Any parent can testify that kids have the craziest eating habits.
At one meal, a child will eat as if he hasn't seen food in days. Next meal, the plate will barely be touched.
On Monday morning, bananas and corn flakes might be all the rage. On Tuesday, those same foods head the "I hate" list.
Now comes a study in the New England Journal of Medicine that shows that eating patterns of pre-schoolers might not be as chaotic as they seem.
By measuring the food intake of 15 pre-schoolers, researchers found that even though a child's appetite can fluctuate dramatically from meal to meal, the total number of calories consumed each day is fairly constant.
The researchers, from the University of Illinois at Urbana-Champaign, suggested that parents might be wise to avoid the "use of threats and bribes and of rewards or punishment" to get their kids to finish their meals, since children seem to have an innate ability to get all the nourishment they need to grow.
"Although children's food consumption is highly variable from meal to meal, daily energy intake is relatively constant, because children adjust their energy intake at successive meals," the researchers concluded. "High energy intake at one meal was often compensated for by low energy intake at the next, and vice versa."
The research team, lead by developmental psychologist Leann L. Birch, concluded, "The successful feeding of children is best accomplished by providing them with a variety of healthful foods and allowing them to eat what they wish."
In an editorial accompanying the study, Dr. Gilbert Forbes, a pediatrician at the University of Rochester (N.Y.), said the study demonstrated that "there is a good deal of order to be found, if one looks carefully, in the midst of what seems to be nutritional chaos."
He also noted that even though the children in the research project were allowed to eat as much as they wanted, they did not eat to excess.
"In this they were wiser than many adults, for whom a plethora of food is but a passport to obesity," he wrote.
The 15 children, ages 2 to 5, could choose whatever food they wanted from a set menu the researchers provided on each of the six days of the study. The children were offered a selection that included such kid-pleasing fare as macaroni and cheese, and peanut-butter-and-jelly sandwiches.
"For each child, energy intake at a given mealtime was highly variable," the researchers reported. For instance, a child might consume 100 calories at one breakfast and 350 calories at another, even though they were offered the same foods at each of the meals.
The researchers calculated that the number of calories consumed at any given meal varied on average by 33 percent from one day to the next. But when each of the children's calories were added up for a 24-hour period, the total amount of calories consumed varied on average just 10 percent from day to day.
The researchers said their findings support a previous suggestion of "the existence of some orderly control mechanism" that keeps children's appetites in line with what is needed to sustain good growth.
The Illinois researchers didn't measure whether the children got all the vitamins and minerals they needed from the foods they selected, although the menus offered were designed to meet the recommended dietary allowances, or RDAs, for children their age.
The study builds on classic nutritional research conducted in the 1920s and 1930s by pediatrician Clara Davis. She, too, found that when children were allowed to eat what they wanted from an assortment of foods, their eating habits were unpredictable and sometimes strange but nevertheless enough to sustain good growth and health.