Sugar

Studies in people

• Concern

  Heart and metabolic health²

  Eating lots of sugar, especially in sugary drinks, is linked to weight gain and heart problems.

• Concern

  Heart and diabetes risk³

  Eating too much sugar may raise the risk of heart disease and type 2 diabetes, but this is still debated.

• Concern

  Heart and liver health⁴

  In people, sugar-sweetened drinks were linked to higher risks of heart disease, type 2 diabetes and liver disease.

• Concern

  Type 2 diabetes risk⁵

  People who drank the most sugar-sweetened drinks had a higher risk of type 2 diabetes.

• Open question

  Stroke and dementia risk⁶

  In this study, sugar-sweetened drinks were not linked to stroke or dementia, though diet drinks were.

• Concern

  Weight gain and obesity⁸

  Drinking sugar-sweetened drinks like soda is linked to weight gain and obesity in children and adults.

• Concern

  Weight and dental health⁹

  Sugary drinks and added sugars raise the risk of overweight and tooth decay in children.

• Concern

  Cancer death risk¹⁰

  Drinking two or more sugar-sweetened drinks a day was linked to higher death rates from colorectal and kidney cancers.

• Concern

  Children's tooth decay¹¹

  In Kenya, children's tooth decay rose alongside growing sugar consumption, though scientists say longer studies are needed to confirm the link.

• Open question

  Weight and waist size in children¹²

  In preschool-aged children, sugar intake was not linked to weight or other body measures, except a weak link to waist size.

• Concern

  Long-term health effects¹³

  Eating lots of sugar is linked to obesity, diabetes, heart disease and other long-term health problems.

• No harm found

  Fertility treatment success¹⁴

  In women having fertility treatment, drinking sugar-sweetened drinks made no difference to whether treatment worked.

• Open question

  Attention and mood¹⁶

  In healthy young adults, high-fructose corn syrup helped sustained attention, but expecting sugar only made people feel more tense.

• Concern

  Obesity and diabetes risk¹⁷

  Sweet drinks like sugar-sweetened beverages are linked to obesity and diabetes, though scientists do not yet know exactly how.

• Concern

  Childhood body fat¹⁸

  In UK children, drinking sugar-sweetened drinks daily was linked to gaining more body fat between ages 7 and 11.

• Concern

  Teen metabolic risk¹⁹

  In teens, drinking sugar-sweetened beverages was linked to higher blood sugar, insulin and waist size.

• Open question

  Obesity and high blood pressure²⁰

  Countries where people eat more sugar tend to have more obesity and high blood pressure.

• Concern

  Children's sleep and sugary drinks²¹

  Kids who drank regular soft drinks with sugar daily slept about 12 minutes less a night than those who rarely did.

Animal and lab studies only

• Concern

  Drug-like effects²⁸

  In animal studies, sugar caused drug-like effects such as bingeing, craving, and withdrawal.

• Concern

  Appetite after meals³⁰

  In animal studies, sugar turned on brain cells in full mice that made them want more sugar.

Study type not stated

• Concern

  Brain reward and overeating²²

  Eating too much sugar may change the brain's reward system, leading to compulsive overeating.

• Concern

  Body-wide inflammation²³

  Eating lots of sugar may add to body-wide inflammation, but scientists do not yet know for sure in people.

• Concern

  Liver fat buildup²⁴

  Diets high in sugar and high-fructose corn syrup are linked to fat building up in the liver.

• Concern

  Skin aging²⁵

  Sugar links collagen fibers in your skin, making them harder to repair, and sunlight speeds this up.

• Concern

  Mood and addiction risk²⁶

  Eating lots of sugar may make children more anxious, depressed and prone to addiction later.

• Open question

  Cravings and addiction²⁷

  Scientists are asking whether sugar can be addictive, and what that would mean for food rules.

How it’s made and used

• Kids' sugary drink intake⁷

  In Chilean children, sugar-sweetened drinks still made up a big share of daily calories before newer rules took effect.

• Sugary drink sales trends¹⁵

  Sales of sugar-sweetened drinks in Australia fell as shoppers chose non-sugar options instead.

• Gut sensing and appetite²⁹

  In animal studies, sugar is sensed in the gut, which may affect how much sugar animals want.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.