A Child's Weight May Be Partly Biology, Even at Age 4

Your Child's Weight May Be Partly About Biology, Even at Age 4

The brain differences linked to it appear years earlier than scientists had documented before, and the researchers say it is no reason to change how you feed her, or to blame yourself.

If you have ever quietly wondered whether your young child's weight is something you caused, a new study offers a measure of relief. Researchers at Florida International University report that in children as young as 4, a higher body mass index was linked to differences in several brain regions that manage reward, motivation, taste, craving and hunger. The finding suggests early childhood weight is shaped partly by biology, not just willpower or a parenting failure.

The finding, published in the peer-reviewed journal Scientific Reports, comes from brain scans of 159 children between the ages of 4 and 7. The team used an advanced MRI method called Restriction Spectrum Imaging, which reads fine details of brain tissue, and of the body measures they tested, BMI, waist circumference and body fat percentage, only BMI tracked with those brain differences. A small signal also appeared in the hypothalamus, which helps regulate hunger, though the researchers say that particular result still needs to be confirmed by later research.

The study describes a connection, not a cause. It captured a single point in time, so it cannot tell whether the brain differences came before shifts in weight, followed them, or shaped each other.