For most people, losing weight is extraordinarily hard. You need only take a quick look at this New York Times article to see just how frustrating the process can be—90% of people who lose a significant amount of weight gain it right back. Where did it come from in the first place? The amount of food you eat certainly plays a part, but so does your neighborhood, your mom, and the time of day you choose to eat, among other factors.
A new study from University College London suggests that genetics is also a major factor in childhood obesity. Researchers examined a group of 2,269 children between 8 and 11 years old using a method called Genome-wide Complex Trait Analysis (GCTA) to see if the kids deemed to be more genetically similar also had similar body weight. The result: Genes were responsible for 30% of individual weight differences.
This should come as something of a surprise—scientists have long known that genetics contribute to obesity, but there are only a few genetic variants known to explain differences in body weight. The study indicates that there are many others yet to be discovered.
The researchers explain in their study:
Although the method used in the GCTA analysis cannot be used to predict obesity risk for any one individual because the genetic variants involved are not identified, the results underline the importance of additive genetic effects in the development of adiposity in childhood. This supports the current convention of using parental weight status as a proxy for childhood obesity risk. Targeting children of obese parents for early-life obesity-prevention interventions, given that these children are most at risk, might be a useful direction to take.
By the time teachers, relatives, and other adult figures try to help older obese kids lose weight, it may be too late, in other words. And that’s not just because of genetics—living with obese parents who have less than ideal eating patterns can breed poor lifelong habits for kids. One solution: getting child care providers involved in healthy eating efforts, a la Michelle Obama’s Let’s Move Childcare campaign. Whether more sweeping tactics like Mayor Bloomberg’s ban on large sodas in New York City can make a real difference remains to be seen.