Added sugar: how much is too much

The major health bodies that have set a limit on added sugar land in roughly the same place: less than 10 percent of daily calories, which is about 50 grams, or 12 teaspoons, for someone eating 2,000 calories a day. The World Health Organization makes this a strong recommendation and adds a conditional suggestion that going below 5 percent, about 25 grams a day, would bring additional benefit (World Health Organization). The American Heart Association sets a lower bar still, and the newest U.S. Dietary Guidelines have moved from a daily percentage to a cap of 10 grams per meal.

Most American adults are well above all of these lines. Average intake in 2017 and 2018 was about 17 teaspoons of added sugar a day, roughly 68 grams, with men averaging 19 teaspoons and women 15 (Centers for Disease Control and Prevention). The evidence behind the limits is strongest for weight gain and tooth decay, where randomized trials exist, and rests on observational cohorts for heart disease and type 2 diabetes.

This article is for adults who want a number to aim for, and for anyone trying to work out what the figure on a food label means.

What counts as added sugar

Added sugars are sugars put into a food during processing or at the table, plus the sugars in syrups, honey, and concentrated fruit or vegetable juice. They do not include the sugar naturally present in whole fruit, vegetables, or plain milk (U.S. Food and Drug Administration). The WHO uses the slightly broader term free sugars, which also counts the sugar in fruit juice; the practical difference is that a glass of orange juice counts toward the WHO limit but a whole orange does not (World Health Organization). The distinction matters because the evidence for harm comes mainly from studies of sweetened drinks and processed foods, not fruit.

The limits set by major bodies

• WHO (2015): free sugars below 10 percent of total energy for adults and children, rated a strong recommendation. A further cut to below 5 percent, roughly 25 grams or 6 teaspoons a day, is a conditional recommendation based on more limited evidence (World Health Organization).
• American Heart Association (2009): no more than 100 calories a day from added sugar for most women and 150 for most men, which at 4 calories per gram is about 25 and 38 grams. The statement noted that in 2001 to 2004 Americans averaged 22 teaspoons a day (Johnson et al., 2009).
• FDA Nutrition Facts label: the Daily Value for added sugars is 50 grams, based on 2,000 calories a day. A food with 5 percent of the Daily Value or less per serving is considered low in added sugar, and one with 20 percent or more is high (U.S. Food and Drug Administration).
• Dietary Guidelines for Americans, 2025 to 2030: no more than 10 grams of added sugar in a meal, no added sugar in infancy and early childhood, no amount recommended for children aged 5 to 10, and a direction to avoid sugar-sweetened beverages such as sodas, fruit drinks, and energy drinks (U.S. Departments of Agriculture and Health and Human Services).

These are not contradictory. Three meals at the per-meal cap come to 30 grams a day, between the WHO's 5 and 10 percent lines. A reasonable adult target is under 50 grams a day, with 25 to 35 grams as a better goal, and no more than about 10 grams at any one meal.

What the evidence shows for weight

The clearest trial evidence concerns body weight. A systematic review commissioned to inform the WHO guideline pooled 30 randomized trials and 38 cohort studies. In trials where adults ate freely, cutting sugar intake lowered body weight by an average of 0.80 kilograms, and raising it increased weight by a comparable 0.75 kilograms. When sugar was swapped for the same calories from other carbohydrates, weight did not change, which suggests sugar affects weight by raising total calorie intake rather than through a special metabolic effect. In cohort studies of children, those with the highest intake of sugar-sweetened drinks had 55 percent higher odds of being overweight or obese after a year than those with the lowest (Te Morenga et al., 2012). The effects are modest in size; the concern is that they accumulate over years.

Heart disease and diabetes

The evidence here is observational and should be read as association rather than proof. In a nationally representative cohort of 11,733 U.S. adults followed for a median of 14.6 years, people who got 10 to 24.9 percent of calories from added sugar had a 30 percent higher risk of dying from cardiovascular disease than those under 10 percent, after adjustment for diet quality, weight, and other factors. For the roughly 10 percent of adults who got a quarter or more of their calories from added sugar, the risk was nearly tripled. At the time, 71.4 percent of adults were over the 10 percent line (Yang et al., 2014).

For type 2 diabetes, a meta-analysis of 17 prospective cohorts found that each additional daily serving of sugar-sweetened drinks was associated with an 18 percent higher incidence, and 13 percent after accounting for body weight, meaning the link is not explained by weight gain alone. The same analysis found associations for diet drinks and fruit juice, but judged those results more likely to reflect bias (Imamura et al., 2015). Sweetened drinks are the most consistently implicated source, which is why nearly every guideline singles them out.

Tooth decay is the other outcome with direct evidence. The WHO reports higher rates of dental caries when free sugars exceed 10 percent of energy, and this, with weight, is the basis of its strong recommendation. The 5 percent figure rests on three national studies and a historical natural experiment in which sugar availability fell sharply and caries declined, which is why it carries the weaker conditional rating (World Health Organization).

Where it comes from and how to cut it

Sugar-sweetened beverages, desserts, and sweet snacks are the main sources in the American diet (Centers for Disease Control and Prevention). One regular soda can use up most of a day's allowance on its own, and flavored yogurts, cereals, granola bars, sauces, and coffee drinks add amounts that are easy to overlook.

• Read the Added Sugars line, not Total Sugars. Plain yogurt shows sugar from lactose with zero added; a flavored version might show 15 grams total, of which 7 are added (U.S. Food and Drug Administration).
• Use the 5 percent and 20 percent Daily Value cutoffs on labels to sort low from high products quickly.
• Replace sweetened drinks first. This change has the most consistent support in the research and is usually the largest single cut.
• Do not count whole fruit. Fruit juice, honey, maple syrup, and agave all count.

Who should be careful

People with diabetes or prediabetes should discuss sugar and carbohydrate targets with their doctor or a dietitian, since the general limits here are not a treatment plan. Parents should note that current U.S. guidelines recommend no added sugar for young children, and that trials of advice to reduce sugar in children have had poor compliance, which suggests changing what is in the house works better than instructions (Te Morenga et al., 2012). Anyone switching to non-sugar sweeteners should know that the evidence on their long-term benefit is mixed and that the cohort data above did not show diet drinks to be a clearly healthy alternative.

Sources

• WHO calls on countries to reduce sugars intake among adults and children (World Health Organization, 2015) — summary of the WHO sugars intake guideline and its evidence basis
• Dietary Guidelines for Americans, 2025–2030 (U.S. Departments of Agriculture and Health and Human Services) — current U.S. federal dietary guidance
• Added Sugars on the Nutrition Facts Label (U.S. Food and Drug Administration) — U.S. government reference on the label definition and Daily Value
• Get the Facts: Added Sugars (Centers for Disease Control and Prevention) — U.S. government summary of national survey intake data
• Dietary sugars intake and cardiovascular health: a scientific statement from the American Heart Association (Johnson et al., Circulation, 2009) — expert scientific statement setting the 100 and 150 calorie limits
• Dietary sugars and body weight: systematic review and meta-analyses of randomised controlled trials and cohort studies (Te Morenga et al., BMJ, 2012) — systematic review of 30 randomized trials and 38 cohort studies
• Added sugar intake and cardiovascular diseases mortality among US adults (Yang et al., JAMA Internal Medicine, 2014) — prospective cohort, n=11,733, median 14.6 years
• Consumption of sugar sweetened beverages, artificially sweetened beverages, and fruit juice and incidence of type 2 diabetes (Imamura et al., BMJ, 2015) — meta-analysis of 17 prospective cohorts