Children with obesity who have recently lost weight are more likely to show hunger-related activity in their brains after a meal, according to research presented at the 60th Annual European Society for Paediatric Endocrinology Meeting. This brain activity, reflecting that they were unsatisfied by their meal, happens even though their gut hormone levels have changed, as expected, to reduce hunger and indicate fullness. This disconnect between food satisfaction in their brain versus their digestive system may underlie why many people regain weight, particularly after a strict diet. Understanding and addressing this persistence of hunger-promoting brain activity could lead to better and more sustainable treatments for obesity in children and adults.
Obesity is a growing worldwide health crisis with an estimated 124 million children affected globally. Obesity in children is often managed through family-based behavioral therapy involving regular outpatient sessions that focus on dietary and physical activity education. The gold standard for such programs is a minimum of 26 contact hours over a six-month period. However, many children regain weight soon after program completion. It is poorly understood why the success rate is so low, so the researchers write that they set out to investigate “relationships between obesity outcomes and changes in brain activation by visual food cues and hormone levels in response to obesity intervention by family-based behavioral treatment (FBT).”
In this study, Christian Roth, MD, of Seattle Children’s Hospital and team compared brain appetite regulation activity with gut hormone responses in children with obesity before and after a 24-week weight loss program. Using functional MRI, they assessed activation patterns in appetite-regulating brain areas in response to high- vs. low-calorie images, after a meal. Gut hormone levels were also assessed before and after meals, at the beginning and end of the program.
At the end of the program, children still showed high levels of activation in brain areas related to appetite, after a meal, in response to food images, indicating that they were hungry. However, their levels of appetite-regulating gut hormones indicated fullness and satiety. Strikingly, the children who lost the most weight, showed the strongest activation in their brains to food cues after a meal, at the end of the program.
The researchers are careful to point out that these findings are from a small group of children tested only at the start and end of the intervention program, so larger and more detailed studies would be needed to confirm this central effect.
“In response to FBT, adaptations of central satiety responses and peripheral satiety-regulating hormones were noted,” the investigators conclude. “After weight loss, changes of peripheral hormone secretion support weight loss, but there was a weaker central satiety response. The findings suggest that even when peripheral satiety responses by gut hormones are intact, the central regulation of satiety is disturbed in children with [obesity] who significantly improve their weight status during FBT, which could favor future weight regain.”