Macronutrient Requirements by Age & Sex

Protein, carbohydrate, fat, fibre, and water targets for every life stage — based on Australian NHMRC and US NASEM reference values.

What are macronutrients? They’re the nutrients your body needs in large quantities: protein, carbohydrates, and fat — plus fibre and water. Unlike micronutrients (vitamins and minerals), they’re measured in grams rather than micrograms.

Acceptable Macronutrient Distribution Ranges (AMDR)

These are the recommended ranges for each macronutrient as a percentage of total daily energy. Staying within these ranges is associated with adequate micronutrient intake and reduced chronic disease risk.

Age Group	Protein	Carbohydrate	Fat
Children 1–3	5–20%	45–65%	30–40%
Children 4–18	10–30%	45–65%	25–35%
Adults 19+	10–35%	45–65%	20–35%
Pregnancy / Lactation	10–35%	45–65%	20–35%

Daily Energy Requirements

Values below are in kilocalories (kcal) based on activity level. “Sedentary” means less than 30 min light activity per day. “Moderate” is 30–60 min daily. “Active” is 60+ min daily.

Age/Sex Group	Sedentary	Moderate	Active
Children 2–3	1,000	1,000–1,400	1,000–1,400
Girls 4–8	1,200	1,400–1,600	1,400–1,800
Boys 4–8	1,400	1,400–1,600	1,600–2,000
Girls 9–13	1,600	1,600–2,000	1,800–2,200
Boys 9–13	1,800	1,800–2,200	2,000–2,600
Females 14–18	1,800	2,000	2,400
Males 14–18	2,200	2,400–2,800	2,800–3,200
Females 19–30	2,000	2,000–2,200	2,400
Males 19–30	2,400	2,600–2,800	3,000
Females 31–50	1,800	2,000	2,200
Males 31–50	2,200	2,400–2,600	2,800–3,000
Females 51–70	1,600	1,800	2,000–2,200
Males 51–70	2,000	2,200–2,400	2,400–2,800
Females 71+	1,600	1,800	2,000
Males 71+	2,000	2,200	2,400
Pregnant (2nd tri)	+340 kcal/day above baseline
Pregnant (3rd tri)	+452 kcal/day above baseline
Lactating (0–6 mo)	+330 kcal/day above baseline
Lactating (6–12 mo)	+400 kcal/day above baseline

Protein RDA (grams per day)

Age/Sex Group	RDA (g/day)	Per kg body weight
Children 1–3	13 g	1.05 g/kg
Children 4–8	19 g	0.95 g/kg
Girls 9–13	34 g	0.87 g/kg
Boys 9–13	34 g	0.87 g/kg
Females 14–18	46 g	0.77 g/kg
Males 14–18	52 g	0.77 g/kg
Females 19–70+	46 g	0.75 g/kg
Males 19–70+	64 g	0.84 g/kg
Pregnant	60 g	+10 g above baseline
Lactating	67 g	+16 g above baseline

Older adults: Many experts recommend 1.0–1.2 g/kg/day for adults over 65 to prevent sarcopenia (age-related muscle loss) — significantly higher than the standard RDA of 0.75–0.84 g/kg.

Understanding Net Protein — food weight vs actual protein

When a food is listed as containing protein, that’s the protein content by weight — not the weight of the food itself. This is one of the most common sources of confusion when meal planning.

Example: 150g of raw chicken breast contains approximately 33g of protein (about 22% by weight after cooking). Not 150g of protein.

Common foods — protein per 100g (cooked / as eaten)

Food	Protein per 100g
Chicken breast	~31g
Beef mince (lean)	~26g
Canned tuna	~25g
Canned sardines	~22g
Cheddar cheese	~25g
Eggs (whole)	~13g
Greek yoghurt	~10g
Oats (dry)	~17g
Firm tofu	~8g
Cooked lentils	~9g
Cooked chickpeas	~8.9g
Cow’s milk	~3.4g

Bioavailability: Animal proteins are 90–99% digestible. Plant proteins are typically 50–80% digestible, and most are low in at least one essential amino acid — so vegans and vegetarians need roughly 10–20% more total protein to absorb the same amount.

Leucine threshold: Muscle protein synthesis requires approximately 2.5–3g of leucine per meal. Three meals of 30g protein stimulates muscle growth more effectively than one meal of 90g. Distribution across the day matters — especially for older adults.

Fibre (Adequate Intake)

Most Australians get approximately 20g/day — well below target for most demographics. Fibre is the most commonly underconsumed macronutrient.

Age/Sex Group	AI (g/day)
Children 1–3	14 g
Children 4–8	18 g
Girls 9–13	20 g
Boys 9–13	24 g
Females 14–18	22 g
Males 14–18	28 g
Females 19–50	25 g
Males 19–50	30 g
Females 51+	22 g
Males 51+	25 g
Pregnant	25–28 g

Best budget fibre sources: Lentils (8g/100g cooked), oats (10g/100g dry), canned beans (6–8g/100g), brown rice (1.8g/100g cooked), potatoes with skin (2.2g/100g). A bowl of oats + a tin of lentils in a meal = roughly 18–22g fibre alone.

Water (Adequate Intake)

Age/Sex Group	AI (L/day — all sources)
Children 1–3	1.3 L
Children 4–8	1.7 L
Girls 9–13	2.1 L
Boys 9–13	2.4 L
Females 14–18	2.3 L
Males 14–18	3.3 L
Females 19+	2.7 L
Males 19+	3.7 L
Pregnant	3.0 L
Lactating	3.8 L

All sources count: The daily target includes all fluid — not just plain water. Approximately 20–30% comes from food alone. Cucumber (96% water), tomatoes (94%), oranges (87%), milk (87%), oats with milk — all contribute. A typical vegetable-rich day provides 700–900 mL from food before drinking anything. Tea and coffee count too (contrary to myth, moderate caffeine does not cause net fluid loss).

Signs you’re under-hydrated: urine darker than pale yellow, afternoon headaches, constipation, fatigue, difficulty concentrating. These often appear before thirst does.

See the full NRV Reference Tables for detailed micronutrient targets by age and sex. For foods that cover these nutrients on a budget, see the Which Foods Fill Which Gaps guide.

Sources: NHMRC Australian Nutrient Reference Values (2006, updated 2017) · Dietary Guidelines for Americans 2020–2025 (USDA/HHS) · Institute of Medicine Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005)

Macronutrient Requirements by Age & Sex

Acceptable Macronutrient Distribution Ranges (AMDR)

Daily Energy Requirements

Protein RDA (grams per day)

Understanding Net Protein — food weight vs actual protein

Common foods — protein per 100g (cooked / as eaten)

Fibre (Adequate Intake)

Water (Adequate Intake)

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