Liver Fat Content, Not Body Weight, Determines Health Outcomes in Children With Obesity: Israeli Research Findings

The study reveals that obesity in children doesn't necessarily indicate poor health outcomes.

Tel Aviv:

Israeli scientists announced Sunday that groundbreaking research demonstrates liver fat, rather than body weight, serves as the primary predictor of health complications in children with obesity.

Research conducted by Tel Aviv University in collaboration with Dana Dwek Children's Hospital challenges conventional assumptions about childhood obesity. The findings suggest that excess weight alone doesn't automatically lead to poor health outcomes. Instead, researchers identified liver fat accumulation as the critical factor in determining which obese children develop serious health conditions. Children with fatty liver face increased risks of type 2 diabetes, hypertension, cardiovascular disease, and potentially liver cirrhosis as they age.

The research team studied 31 Israeli children with obesity to investigate why certain individuals develop metabolic complications while others remain healthy despite excess weight. Their investigation revealed that children already exhibiting signs of illness had livers containing approximately 14 percent fat—more than double the 6 percent found in obese children who maintained metabolic health.

"This is a cross-sectional study, which means we looked at the children thoroughly at one point in time rather than following them over the years," explained doctoral student Ron Sternfeld. "We can only indicate correlation, not causation, but the results are striking. They show that some children with obesity can remain metabolically healthy despite their weight."

The researchers employed advanced magnetic resonance spectroscopy (MRS) to measure liver fat non-invasively during MRI procedures, representing one of few studies applying this methodology to pediatric populations. In addition to MRS, the team conducted comprehensive medical evaluations and analyzed children's medical histories beginning from prenatal development.

Notably, other factors commonly associated with metabolic risk, including visceral fat surrounding internal organs, showed no significant differences between healthy and unhealthy children. "We checked many different criteria and found no difference between the two groups," Sternfeld noted. "The biggest difference was liver fat. Fatty liver—more than 5.5 percent fat in the liver—is linked to diabetes, high blood pressure, sleep apnea, and more. To our surprise, some obese children do not have fatty liver."

Professor Yftach Gepner, who directed the study, emphasized that these findings shift focus from weight management alone toward dietary quality. "Children who were already ill consumed more sodium, processed foods, and certain saturated fats from animal protein—mainly red meat," Gepner explained. "This suggests that protecting liver health through diet can help prevent metabolic illness, even if a child remains obese. A Mediterranean-style diet may offer significant protection."

Prenatal factors also appeared influential. Children in the "unhealthy obesity" category were three times more likely to have been born following high-risk pregnancies compared to their healthier counterparts, highlighting complex interactions between early-life development and subsequent metabolic health.

"We found that children with obesity can be healthy," Gepner stated. "Even if reducing food intake or weight is difficult, we can still protect their health by improving the nutritional quality of their diet and reducing liver fat. The liver is the most important metabolic organ, and monitoring it should be central to preventive medicine."

The research offers practical approaches to protecting children with obesity. Enhancing dietary quality by reducing processed foods, sodium, and saturated fats can limit liver fat accumulation. Early screening using non-invasive imaging techniques can identify at-risk children, while targeted interventions including nutritional counseling and physical activity guidance may help prevent diabetes, hypertension, and other obesity-related conditions.