When a baby is conceived, the baby inherits the father’s genes via his sperm. These genes that are passed on to the baby have the same genetic code that the father got from his parents. This is according to basic genetic rules, but a new study showed that the father’s health during the conception may change the genes that he passes on to his children.

One good example is obesity. This is said to be a genetic condition, but a new study found that the weight of the father during the baby’s conception may alter the genetic makeup of the DNA that his child inherits. His weight may determine the likelihood of that child growing obese or not.

The study examined the sperm of 10 normal weight men and 10 obese men. There were noticeable differences in the genetic markers found in the obese men and those found in non-obese men’s sperms. The differences mostly lie in the genes that determine the child’s brain development and function, particularly those that regulate one’s appetite.

But it can be argued that these differences could have been naturally found in the obese men’s genes, something that they inherit from their own parents.

This is why the research team conducted a second phase. They studied six obese men who are candidates for bariatric surgery. They donated three sperm samples – the first sample donated one week before the surgery, the second donated a week after, and the third donated a year after the surgery. The research team, led by Dr. Romain Barres and his University of Copenhagen colleagues found over 4,000 genetic markers that were changed in the samples donated a year after the surgery compared to those donated a week before and after the surgery.

However, the specific effect of these genetic alterations in the man’s sperm on the children is still an area that will require more research in the future.

Aside from his weight, stress factors may also affect a man’s sperm, based on how there were observed genetic alterations in the sperm of male rats under stressful conditions.

What the research shows clearly, though, is that the genetic makeup that the father passes on to his children changes depending on his health condition during the process of conception. This means that it is also important to take care of the physical and mental health of the father in as much as the health of the mother is being taken care of during conception and pregnancy.

To the men out there, take better care of yourself. The father’s genes may affect your child more than you think they do.