuming ultra-processed foods that actively work against digestive health. While fiber gets all the attention in clean eating conversations, gastroenterologists now emphasize that your entire dietary pattern matters far more than any single nutrient. The good news: small, strategic swaps can make a measurable difference in how your body functions.

What Does the Latest Research Say About Clean Eating and Digestive Health?

A 2025 study published in the journal Gastroenterology found that adults who ate more plant-based foods were up to 20 percent less likely to develop constipation over time . The research suggests that the benefits go far beyond simple fiber intake.

"In our study, adults who ate more plant-based foods were up to 20 percent less likely to develop constipation over time. These foods aren't just sources of fiber, they provide water, healthy fats, and antioxidant polyphenols, compounds that may support the gut microbiome and overall motility," said Kyle D. Staller, MD.

Kyle D. Staller, MD, Director of the Gastrointestinal Motility Laboratory at Massachusetts General Hospital in Boston

The problem is clear: ultra-processed foods now make up over half of the total calories that U.S. adults over age 60 consume daily . A 2024 study in the journal Clinical Gastroenterology and Hepatology found that every 10 percent increase in daily calories from ultra-processed foods raised the odds of constipation by 17 percent . These foods are notorious for containing incredibly low amounts of fiber while being loaded with sugar, salt, and unhealthy fats that actively slow digestion.

Dr. Trisha Pasricha, a gastroenterologist at Beth Israel Deaconess Medical Center in Boston, emphasizes that the solution requires looking at the bigger picture.

"We need to focus more on our overall eating pattern. That means more vegetables, fruits, nuts, and healthy fats, and less reliance on ultra-processed foods," explained Dr. Trisha Pasricha.

Dr. Trisha Pasricha, MD, Gastroenterologist at Beth Israel Deaconess Medical Center in Boston

How to Build a Clean Eating Plan That Supports Digestive Health

• Increase Fiber Gradually: Men over 50 should aim for 30 grams of fiber daily; women, 21 grams. The average American gets only 16 grams. Both soluble fiber (found in oatmeal, barley, beans, and apples) and insoluble fiber (found in wheat bran, seeds, nuts, and leafy greens) help with constipation in different ways, but most high-fiber foods contain both types .
• Prioritize Whole Plant Foods: Fruits, vegetables, whole grains, beans, nuts, and seeds act as natural laxatives and feed beneficial bacteria in your gut that support regular digestion .
• Stay Hydrated from Multiple Sources: A 2025 study in BMC Public Health found that people who got the most fluids from a variety of sources, including water, other beverages, and high-moisture foods like soup, smoothies, fruits, and vegetables, had 46 percent lower odds of experiencing constipation than those who got the least .
• Eliminate Ultra-Processed Foods: These packaged foods with many additives contain excessive levels of unhealthy fats and high amounts of sugar and salt, which can decrease water in stool and slow digestion .

Practical Swaps to Boost Fiber Without Overhauling Your Diet

Making dramatic dietary changes all at once can feel overwhelming. Instead, experts recommend small, targeted additions that add fiber and whole foods to your existing meals. These simple tweaks can help you move toward a cleaner eating pattern without the stress of a complete overhaul.

• Fiber-Rich Fruits: Raspberries contain 8 grams of fiber per cup, about twice the amount in strawberries or blueberries. A medium pear offers nearly 6 grams of fiber, mostly insoluble, compared to 4 grams in a medium apple. Recent guidelines from the British Dietetic Association suggest that kiwifruit, two to three per day, may help increase stool frequency .
• Hidden Fiber in Smoothies: White beans have a neutral flavor; when you mix one-quarter cup into a smoothie, you won't taste them but will add 3 grams of fiber and a thicker texture .
• Seeds and Nuts: Make overnight oats with 1 tablespoon of ground flax (2.4 grams of fiber) or chia seeds (4.2 grams). Scatter one-quarter cup of shelled pumpkin seeds (2 grams) over roasted squash or other vegetables .
• Overlooked Vegetables: Frozen green peas contain the antioxidants beta carotene and lutein/zeaxanthin, and one-half cup provides nearly 4 grams of fiber .
• Fiber in Desserts: Replace the oil in brownie mix with one-half cup pureed black beans and add one-half cup walnuts. For crunchy snacks, combine walnuts, wheat squares cereal, and raisins for a nutritious trail mix .

If you struggle to meet your daily fiber goal through food alone, fiber supplements can help. Psyllium husk, a soluble fiber that forms a gel in water, is the best studied supplement on the market and has the added benefit of helping to lower cholesterol levels . However, it's best to start with half a dose, mixing it into 8 ounces of water or a smoothie, and drink it immediately before it turns into a gel.

Beyond Diet: Other Factors That Support Digestive Health

Clean eating is foundational, but digestive health involves multiple lifestyle factors. A recent study in the American Journal of Gastroenterology found that 20 to 30 minutes of exercise at least five times a week may reduce the likelihood of constipation . Additionally, certain medications like some antidepressants and blood pressure medications are linked to constipation, so it's worth asking your doctor whether your prescriptions could be affecting your digestive system .

The beverage you drink also matters. Coffee can stimulate contractions in the colon and has other mechanisms that help trigger bowel movements . Small lifestyle adjustments, combined with a shift toward whole foods and away from ultra-processed options, create the conditions for better digestive health overall.

The takeaway is straightforward: clean eating isn't just about what you add to your diet; it's equally about what you remove. By reducing ultra-processed foods and focusing on whole plant foods, adequate hydration, and regular movement, you're supporting not just digestive health but your entire body's ability to function optimally.