The Two Numbers: Adequate Intake and Suggested Dietary Target
NHMRC publishes two separate benchmarks for dietary fibre, and they're easy to mix up. The Adequate Intake (AI) is set at the median fibre intake recorded in national nutrition surveys, the amount associated with normal gastrointestinal function. The Suggested Dietary Target (SDT) is a second, higher benchmark, set with long-term health in mind rather than deficiency prevention. Both are published by NHMRC in the Nutrient Reference Values for Australia and New Zealand.
Adults, by Sex
For adults aged 19 and over, the Adequate Intake is 30g a day for men and 25g a day for women, the same across every adult age band NHMRC publishes (19–30, 31–50, 51–70, and 70-plus). The Suggested Dietary Target is 38g a day for men and 28g a day for women.
Children and Teenagers, by Age Band
NHMRC's Adequate Intake for children and teenagers rises through each age band:
| Age | Adequate Intake |
|---|---|
| 1–3 years | 14g/day |
| 4–8 years | 18g/day |
| Girls 9–13 years | 20g/day |
| Boys 9–13 years | 24g/day |
| Girls 14–18 years | 22g/day |
| Boys 14–18 years | 28g/day |
No Adequate Intake is set for infants under 12 months; NHMRC notes there are no functional criteria for dietary fibre at that age, and human milk contains none.
Pregnancy and Breastfeeding
| Life stage | Age | Adequate Intake |
|---|---|---|
| Pregnancy | 14–18 years | 25g/day |
| Pregnancy | 19–50 years | 28g/day |
| Breastfeeding | 14–18 years | 27g/day |
| Breastfeeding | 19–50 years | 30g/day |
NHMRC's rationale is straightforward: the increase tracks the higher energy needs of pregnancy and lactation, rather than any separate fibre requirement specific to those life stages.
How Australians Compare
A peer-reviewed analysis of the 2011-12 National Nutrition and Physical Activity Survey found Australian adults had a median fibre intake of 20.7g a day, with only 28.2% meeting the Adequate Intake and 17.0% meeting the Suggested Dietary Target. It remains the most recent published breakdown with this level of demographic detail; ABS's 2023 "Food and nutrients" release reports fibre only as a share of energy intake, not in grams against these benchmarks.
How to Count Your Own Intake
The most direct way is to add up the "Dietary Fibre" line from the nutrition information panel on everything you eat across a day or two, a rough but genuinely useful check against these targets. Fresh fruit, vegetables and legumes rarely carry a panel but contribute meaningfully, so a food composition database or app that includes whole foods will give a more complete picture than packaged items alone.
Sources
- NHMRC, Nutrient Reference Values for Australia and New Zealand: Dietary Fibre
- Fayet-Moore F, et al., "Dietary Fibre Intake in Australia. Paper I," Nutrients, 2018, PMC
- ABS, Food and Nutrients, 2023