Fasting quick reference - healthy elective patients
These are guideline comparisons for appropriate elective patients, not a universal fasting prescription. Application depends on aspiration-risk assessment and the applicable institutional policy.
Clear liquids Common international minimum: up to 2 h before anaesthesia in healthy elective patients. ASA 2023 supports carbohydrate-containing clear liquids until 2 h. ISA 2020: clear liquids up to 2 h in adults.
Light meal / non-human milk ASA 2017: 6 h. The amount and type of intake matter. ISA 2020: light meal 6 h; it separately classifies non-clear liquids at 4 h.
Fried/fatty food or meat ASA 2017: additional fasting time, e.g. 8 h or more. ISA 2020: heavy meal - prudent to wait at least 10 h.
Children - clear liquids ASA 2023: insufficient evidence for universal 1 h vs 2 h; the guideline encourages clear liquids as close to 2 h as possible in low-risk children. ISA 2020: water up to 3 mL/kg until 1 h; other clear liquids up to 3 mL/kg until 2 h.
Newer adult consensus
The 2026 international multidisciplinary consensus supports a 2-hour clear-liquid interval unless an institution uses a more liberal policy. It permits small milk additions to tea or coffee within its stated definition, unlike a blanket no-milk rule. This adult consensus does not replace paediatric or high-risk pathways.
Sources
- ISA fasting guideline 2020
- ASA fasting guidelines 2017 and 2023
- International multidisciplinary adult fasting consensus 2026