Keeping today’s children from becoming obese has become a constant battle, using many different strategies. Although monitoring the nutritional value of the food they eat is obviously good, two new studies find that controlling their appetite in the earliest stages of their life may set them up for a healthier weight later on.
“Obesity is a major issue in child health,” Professor Jane Wardle, lead author of one of the studies from the UCL Health Behavior Research Center in London, said in a press release. “Identifying factors that promote or protect against weight gain could help identify targets for obesity intervention and prevention in the future.” Though childhood obesity has begun to plateau, the past 30 years has seen a doubling in child obesity rates, and a tripling in adolescent obesity, according to the Centers for Disease Control and Prevention — about 18 percent of both age groups are now obese. More studies are starting to see that tackling this problem earlier may be the most effective strategy.
Infants' Appetites Linger with Age
Wardle’s study looked at both satiety responsiveness (SR) and food responsiveness (FR) in non-identical same-sex twin babies whose SR, or feeling full, and FR, or seeing food, was different. They then monitored the babies’ growth from 3 months of age until 15 months. As you might expect, the twin that had a lower SR tended to eat even after they became full, and it showed in their weight. On average, they were 1.4 lbs. heavier at 6 months and 2 lbs. heavier at 15 months. These measures were almost exactly the same when it came to the twins who had a higher FR.
“These findings are extremely powerful because we were comparing children of the same age and same sex growing up in the same family in order to reveal the role that appetite plays in infant growth,” Wardle said in the release. “It might make life easy to have a baby with a hearty appetite, but as she grows up, parents may need to be alert for tendencies to be somewhat over-responsive to food cues in the environment, or somewhat unresponsive. This behavior could put her at risk of gaining weight faster than is good for her.”
A Genetic Risk for Big Appetites
The importance of catching these signs could become greater if the child is already genetically predisposed to a large appetite. The second study, also from researchers at the UCL Health Behavior Research Center looked at genetic susceptibility to obesity in over 2,000 10-year-old children born in the UK between 1994 and 1996.
The researchers estimated their risk of obesity through a so-called polygenic obesity risk score (PRS), which looked at how many higher-risk alleles — an alternative version of a gene — there were out of the 28 obesity-related genes. Once they assessed each child’s risk, they compared it to the children’s SR and body mass index (BMI) — their level of body fat. “As expected, we found that children with a higher PRS score were likely to have larger BMI and waist circumference,” Dr. Clare Llewellyn, lead author of this study, said in the release.
Controlling Big Eaters
Notably, both studies found that it was a low satiety that led to heavier weights. They suggested interventions to help kids feel fuller. “For example, children with lower satiety sensitivity could be taught techniques that might improve their fullness signals when eating, such as slowing their eating speed. Another approach might be to provide better advice to parents and children about appropriate portion sizes, limiting access to 'second helpings,' and ensuring tempting treats are out of sight between meals,” Llewellyn said in the release.
This falls in line with other research promoting parental rules and limiting portion size. One study, for example, found that changing the size of dishware that the food is served in could help trick kids into eating less. Children who ate out of larger bowls were more likely to pile on the food and even ask for seconds, subsequently eating more. Another study found that children who got better sleep tended to eat less, too. Taking these steps and others reduces their risk for obesity later in life, as well as developing risk factors for obesity-related disease, such as heart disease and diabetes.
Llewellyn C, Wardle J, Plomin R, et al. Satiety Mechanisms in Genetic Risk of Obesity. JAMA Pediatrics. 2014.
Jaarsveld C, Boniface D, Wardle J, et al. Appetite and Growth: A Longitudinal Sibling Analysis. JAMA Pediatrics. 2014.