Childhood Obesity Strongly Linked to Parents’ Genetics
New research suggests that about 35 to 40 percent of a child’s weight predisposition is inherited from mom and dad. In some cases of childhood obesity, the genetic impact may be as high as 55 to 60 percent.
Data collected on 100,000 children and parents from countries including the UK, USA, China, Indonesia, Spain and Mexico. The researchers noted that each child’s BMI was linked to about a 20 percent “contribution” from mom and a similar contribution from dad. The pattern was noted to be pretty consistent across all the countries and was not correlated to the degree of economic development or stage of industrialization, nor the type of economy enjoyed by the country. The data also showed the same 20 percent genetic contribution, irrespective of nutrition and obesity patterns in the countries.
It was obvious to the researchers that obesity seems to “pass on” from parents to child in both developed and developing countries. Transmission patterns were the same in all six countries. What was also interesting is that kids who were thinner seemed to have less genetic linkage to the parents genetics, compared to the more obese children who were “very linked” to the weight genetics of their parents. Children born to obese parents are more likely to be obese. That risk is double compared to the association between parents and thinner children.
One has to wonder, though, if children born to obese parents are given too much food early in life and if they also follow the other lifestyle patterns of their obese parents. Obese parents may model behaviors like overeating and engaging minimally with physical activity and a child from birth, learning those behavior patterns, is likely to be at very high risk of developing obesity due to lifestyle choices. So despite the findings of this study, there is no clear evidence that right from birth these “obese” children were primed for a higher risk of obesity due to genetics as opposed to being due to behavioral habits including overfeeding, unhealthy diets and lack of exercise – behaviors their (obese) parents would likely have perpetuated. Was the genetic risk as high as stated, or was it more of a nurture-linked risk?
Even if the obesity risk was as high as 40 percent, that still leaves a 60 percent opportunity for healthier lifestyle habits to influence genetic risk and lower the predisposition to developing obesity.
The research does serve as a wake-up call to couples planning a child and obstetricians. Intercepting obesity before you decide to have a child can be a positive choice for the parents and the future offspring. If the mother-to-be or both parents are obese, then measures can be taken during the pregnancy to limit the mother’s weight gain while teaching both parents better dietary and exercise habits. In addition to the genetic risk of obesity, the feeding and physical activity behaviors in the early life of the child is likely to dramatically raise the risk of obesity, unless the parents commit to serious and long term lifestyle modification.