Whitaker and Dietz59 advanced the intriguing
hypothesis that prenatal overnutrition might affect
lifelong risk of obesity. According to this hypothesis,
maternal obesity increases transfer of nutrients across the
placenta, inducing permanent changes in appetite,
neuroendocrine functioning, or energy metabolism.
Results of observational studies59 show a direct relation
between maternal obesity, birthweight, and obesity later
in life; however, the relative contributions of shared
maternal genes versus intrauterine factors are difficult to
differentiate.59 Findings of studies in animals indicate the
potential long-term consequences of maternal obesity per
se—the offspring of female rats with diet-induced obesity
were heavier than the offspring of rats with the same
genotype but without obesity.60 The implications of these
findings are formidable: the obesity epidemic could
accelerate through successive generations independent of
further genetic or environmental factors. However,
undernutrition at important stages of fetal development
can also induce permanent physiological changes that
result in obesity, as indicated by an analysis of the Dutch
famine cohort.61 For this reason, the nutrition transition,
as described by Popkin,62 could place children in
developing nations at particularly high risk of obesity. In
view of these possibilities, an opportune time to initiate
obesity prevention might be before conception.
Children who were bottle fed seem to be more at risk
of obesity later in childhood than those who were breast
fed.63,64 The explanation for this finding could relate to
permanent physiological changes caused by some
intrinsic factor unique to human milk or to psychological
factors, such as locus of control over feeding rate (baby
versus parent) or taste preference.
During early childhood, BMI normally
decreases until age 5–6 years, then increases
through adolescence. The age at which this
BMI nadir occurs has been termed the
adiposity rebound.65 Several observational
studies66,67 have described an increased risk
for obesity later in life in individuals who
have an early adiposity rebound. However,
the biological importance and predictive
value of this association remains a matter of
debate.68,69
Whitaker and Dietz59 advanced the intriguing
hypothesis that prenatal overnutrition might affect
lifelong risk of obesity. According to this hypothesis,
maternal obesity increases transfer of nutrients across the
placenta, inducing permanent changes in appetite,
neuroendocrine functioning, or energy metabolism.
Results of observational studies59 show a direct relation
between maternal obesity, birthweight, and obesity later
in life; however, the relative contributions of shared
maternal genes versus intrauterine factors are difficult to
differentiate.59 Findings of studies in animals indicate the
potential long-term consequences of maternal obesity per
se—the offspring of female rats with diet-induced obesity
were heavier than the offspring of rats with the same
genotype but without obesity.60 The implications of these
findings are formidable: the obesity epidemic could
accelerate through successive generations independent of
further genetic or environmental factors. However,
undernutrition at important stages of fetal development
can also induce permanent physiological changes that
result in obesity, as indicated by an analysis of the Dutch
famine cohort.61 For this reason, the nutrition transition,
as described by Popkin,62 could place children in
developing nations at particularly high risk of obesity. In
view of these possibilities, an opportune time to initiate
obesity prevention might be before conception.
Children who were bottle fed seem to be more at risk
of obesity later in childhood than those who were breast
fed.63,64 The explanation for this finding could relate to
permanent physiological changes caused by some
intrinsic factor unique to human milk or to psychological
factors, such as locus of control over feeding rate (baby
versus parent) or taste preference.
During early childhood, BMI normally
decreases until age 5–6 years, then increases
through adolescence. The age at which this
BMI nadir occurs has been termed the
adiposity rebound.65 Several observational
studies66,67 have described an increased risk
for obesity later in life in individuals who
have an early adiposity rebound. However,
the biological importance and predictive
value of this association remains a matter of
debate.68,69
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