Protein Intake from Birth to 2 Years and Obesity Outcomes in Later Childhood and Adolescence: A Systematic Review of Prospective Cohort Studies

Abstract

Emerging evidence shows an association between protein intake during infancy and later obesity risk, and that association may differ by protein sources. This systematic review summarized and evaluated prospective cohort studies assessing the long-term association of total protein intake and protein sources during infancy (from birth to 2 y) with subsequent obesity outcomes in childhood or adolescence. Literature searches were conducted in Embase, Medline, Scopus, and Web of Science. Sixteen studies that reported associations between total protein intake and/or protein intake from different sources from birth to 2 y and ≥1 obesity outcomes in childhood or adolescence from 9 cohorts were identified. Most studies (11/16) were rated as high quality. The most frequently reported association was total protein intake and BMI (up to 10 y) with 6 out of 7 cohorts showing significant positive associations. Similar associations were found for animal protein, but not for plant protein. Limited studies examined the association between protein intake (both total and sources) and body composition (body fat, fat mass, and fat-free mass) and revealed inconsistent findings. Overall, higher intakes of total and animal protein during infancy were associated with higher BMI in childhood and adolescence. Future studies investigating the contribution of protein sources in long-term obesity development are needed. This review was registered at PROSPERO as CRD42020166540.

Protein intake in children and growth and risk of overweight or obesity: A systematic review and meta-analysis

“…More recently, Stokes et al reviewed the association between protein intake in infants and children up to 2 years of age and childhood obesity-related outcomes in a systematic review including only prospective cohort studies ( 8 ). Several studies included in this review were also included by Stokes et al ( 30 – 32 , 34 , 35 , 38 – 42 , 45 , 46 , 48 ), and they performed a meta-analysis on total protein intake and BMI with three of the five studies included in our meta-analysis, obtaining similar results.…”

“…Although an adequate amount and quality of dietary protein is crucial for growth, a very high-protein diet in infancy may accelerate growth and increase the likelihood of overweight and obesity in childhood and later in life (4)(5)(6)(7)(8). A systematic review of the Nordic Nutrition Recommendations (NNRs) for 2012 revealed that there was convincing evidence for an effect of higher protein intake in infancy and early childhood on increased growth and higher body mass index (BMI) later in childhood (5).…”

Burden of Early Life Obesity and Its Relationship with Protein Intake in Infancy: The Middle East Expert Consensus

“…Several original studies indicated that high protein formula can result in accelerated weight gain, higher BMI, and increased body-fat, which in turn, exacerbate the risk of adulthood obesity [ 66 87 89 90 98 99 ]. The results of these studies have recently been validated by meta-analyses, which reached the same conclusion [ 91 92 ]. With rates of childhood obesity continuing to increase, early metabolic programming is becoming an area of interest for researchers in the field [ 66 ].…”

“…Recent meta-analyses support the data from these original studies, with both Pimpin et al [ 91 ] and Stokes et al [ 92 ] confirming a positive association between high protein intake in the early years and increased weight gain/higher BMI in the months and years that follow. The first of these analyses compared the effects of high protein formula with low protein formula across 24 studies.…”

“…The net result was a significant increase in weight (weighted mean difference) of 0.14 kg upon supplementation with high protein formula [ 91 ]. In the second meta-analysis, ten studies, representing six cohorts of formula-fed infants, reported a significant positive association ( p <0.05) between total protein intake from birth to 2 years of age and BMI or BMI z score up to the age of 10 [ 92 ].…”