152 Obesity
There is also a literature that explores whether childhood obesity tracks
into adulthood. For example, Funatogawa, Funatogawa and Yano (2008)
explored changes in BMI in over 76,000 women as part of a birth cohort
study with participants born between 1930 and 1999. Overall, the results
showed that overweight decreased between ages 2 and 5, increased between
the ages of 6 and 18, and then decreased in young adults. In addition, they
concluded that an overweight birth cohort in childhood does not neces-
sarily become an overweight birth cohort in adulthood, indicating that
obesity does not always track from childhood into later years. In contrast,
however, Wardle et al. (2006) explored the tracking of obesity between the
ages of 11 and 16 in a London school-based sample. The results showed
that the prevalence was high in this sample at age 11 (almost 25 percent),
and that if children were overweight or obese by age 11, this persisted until
age 16. In a similar vein, Baird et al. (2005) carried out a systematic review
of 10 studies which had explored the links between infant growth (up until
age 2) and subsequent obesity and reported evidence that obesity even at
this young age tracks into later life. Further, Reilly et al. (2005) explored the
role of early-life risk factors in predicting childhood obesity and suggested
that as well as a number of weight measures predicting obesity by age 7
(e.g., birth weight, infant BMI, and catch-up growth), this was also
predicted by parental obesity, time spent watching television and shorter
sleep duration. The link between shorter sleep duration and childhood BMI
has also been shown in a Brazilian adolescent population (Wells et al., 2008).
What Are the Consequences of Obesity?
Obesity is associated with a range of both physical and psychological
problems.
Physical problemsObesity has been associated with cardiovascular disease, diabetes, joint
trauma, back pain, cancer, and hypertension (e.g., Bray, 1986; Chan et al.,
1994; World Health Organization, 1998). The effects of obesity are related
to where the excess weight is carried, with weight stored in the upper body,
particularly in the abdomen, being more detrimental to health than weight
carried on the lower body. It is interesting to note that although men are
more likely than women to store fat on their upper bodies, and are therefore