Food · 5 min read ·

Sugar: how much is too much?

It's in soft drinks, yoghurts and even ketchup. Is it harmful in itself, or does it just add calories? And does it really make kids hyper?

In a nutshell

1Which sugar counts

Not all sugar counts the same. The recommendations are about so-called free sugars.

WHO definition free sugars = sugars added to food and drinks by the manufacturer, the cook or you, plus the sugars in honey, syrups and fruit juices. Sugars naturally present in whole fruit, vegetables and milk don't count — no harmful effects have been shown for them.1

2How much is too much

WHO recommendation less than 10% of daily energy from free sugars is what the World Health Organization recommends for adults and children. Cutting it below 5% — for an adult roughly 25 g, or about 6 teaspoons — would bring further benefits, though this second step is only a conditional recommendation.1
Strong evidence as little as possible In 2022 the European Food Safety Authority (EFSA) assessed how much sugar is still safe. Its conclusion: intake of added and free sugars should be as low as possible, as long as the diet is otherwise nutritionally adequate.2

3Sugar and weight

Strong evidence −0.8 kg A summary of randomised trials: when adults ate less sugar, they lost 0.8 kg on average; when they ate more, they gained 0.75 kg. But when sugar was swapped for other carbohydrates with the same calories, weight didn't change — so sugar affects weight mainly through extra calories.3
Moderate evidence +18% In observational studies, each daily serving of a sugary drink was linked to an 18% higher risk of type 2 diabetes — 13% once excess weight was taken into account.4

4Teeth

Moderate evidence fewer cavities A systematic review for the WHO: there is less tooth decay when free sugars make up less than 10% of energy. A link also showed up below 5%, but the evidence for it was very weak.5

5Myth: sugar and hyper kids

Moderate evidence 23 experiments A summary of placebo-controlled experiments: sugar did not affect children's behaviour or concentration. According to the authors, parents' strong belief may come from expectation — though a small effect in some children cannot be ruled out.6

Related articles: Sweeteners, Fibre.

What to take from this

Sources

Written on , based on studies available at that date. Newer research may change the conclusions.

  1. World Health Organization (2015). Guideline: Sugars intake for adults and children. Geneva: WHO. who.int/publications/i/item/9789241549028
  2. EFSA NDA Panel (2022). Tolerable upper intake level for dietary sugars. EFSA Journal 20(2):7074. doi.org/10.2903/j.efsa.2022.7074
  3. Te Morenga L., Mallard S., Mann J. (2013). Dietary sugars and body weight: systematic review and meta-analyses of randomised controlled trials and cohort studies. BMJ 346:e7492. doi.org/10.1136/bmj.e7492
  4. Imamura F. et al. (2015). Consumption of sugar sweetened beverages, artificially sweetened beverages, and fruit juice and incidence of type 2 diabetes: systematic review, meta-analysis, and estimation of population attributable fraction. BMJ 351:h3576. doi.org/10.1136/bmj.h3576
  5. Moynihan P. J., Kelly S. A. M. (2014). Effect on caries of restricting sugars intake: systematic review to inform WHO guidelines. Journal of Dental Research 93(1):8–18. doi.org/10.1177/0022034513508954
  6. Wolraich M. L. et al. (1995). The effect of sugar on behavior or cognition in children: a meta-analysis. JAMA 274(20):1617–1621. doi.org/10.1001/jama.1995.03530200053037
  7. Regulation (EU) No 1169/2011 on the provision of food information to consumers, Annex I (definition: “sugars” means all monosaccharides and disaccharides present in food, excluding polyols). eur-lex.europa.eu

This is general information and does not replace a doctor or dietitian. If you have diabetes, ask your doctor about your carbohydrate intake.