Why Is It Critical That You Lose Your Own Fat before You Get Pregnant
Inheritance could partly be blamed for the obesity epidemic. People become overweight because they inherit it from their parents. But how is obesity inherited? Researchers have focused on genetics in an effort to answer this question. They have identified commonly occurring gene variants in obese people that may explain why some individuals become overweight while others do not.
But Are Genes The Cause Of The Obesity Epidemic?
While genes can be responsible for how much a person weighs, they cannot account for the dramatic rise in obesity that is observed nowadays. This is because the human genetic background “has not changed dramatically enough in such a short period of time to explain this increase in the prevalence of obesity”, says Rob Waterland assistant professor of pediatrics at the USDA Children’s Nutrition Research Center at Baylor College of Medicine.
Waterland is basically saying that the frequency of the “obesity” genes in the human genetic pool is the same today as it was 50 years ago. If no more “fat” genes exist today than some decades ago, how can the obesity epidemic be explained on the basis of inheritance?
Obesity Starts In The Womb
Researchers noticed that, although the genetic factors that determine obesity have not changed, what has really changed is the epigenetic factors. Epigenesis refers to the influence of the environment on the expression of the genetic code. The environment today is different from what it was in the past. Therefore, genes are expressed in a different way as well. The environment of the developing embryo is the womb.
Researchers have suggested that it’s not the genes of the mother that ultimately “transfer” obesity across generations, but rather the environment of the womb. This is what determines the weight, and the fate of the embryo.
Waterland and his team conducted experiments in mice that lead them to these observations. They followed three generations of mice that had the tendency to overeat and become obese. They noticed that when a mom would overeat and become obese her offspring would overeat and become obese, too. Hence, obesity would transfer across generations of mice. Interestingly, the offspring would actually become fatter than its mother. Given that the mice were genetically identical, getting fat could not be attributed to changes in their DNA. Researchers suggested that it is probably the womb of the obese mothers that causes the new generation to become obese.
It is possible that the environment of the womb (epigenetics) triggers obesity in humans, as well. If a mother is obese before and during pregnancy, her fetus will be exposed to an intrauterine environment that may permanently affect its body weight regulatory mechanisms and make it more prone to obesity.
These findings may offer an explanation of the current obesity epidemic in humans. Why are people more obese today than in the past? The answer lies in the womb, not so much in the other factors that have been blamed. Overeating, junk food, stress, less sleep, etc. can make people fat but they cannot directly affect their offspring. A “fat” womb, however, will not only transfer obesity to the next generation it will also amplify it. This is the principle of any “epidemic” concept.
Waterland advises obese women who are planning to become pregnant, telling them: “They should try to attain a healthy body weight before pregnancy in order to minimize the risk of pregnancy complications as well as maximize the health of their baby.