Fiber: how much is recommended per day and what this figure is based on

Fiber is part of plant-based foods, for which different institutions establish population-level intake guidelines. These are not personal prescriptions: individual needs may depend on diet, the energy content of the diet, and other individual circumstances.

What the evidence says

The European Food Safety Authority (EFSA) defines adequate dietary fiber intake for adults in the European Union as 25 g per day. The term “adequate intake” means a population-level guideline, not a mandatory individual target for every person.

The UK National Health Service (NHS) sets a target of at least 30 g of dietary fiber per day for adults. The NHS also notes that average actual intake in the United Kingdom is around 20 g per day. Therefore, the figure of 30 g is a guideline for increasing fiber intake across the population, not a statement that every person must reach it in the same way.

The Australian National Health and Medical Research Council (NHMRC) and the New Zealand Ministry of Health provide different guidelines for men and women: adequate fiber intake is 30 g per day for men and 25 g per day for women. In the United States, the U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (HHS) use a different approach—at least 14 g per 1000 kcal of the diet. For a 2000 kcal diet, this corresponds to 28 g per day.

What this looks like in practice

These recommendations can be read as a range of population-level guidelines rather than one universal figure. For adults, the guidelines cited include 25 g, 28 g, or 30 g per day, while the American approach additionally links the target to the energy content of the diet.

• EFSA gives 25 g of fiber per day as adequate intake for adults in the EU.
• The NHS recommends at least 30 g per day for adults.
• Australia’s NHMRC and the New Zealand Ministry of Health give 25 g per day for women and 30 g per day for men.
• The USDA and HHS in the United States use a guideline of at least 14 g per 1000 kcal of the diet.
• For a 2000 kcal diet, the American formula gives 28 g of fiber per day.

In practice, fiber comes from a variety of plant-based foods: vegetables, fruit, legumes, whole grains, nuts, and seeds. This approach helps shift the focus away from exact counting and toward regularly including different sources of fiber in the diet.

What to keep in mind

The difference between 25 and 30 g per day does not mean that one recommendation is right and the others are wrong. Institutions use different assessment systems: EFSA gives adequate intake for adults in the EU, the NHS sets a target for adults in the United Kingdom, Australian and New Zealand guidelines distinguish between recommendations for men and women, and the United States links the calculation to the energy content of the diet.

All these figures are population-level guidelines, not personal prescriptions. If you change the amount of fiber in your diet, consider your own tolerance and the overall structure of your eating pattern. If you have specific dietary needs or questions about your diet, it is appropriate to discuss them with a qualified professional.

In brief

• EFSA: 25 g of fiber per day for adults in the EU.
• NHS: at least 30 g per day for adults in the United Kingdom.
• Australia and New Zealand: 25 g per day for women and 30 g for men.
• United States: at least 14 g per 1000 kcal; at 2000 kcal, 28 g per day.
• These are population-level guidelines, not personal prescriptions.

This is general information about nutrition and habits, not medical advice. If you are pregnant, breastfeeding, taking medication, or have a chronic condition, discuss dietary changes with your doctor.