Too much meat can make children fat, study finds

High intake of protein in early childhood, particularly from animal sources, is associated with a higher body mass index (BMI), according to new research carried out in the Netherlands. 

The optimal levels of consumption remain unknown, but the results could have implications for protein levels in infant formula and foods for toddlers.

Kids are getting fatter, that much we know. But what role does childhood diet play in controlling body fat levels and managing weight?

Previous studies have suggested that a high protein diet during infancy and early childhood leads to a higher BMI. But these didn’t consider whether the extra weight gained was in the form of lean mass, as has been observed in adults, or if it led to obesity

Research has also shown that regular intake of certain plant foods may prevent weight gain in children and adolescents.

Dr Trudy Voortman and colleagues at the Erasmus University Medical Centre in Rotterdam, the Netherlands have presented new research suggesting that too much meat early on in life can lead to obesity.

The team studied 3,564 Dutch children whose dietary intake was assessed using food-frequency questionnaires at the age of one. From that, the researchers calculated intakes of total protein, protein from different sources; of total carbohydrates, polysaccharides, monosaccharides, and disaccharides; and of total saturated, monounsaturated and polyunsaturated fat.

Participants had their height and weight repeatedly measured between the ages of one and 10, while fat (fat mass índex, FMI) and fat-free masses (fat-free mass índex, FFMI) were assessed using dual x-ray absorptiometry (DXA) scanning at age six and 10.

The data were adjusted to take account of variables such as maternal age and education, the child’s ethnicity, total energy intake, whether or not the child was breastfed, and physical activity levels.

Less meat, please

The team found that a higher intake of both total and animal protein (from dairy and non-dairy sources) was associated with being taller, heavier, and having a higher BMI up to the age of 10. This was true regardless of whether protein was replacing carbohydrates or fats in the diet.

Further analysis showed that the association between high protein intake and high BMI could be explained entirely by increases in FMI with no increase in FFMI, as may be expected in adults.

“Our results suggest that high protein intake, particularly from animal food sources, in early childhood is associated with higher body fat mass, but not fat-free mass,” the team explained, when they presented the results at the recent Congress on Obesity in Porto, Portugal.

The team published some of the results last year in a paper for the International Journal of Obesity in March 2016. At the time they concluded that “a reduction in protein intake in infancy and early childhood may thus be advised to prevent obesity, for example, by lowering the amounts of protein in infant formula and toddler foods”.

The authors recommended more research in order to examine the optimal range of protein intake and macronutrient composition of the diet for infants and young children.