Longitudinal studies are good, and large samples are good. In this case, the subjects were 1,000 children observed over a span of 21 years. These are two reasons why this particular study is called important by such authorities as Tom Barabowski, Ph.D., Editor-in-Chief of the publication Childhood Obesity, who says it “identified four BMI trajectories through childhood, and the family, home, and neighborhood factors, even from infancy, that differentiated those groups.”
BMI stands for Body Mass Index and represents the person’s weight in kilograms, divided by the square of his or her height in meters. Americans eschew the international standard and use feet, inches, and pounds, but BMI is the measurement convention most commonly used to compare conditions in different countries and between different groups.
The Centers for Disease Control and Prevention webpage says, “BMI can be used to screen for weight categories that may lead to health problems but it is not diagnostic of the body fatness or health of an individual.” To some minds, the BMI measurement should only apply to people between the ages of 18 and 65, but it is commonly used in schools and in research applications.
The object of this six-author study was to investigate “the relation between adult weight status and parameters of BMI growth and home and family predictors of BMI growth.” It reconfirmed what other research has shown, that obesity is a kind of self-perpetuating state, because big kids tend to get bigger, and to get bigger faster.
This is why so much effort is devoted to catching a child’s tendency toward obesity early and acting upon it decisively. You can tell by age 5 who is pretty sure to be an overweight, obese, or extremely obese adult, unless something is done about it. The report says,
As a whole, findings highlight the intricate connections among early BMI, subsequent BMI increase, and acceleration of BMI increase, with all factors forecasting obesity in young adulthood.
One predictive factor is the absence of a father. Because “fathers are uniquely instrumental in involving children in boisterous, stimulating physical play,” they are seen as laying the foundation for motor development and physical activity. However, the lack of a father in the home might be offset by the presence of other children in the environment whose example and participation will stimulate active play.
According to the study, at the beginning,
Infants were recruited from community clinics serving low-to-middle income families (1991–1996). Eligible infants were healthy, singleton, born at term, and weighed ≥3.0 kg at birth. Participants were of mixed European, Spanish, American Indian descent. Children were studied in infancy (6-18 months), at ages 5, 10, and 21 years, and up to three times in adolescence (M ages 14.6, 16.2, and 17.3 years).
The study had a couple of weaknesses, like not including premature and low-birthweight babies, who certainly exist in real life. Some self-reporting was involved, such as in the area of the mothers’ pre-pregnancy weights and heights. Also, Chilean society has its differences from American society, so that has to be taken into account. On the other hand,
The study had several strengths, such as the large sample studied over 20 years, the inclusion of important controls to adjust for pertinent confounders, the repeated assessments of objectively measured BMI, and ratings of several home and parenting characteristics measured at children’s infancy and middle childhood.
The researchers concluded that keeping an eye on BMI increase, and especially on its rate of progress, even before age 5, is paramount. Accelerated weight gain is a red flag that forecasts later obesity struggles. Parents must be urged to limit child confinement and promote physical activity.
Small children need sufficient opportunity for movement and for stimulating experiences. Societal influences play into this, according to the report:
Aspects of children’s built environment, such as living in substandard housing and lack of access to safe, appealing play space, also pose risks for obesity.
Other factors that spell danger are unsupportive home and family conditions, especially those that create stress, like the crucial factors of father absence and maternal depression. Low parental warmth and acceptance were associated with the faster acceleration of BMI increase.
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Source: “Home and Family Environment Related to Development of Obesity: A 21-Year Longitudinal Study,” LiebertPub.com, 01/24/19
Source: “Healthy Weight,” CDC.gov
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