To
study the effects of repeated, infancy-onset dietary counseling on a
detailed metabolic profile. Effects of dietary saturated fat replacement
on circulating concentrations of metabolic biomarkers still remain
unknown.

The
Special Turku Coronary Risk Factor Intervention Project (STRIP) study
is a longitudinal, randomized atherosclerosis prevention trial in which
repeated dietary counseling aimed at reducing the proportion of
saturated fat intake. Nuclear magnetic resonance metabolomics quantified
circulating metabolites from serum samples assessed at age 9 (n = 554),
11 (n = 553), 13 (n = 508), 15 (n = 517), 17 (n = 457), and 19
(n = 417) years.

The
intervention reduced dietary intake of saturated fat (mean difference
in daily percentage of total energy intake: −2.1 [95% CI −1.9 to −2.3])
and increased intake of polyunsaturated fat (0.6 [0.5-0.7]). The dietary
counseling intervention led to greater serum proportions of
polyunsaturated fatty acids (P < .001), with greater proportions of both circulating omega-3 (P = .02) and omega-6 (P < .001)
fatty acids. The proportion of saturated fatty acids in serum was lower
for both boys and girls in the intervention group (P < .001), whereas the serum proportion of monounsaturated fat was lower for boys in the intervention group only (P < .001).
The intervention also reduced circulating intermediate-density
lipoprotein and low-density lipoprotein lipid concentrations (P < .01).
Dietary intervention effects on nonlipid biomarkers were minor except
from greater concentrations of glutamine in the intervention group.

Repeated
dietary counseling from infancy to early adulthood yielded favorable
effects on multiple circulating fatty acids and lipoprotein subclass
lipids, particularly in boys. These molecular effects substantiate the
beneficial role of saturated fat replacement on the metabolic risk
profile.