1. Memori
  2. ›
  3. Articles

What Young Children Should Drink — The Evidence on Juice, Milk, Tea, and Caffeine

By Leon MoriguchiPublished May 15, 2026Updated May 18, 20266 min read日本語版あり
Audience
Parents of children aged 6 months to 6 years

TL;DR

  • ·100% fruit juice has firm limits: none at all before age one, and the AAP caps it at 4 oz/day for ages 1–3 because juice displaces nutrition and shares the same dental-caries risk as sweetened drinks
  • ·The more cow's milk toddlers drink, the lower their iron stores tend to be (a U.S. consensus statement suggests 16–24 oz, about 480–720 ml, a day at 12–24 months and up to 16 oz, about 480 ml, at ages 2–3), because milk crowds out iron-rich foods; green tea with meals cuts non-heme iron absorption and is better saved for a while after eating
  • ·Barley tea and water are the default safe beverages for young children — their physiologically neutral profile is not cultural accident but reflects genuine nutritional reasoning

Contents

  1. Lead
  2. Juice — The AAP's 2017 Recommendations and Their Basis
  3. Milk — Timing of Introduction and the Problem of Excess
  4. Tea — The Difference Between Barley Tea and Green Tea
  5. Caffeine — How to Think About the Upper Limit
  6. Practical Takeaways
  7. Summary
  8. References

Lead

"It's 100% fruit juice, so it should be fine." "Milk has calcium — I want them to drink plenty." "Isn't green tea healthy, even for kids?" When it comes to drinks, well-intentioned assumptions can quietly distort a child's nutritional balance.

This article works through the main beverages relevant to infancy and early childhood — juice, milk, tea, and caffeine — using numbers from clinical guidelines and key studies.

Juice — The AAP's 2017 Recommendations and Their Basis

The American Academy of Pediatrics (AAP) revised its guidance on fruit juice in 2017 [1]. Three key points:

  • Under 1 year: no juice of any kind, without exception
  • Ages 1–3: no more than 4 oz (approximately 120 ml) per day
  • Ages 4–6: no more than 6 oz (approximately 180 ml) per day

Crucially, these limits apply to 100% fruit juice — not just sweetened fruit drinks.

The AAP based these restrictions on two main concerns. First, dental caries: tooth decay caused by bacterial acids dissolving enamel; sugars and organic acids from juice accelerate this process: the sugars in juice combine with organic acids to erode tooth enamel in the same way fruit solids do. Second, nutritional displacement: juice contains no fiber and provides no chewing stimulus; the same calories from whole fruit produce greater satiety. Excessive juice consumption in early childhood has been associated with short stature and obesity [2].

The belief that 100% juice is categorically safe is not consistent with current guidelines. Sports drinks, carbonated beverages, and fruit-flavored drinks (juice content below 100%) are, for practical purposes, unnecessary in children aged 1–3.

Milk — Timing of Introduction and the Problem of Excess

Cow's milk should not be given as a primary beverage before 12 months. On this point the AAP [3], the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) [4], and Japan's Ministry of Health, Labour and Welfare [5] agree. Two reasons: renal load: the burden that protein and mineral content places on kidneys; cow's milk mineral concentration exceeds infant kidney capacity (the protein and mineral concentration in cow's milk exceeds the capacity of an infant's kidneys) and the risk of iron-deficiency anemia [3][5].

Cow's milk is very low in iron, and in infants it has also been reported to cause small, invisible amounts of blood loss from the intestine [3]. Breast milk or infant formula is the standard for this age group.

After 12 months, excess milk still warrants attention. "Iron deficiency in high milk consumers" is a well-recognized clinical pattern. In a Canadian observational study of 1,311 children aged 2 to 5, higher cow's milk intake was associated with lower serum ferritin (a marker of the body's iron stores); about two cups (roughly 500 ml) a day had minimal effect on iron stores for most children, and the drop in ferritin was steeper in children still drinking from a bottle [6]. The mechanism is circular: milk fills the stomach, crowding out the iron-rich foods (meats, leafy greens) that would otherwise be eaten.

As for amounts, a U.S. beverage consensus statement developed with the AAP suggests 16–24 oz (about 480–720 ml) a day at 12–24 months, up to 16 oz (about 480 ml) at ages 2–3, and up to 20 oz (about 600 ml) at ages 4–5 [7].

Tea — The Difference Between Barley Tea and Green Tea

In the Japanese parenting context, barley tea (mugicha) and green tea are both common. Their profiles are meaningfully different.

Green tea contains both caffeine and tannins: plant polyphenols in tea, such as catechins, that bind to dietary iron in the gut and reduce its absorption. These polyphenols inhibit the absorption of non-heme iron (the form found in vegetables and legumes). In a trial in young women, adding a green tea extract to a meal lowered non-heme iron absorption from an average of 12.1% to 8.9% [8]. From a nutritional standpoint, green tea with meals is worth avoiding; waiting a while after eating before drinking it preserves the iron-absorption opportunity. One trial found that drinking black tea one hour after a meal, rather than with it, did not reduce iron absorption [9] (both studies were in adults, not young children).

Barley tea contains virtually no caffeine and essentially no tannins. This is the basis for its status as the default beverage in Japanese infant care — it is neither a caffeine source nor a nutritional inhibitor. The cultural consensus around barley tea for young children reflects a genuine physiological rationale.

For herbal teas, some varieties contain components unsuitable for infants and young children. Products specifically formulated and labeled for infant use are preferable.

Caffeine — How to Think About the Upper Limit

Japan has not established explicit caffeine limits for children. A useful reference comes from Health Canada [10]:

  • Ages 4–6: 45 mg per day
  • Ages 7–9: 62.5 mg per day
  • Ages 10–12: 85 mg per day

Approximate caffeine content per 150 ml serving: coffee, 90–150 mg; green tea, 20–30 mg; black tea, 30–60 mg.

The 45 mg daily ceiling for 4–6-year-olds is reached by just 1.5–2 cups of green tea. Households where young children regularly drink coffee or black tea should be aware of this.

Practical Takeaways

1. Default to water, plain hot water, and barley tea For children aged 1–3, making water, plain hot water, and barley tea the primary beverages naturally limits excess intake of juice, green tea, and milk. Reserving juice for occasional situations — and keeping the amount within 4 oz — aligns with AAP guidance.

2. Pay attention to how much milk is consumed For children over 12 months who drink a lot of milk, treating about 720 ml at ages 1–2, and 480 ml from age 2, as a rough daily ceiling while maintaining iron-rich foods (meat, leafy greens) in the diet is the key parallel action.

3. Think about what accompanies meals When iron-rich foods are being served, pair them with barley tea or plain water. Saving green tea for a while after the meal (one hour in the study above) preserves the iron-absorption opportunity rather than canceling it.

Summary

The fact that certain "healthy-seeming" drinks are restricted in clinical guidelines may come as a surprise. 100% fruit juice has an upper limit. Too much milk can contribute to iron deficiency. Green tea reduces iron absorption at meals. These are not alarming facts — they are the kind of detail that sharpens daily nutritional decision-making.

Beverages are among the more easily overlooked elements of an infant feeding log. But when you view meals and drinks side by side, the nutritional picture sometimes comes into focus in unexpected ways.

References

  1. Heyman MB, Abrams SA; American Academy of Pediatrics Section on Gastroenterology, Hepatology, and Nutrition; Committee on Nutrition. Fruit juice in infants, children, and adolescents: current recommendations. Pediatrics. 2017;139(6):e20170967. doi:10.1542/peds.2017-0967. PMID: 28562300.
  2. Dennison BA, Rockwell HL, Baker SL. Excess fruit juice consumption by preschool-aged children is associated with short stature and obesity. Pediatrics. 1997;99(1):15–22. doi:10.1542/peds.99.1.15. PMID: 8989331.
  3. American Academy of Pediatrics Committee on Nutrition. The use of whole cow's milk in infancy. Pediatrics. 1992;89(6 Pt 1):1105–1109. PMID: 1594357.
  4. Fewtrell M, Bronsky J, Campoy C, et al. Complementary feeding: a position paper by the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) Committee on Nutrition. J Pediatr Gastroenterol Nutr. 2017;64(1):119–132. doi:10.1097/MPG.0000000000001454. PMID: 28027215.
  5. Ministry of Health, Labour and Welfare (Japan). Guide to Support Breastfeeding and Weaning (2019 revision) [授乳・離乳の支援ガイド]. 2019. https://www.mhlw.go.jp/content/11908000/000496257.pdf
  6. Maguire JL, Lebovic G, Kandasamy S, et al. The relationship between cow's milk and stores of vitamin D and iron in early childhood. Pediatrics. 2013;131(1):e144–e151. doi:10.1542/peds.2012-1793. PMID: 23248224.
  7. Lott M, Callahan E, Welker Duffy E, Story M, Daniels S. Healthy Beverage Consumption in Early Childhood: Recommendations from Key National Health and Nutrition Organizations. Consensus Statement. Durham, NC: Healthy Eating Research; 2019. https://healthyeatingresearch.org/wp-content/uploads/2019/09/HER-HealthyBeverage-ConsensusStatement.pdf
  8. Samman S, Sandström B, Toft MB, et al. Green tea or rosemary extract added to foods reduces nonheme-iron absorption. Am J Clin Nutr. 2001;73(3):607–612. doi:10.1093/ajcn/73.3.607. PMID: 11237939.
  9. Ahmad Fuzi SF, Koller D, Bruggraber S, et al. A 1-h time interval between a meal containing iron and consumption of tea attenuates the inhibitory effects on iron absorption: a controlled trial in a cohort of healthy UK women using a stable iron isotope. Am J Clin Nutr. 2017;106(6):1413–1421. doi:10.3945/ajcn.117.161364. PMID: 29046302.
  10. Health Canada. Caffeine in foods. https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/caffeine-foods.html

In the memori app

The memori app keeps the accumulation of feeds and meals in a form you can read back later.

  • Nursing, pumping and bottles run on a timer, with side and volume recorded alongside.
  • Solids build up into a list of what's been eaten, so a first-time food is easy to spot.
  • Height, weight and head circumference are drawn over national reference curves.
Try memori
← PreviousPicky Eating, Food Refusal, and Mealtime Behavior — A Developmental and Neurological FrameworkNext →Eating Together — What Longitudinal Research Actually Shows About Family Meals

Related

  • Supplementing Iron Through Solid Food — What to Feed, How Much, and How to Maximize Absorption After Six Months
  • Three Sleep Training Methods Compared — Reading the RCTs on Ferber, Cry It Out, and Camping Out
  • Baby-Led Weaning: What the Evidence Actually Shows About Autonomy and Choking Risk