High intakes of skimmed milk, but not meat, increase serum IGF-I and IGFBP-3 in eight-year-old boys

Eur J Clin Nutr. 2004 Sep;58(9):1211-6. doi: 10.1038/sj.ejcn.1601948.


Objective: To examine whether a high protein intake (PI) from either milk or meat, at a level often seen in late infancy, could increase s-IGF-I and s-IGF-I/s-IGFBP-3 in healthy, prepubertal children. IGF-I levels are positively associated with growth velocity in children and some studies suggest that a high animal PI can stimulate growth. During protein deprivation IGF-I decrease, but it is unknown whether a high PI can increase s-IGF-I in well-nourished children.

Design: In all, 24 8-y-old boys were asked to take either 1.5 l of skimmed milk (n = 12) or the same amount of protein as 250 g low fat meat (n = 12) daily for 7 days. The remaining diet they could choose freely. At baseline and after 7 days, anthropometrical variables were measured, diet was registered (3-day weighed records), and s-IGF-I and s-IGFBP-3 (RIA) were determined after fast.

Results: PI increased by 61% in the milk group to 4.0 g/kg/day (P < 0.0001) and by 54% in the meat group to 3.8 g/kg/day (P = 0.001). The high milk intake increased s-IGF-I by 19% (P = 0.001) and s-IGF-I/s-IGFBP-3 by 13% (P < 0.0001). There were no increases in the meat group.

Conclusions: High intake of milk and not meat, increased concentrations of s-IGF-I and s-IGF-I/s-IGFBP-3 significantly. Compounds in milk and not a high PI as such seem to stimulate IGF-I. This might explain the positive effect of milk intake on growth seen in some studies.

MeSH terms

  • Animals
  • Anthropometry
  • Child
  • Diet Records
  • Dietary Proteins / administration & dosage*
  • Energy Intake
  • Growth / drug effects*
  • Humans
  • Insulin-Like Growth Factor Binding Protein 3 / blood
  • Insulin-Like Growth Factor Binding Protein 3 / metabolism*
  • Insulin-Like Growth Factor I / metabolism*
  • Male
  • Meat*
  • Milk* / chemistry


  • Dietary Proteins
  • Insulin-Like Growth Factor Binding Protein 3
  • Insulin-Like Growth Factor I