SAN FRANCISCO (CBS SF) – A new study from UCSF and Touro University in Vallejo found obese children who reduced their consumption of added sugar were able to improve their health in as little as 10 days.

Researchers said the 43 children in the study were able to reverse high cholesterol, high blood pressure and other chronic metabolic diseases, despite eating the same amount of calories.

READ MORE: Volunteers Spread Out Across Bay Area for Annual Coastal Cleanup

“This study definitively shows that sugar is metabolically harmful not because of its calories or its effects on weight; rather sugar is metabolically harmful because it’s sugar,” Robert Lustig, the study’s lead author, said in a statement from UCSF.

Researchers supplied the children with food for a nine-day period. The food had reduced sugar, but had the same amount of fats, protein, carbohydrates and calories as they had before the study. All of the food was purchased at local supermarkets and were items that appealed to kids, such as turkey hot dogs and pizza. Fruit was also allowed.

READ MORE: San Francisco Celebrates Rise of Lowrider Community With Car Show and Cruise

After about a week-and-a-half, the researchers found insulin levels in the children had dropped by one-third. Diastolic blood pressure dropped by 5mm and LDL or “bad” cholesterol had dropped by 10 points.

The research will appear in the February 2016 issue of the Journal Obesity.

Earlier this year, researchers at UC Davis found young men and women who consumed drinks with high fructose corn syrup showed increased risk factors for cardiovascular disease in as little as two weeks.

MORE NEWS: San Francisco Schools, Public Health Dept. Partner to Provide Campus COVID Vaccinations

The World Health Organization recommends the intake of added sugars (.pdf) should be less than 10 percent and preferably below 5 percent of total energy intake.