Fiber Calculator
Find your recommended daily fiber intake based on your age, sex, and activity, with an adjustment for GLP-1 patients who often need more. Enter your details below.
Daily Fiber Calculator
How the fiber calculator works
This fiber calculator estimates your recommended daily fiber intake using the Institute of Medicine guidelines, which base targets on age and sex, then adjusts for activity. The general adult recommendation is about 38 grams per day for men and 25 grams for women, dropping to 30 and 21 grams after age 50. Most US adults fall far short, averaging only around 15 grams.
Why fiber matters on a GLP-1 program
Fiber is especially important if you take a GLP-1 medication like semaglutide or tirzepatide. These medications slow gastric emptying, which is part of how they reduce appetite, but that same effect can cause constipation. Adequate fiber, paired with plenty of water, is one of the most effective ways to prevent it. Fiber also moderates blood sugar and supports a healthy gut microbiome, both of which matter during weight loss. The calculator adds a few grams to your target if you indicate you are on a GLP-1 medication.
Add fiber gradually: Increasing fiber too quickly can cause bloating and gas, which is especially unwelcome on a GLP-1 medication. Raise your intake over a week or two and drink plenty of water alongside it.
Best high-fiber foods
Whole foods are the easiest way to reach your target. A few of the most fiber-dense options:
| Food | Fiber |
|---|---|
| Beans and lentils (1 cup cooked) | 15 to 16 g |
| Chia seeds (2 tbsp) | 10 g |
| Avocado (1 whole) | 10 g |
| Raspberries (1 cup) | 8 g |
| Oats (half cup dry) | 4 g |
If you find it hard to hit your target through food alone, a provider can help you build a realistic plan. For the full program, see our medical weight loss overview, and the Academy of Nutrition and Dietetics has practical tips for adding fiber.
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Fiber Is One Piece. We Handle the Whole Plan.
A free consultation with the Tactus Health team turns your fiber and nutrition targets into a plan built around your goals and your medication.
Book a Free ConsultationThis fiber calculator is an educational tool and does not constitute medical advice, diagnosis, or treatment. Fiber needs vary by individual, and targets are based on general Institute of Medicine guidelines. Increase fiber gradually and consult a licensed medical provider before making significant dietary changes, especially while taking any medication. Individual results vary.