Obese fathers may create problems for their daughters.
A new study published in Scientific Reports has found that obese men undergo certain DNA changes because of their weight that can change the DNA of their sperm, and thus actually lead their daughters to become more vulnerable to breast cancer.
This happens after an obese father's DNA increases the weight in a child's mammary glands, which are known to develop breast cancer.
"This study provides evidence that a father's body weight at the time of conception affects their daughter's body weight both at birth and in childhood - as well as their risk of breast cancer later in life," the study's lead author Dr. Sonia de Assis said in a statement on the study. "Those alterations in sperm may have consequences for next generation cancer risk."
To find this, researchers analyzed four different male mice and their female offspring. All the male mice were overweight or on a standard mouse diet. Once the mice gave birth to their offspring, the researchers looked at the weight of the female mice and found that they had an increased risk of breast cancer.
"Of course our study was done in mice, but it recapitulates recent findings in humans which show that obese men have significant epigenetic alterations in their sperm compared to lean men," Assis said. "Our animal study suggests that those epigenetic alterations in sperm may have consequences for next generation cancer risk."
For now, the researchers recommend that parents keep a balanced and healthy diet that will free their children of potential genetic harm.
"Until we know about this association in men, we should stick to what we all know is good advice," de Assis said. "Women - and men - should eat a balanced diet, keep a healthy body weight and lifestyle not only for their own benefit but also to give their offspring the best chances of being healthy."
This isn't the first time a man's weight has been linked to creating dangers for children. As I wrote in 2015, a study published by Fertility and Sterility found that overweight men are more likely to have sons (likely because overweight men carry more Y-chromosomes, according to the researchers). But a separate study published at the University of South Wales found that obese children usually come from obese fathers. The study found this by looking at overweight grandsons, who were more likely to have overweight grandfathers than thin children were to have thin grandfathers.
Actual men weren't interviewed for the study, but the researchers linked the weight gain to a number of factors.
"The men were now busy with babies, so they didn't have time to themselves. Maybe the dads are on the night shift and wake up with an insane craving for Doritos," Rosin wrote. "Maybe they're too tired to wear anything but sweatpants, so why bother? Maybe they're temporarily off the dating market, so why bother? Maybe we don't need a whole lot of explanation for why an infinitely demanding little being is incompatible with maintaining your fitness routine."
Researchers suggest that physicians and pediatricians that dads visit with their baby also talk to men about fixing their weight issues.
But there are real ways for dads to lose weight, even without time, sleep or equipment to do so. The Post Game, a sports news website, interviewed Jon Finkel, author of "The Dadvantage" in 2010, and Finkel had some ideas about how to stay in shape. He went through some weight gain once he had a child, mostly because he and his wife couldn't make healthy meals due to the lack of sleep. He also didn't exercise much, slowly losing his shape and fitness.
He suggests that new dads look at their schedule and identify where they have time to fit in a run or some push-ups. It's important for these dads to make that small routine into a habit.
Dads should also watch how many calories they consume, and try their best to drink just water throughout the week.
And then there's a more simple way to stay fit - one that can help you keep your child closer.
"For the new dad, every time you put your child in her removable car seat, do a set of 10-15 curls, nice and easy with each arm," Finkel said. "Car seat curls are great because the weight automatically gets heavier as your child gets bigger. By the time your child is too big for the car seat, you'll have arms like Popeye."