Protein in Infant Formula and Obesity Risk

The nefarious operation on our shape and eating too much protein might start early in life. Could lower protein intake possibly prevent childhood obesity? That is the contention of some authors from Amsterdam. (Why do they have to write in English. They must hate that.) Their recent report (1) finds that the increased protein in baby formula compared to breast milk may be a smoking gun.

It is widely acclaimed that breast milk is the best way to feed babies. But among the benefits of breast milk cited by these authors, I thought that prevention of obesity was a largely discredited idea. I’ll have to go back and rehash that argument again later. But the observation that cow’s milk based formulas have higher protein, and so proportionally less fat and sugar, and the fact that the protein concentration in breast milk decreases over the weeks of lactation, while the protein concentration of infant formulas obviously remains constant, make you wonder what God intended. It has been shown that protein intake during the first 6 months of life is up to 66-70% higher in formula-fed infants compared to breastfed infants. It has also been reported that premature babies fed fortified formula, fortified with both protein and calories, does result in faster weight and head circumference gains during the first and second year of life. Premature babies are the ones we worry about most when it comes to weight gain. However there is evidence that even though they grow faster on fortified formulas they eat less of it and so they don’t actually eat more calories, just more protein. Or it could be that eating more concentrated calories saves on the energy of eating.

Whether or not breast feeding really prevents obesity this contention about protein remains contentious. Among the problems are the fact that the studies are short term. Will it lower the rates of obesity in adults to feed them lower protein as infants? Exclusive breast or formula feeding mostly only happens before 6 months of age. After that the diets of kids get way more complicated and uncontrollable. Will this tiny window of opportunity really make that much difference? We really have to be careful manipulating the diets if innocent tiny babies, as opposed to the huge uncontrolled experiment foisted on us all since baby formula feeding became popular in the 1950s. Back in the really olden days if you couldn’t breast feed or if you were rich, you got a wet nurse for your baby. That must have been some kind of slavery to be a wet nurse.

In 1988 The American Academy of Pediatrics (AAP), being American, had promulgated that the weight gain rate is the single most valuable component of the clinical evaluation of infant formula. We have traditionally esteemed weight gain in babies. However, the higher weight gain rate in formula-fed infants during the first months of life compared to breastfed infants might be the cause of higher weight-for-length, BMI, and obesity risk in later life. Therefore, it might be desirable to lower the weight gain rate of formula-fed infants. And there is movement afoot in Europe to recommend lower protein in formula to do that.

Or you might just avoid all this sticky wicket and breast feed your babies. They discuss lots more intriguing aspects of these questions in this very readable article. Find it and read it.

1. Kouwenhoven SMP, Muts J, Finken MJJ, Goudoever JBV. Low-Protein Infant Formula and Obesity Risk. Nutrients. 2022 Jun 30;14(13):2728. doi: 10.3390/nu14132728. PMID: 35807908; PMCID: PMC9268498.

John DiTraglia M.D. is a Pediatrician in Portsmouth. He can be reached by e-mail- [email protected] or phone-354-6605.