2. Genetics and Prenatal Factors
Health is especially important during early life, as this affects health later on. In fact, a lot can be determined while the fetus is still in the womb (2). The mother’s diet and lifestyle choices matter a great deal, and may influence the baby’s future behaviors and body composition.
Studies show that women who gain excessive weight during pregnancy are more likely to have heavy 3-year-olds (3, 4). On the same note, children who have obese parents and grandparents are much more likely to be obese than kids with normal-weight parents and grandparents (5, 6).
Furthermore, the genes we inherit from our parents may determine our susceptibility to weight gain (7). Although genetics and early life factors are not exclusively responsible for obesity, they do contribute to the problem by predisposing people to weight gain. About 40% of overweight children will continue to be heavy during their teenage years, and 75−80% of obese teenagers will become obese adults (8).
Bottom Line: Genetics, the mother’s weight and family history can all increase the likelihood of childhood and adult obesity.