Feeding toddlers fortified milk or red meat can improve their levels of iron, critical for brain development, researchers say.
Researchers from Otago University changed what 225 South Island toddlers ate for five months.
Placing them on a diet featuring either fortified milk or red meat seemed to stop dropping iron levels.
The group of children was split into three groups -- some were fed red meat dishes twice a day, another group was given iron-fortified powdered milk, while a third group was given non-fortified powdered milk.
The researchers measured the protein ferritin, which indicated levels of iron in the blood, at the start and end of the five-month experiment.
The levels for the children drinking the fortified milk increased 44 percent, while they stayed about the same for those fed red meat and fell for those on regular milk powder.
Researcher Anne-Louise Heath said about one in three New Zealand toddlers had low iron levels, which could lead to anaemia.
Specifically, the meat-eating tots were fed lean beef mince, "not because there was a problem with them having too much fat, but because they don't eat much and we wanted to maximise the nutrients in each serving," Dr Heath told NZPA.
Iron deficiency could slow brain development, impair cognitive function and cause behavioural problems, she said.
Though often thought of as an adult food, mince was a better option for young children than luncheon meat and sausages.
Dr Heath said the body of rapidly-growing two-year-olds required large amounts of iron, though little research had yet been conducted into nutrition of toddlers.
"They really are the lost age group. There is lots of research into infant nutrition, but not much at all available for slightly older children."
Using iron-fortified milk could be introduced without much disruption to most toddlers' diets, though it was expensive and could delay the child's transition to an adult diet, she said.
By comparison, meat was cheaper, and only required a small amount of extra food -- about 25 grams, or two heaped tablespoons -- to stop falling iron levels.
It also helped their transition into more adult-style eating, and gave them access to other nutrients.
"If, for example, a toddler was eating a lasagne, they would get the nutrients in the tomato sauce, and so on," Dr Health said.
The results of the study were published in the American Journal of Clinical Nutrition today.