(HealthDay News) — Cutting most of the sugar from a child’s diet can rapidly improve metabolic health, even if the diet still contains the same amount of calories and carbohydrates as before, a new study suggests. 

The study was published in Obesity.

Robert Lustig, MD, a pediatric endocrinologist at University of California, San Francisco, Benioff Children’s Hospital, and colleagues assigned a group of 43 obese children aged 8 to 18 years with at least 1 other metabolic issue to a 9-day diet that severely restricted sugar intake, but replaced added sugars with starchy foods to maintain the children’s intake of calories and carbohydrates. 

Continue Reading

The researchers provided the study participants with 9 days of food, including all snacks and drinks.

The children consumed the same amount of carbohydrates, but their total dietary sugar intake dropped from 28% to 10%. 

After 9 days on the sugar-restricted diet, virtually every aspect of the participants’ metabolic health improved without a significant change in weight, the researchers found. Blood pressure began to move toward normal, and levels of triglycerides and LDL cholesterol decreased. Fasting blood glucose went down by 5 points, and insulin levels were cut by one-third.

“Every aspect of their metabolic health got better, with no change in calories,” Dr Lustig told HealthDay. “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.”


  1. Lustig RH, Mulligan K, Noworolski SM, et al. Isocaloric fructose restriction and metabolic improvement in children with obesity and metabolic syndrome. Obesity. 2015;doi:10.1002/oby.21371.