While most of us monitor dietary fat intake, these restrictions are eased for children under two. “Limiting fats is not as important for children under two as it is for adults and older children,” advises pediatrician Michael Nicholas, MD. “Fats are crucial fuel for the rapid growth and brain development that occur in those two years.” Fats are important ingredients of myelin, a protective tissue that surrounds budding nerves.

Once kids grow out of this stage, experts recommend the same dietary fat ratios that adults follow. Rather than measuring dietary fat amounts, however, Dr. Nicholas recommends modeling nutritious choices and healthy pursuits like exercise. “Starting good habits early is easier than correcting bad habits later,” he says.

Even adolescents experiencing growth spurts should maintain sound food choices and sensible dietary fat ratios. Though they may take in 4,000 calories daily during these short periods, junk food isn’t a good source for the extra energy.