“You are what you do, not what you say.”

Translation: Actions speak louder than words.

“Put your oxygen mask on first, before attempting to help others.”

Translation: You help others most effectively by helping yourself first.

“Imitation is the sincerest form of flattery.”

Translation: When your kids follow your good example, that’s the sweetest hug you can get.

No matter how you put it, parents set examples for their children that shape their kids’ lives. Loving, engaged parents nurture secure, generous children. Folks who are physically active encourage children to stay active.

Parents who demonstrate adventurous eating habits have kids who like the taste of veggies. Parents have enormous power to launch children on a healthy, successful trajectory.

PRECONCEPTION AND PRENATAL INFLUENCES

Research has shown that Mom’s and Dad’s health before conception and during pregnancy has a huge influence on their offspring’s health as a child, teen and adult. As we mention in our book “YOU: Having a Baby,” research shows that maternal health is important not just for the immediate health of a fetus, but also for long-term health. In fact, prenatal nutritional deficiency has been linked to development of schizophrenia, autism, cancer and brain dysfunction.

Additional research reinforces just how influential the preconception and prenatal health of Mom is to a child’s future:

>> 12 percent of children born to obese moms experience wheezing at 14 months as opposed to 4 percent of those born to normal-weight women.

>> Women who have Type 2 diabetes are far more likely to have a child who develops obesity, Type 2 diabetes and cardiovascular disease.

>> Women with elevated lousy LDL cholesterol are more likely to develop gestational diabetes, and their offspring are more likely to have elevated LDL and clogged arteries.

Dads don’t get off the hook either. A study in a Brazilian pediatric journal states that a father’s preconception “obesity results in insulin resistance/Type 2 diabetes and increased levels of cortisol in umbilical cord blood, which increases the risk factors for cardiovascular disease” in the child. Other studies back this up.

The bottom line: A recent study in The Lancet says the preconception period “is a key window during which poor maternal and paternal physiology, body composition, metabolism and diet can induce increased risk of chronic disease in offspring — a lifetime legacy and major driver of health burden in the 21st century.”

NEONATE AND INFANT INFLUENCES

A major new study in the journal BMJ has found that Mom’s not-so-great lifestyle choices have an enormous effect on a child’s risk for obesity. And that can lead to depression, heart disease, Type 2 diabetes and some cancers.

When the researchers looked at around 24,000 children of almost 17,000 women, they found that if Mom eats a healthful diet, exercises regularly, keeps a healthy body weight, drinks alcohol in moderation and doesn’t smoke, her children are 75 percent less likely to become obese, compared with moms who don’t adhere to any of those healthy habits.

So if you want your children to enjoy a long and healthy life, then Mom and Dad should do all they can to make sure they do too. Eat smart, take a multivitamin, be active, sleep well, avoid toxins like tobacco and manage stress.

Mehmet Oz, M.D., is host of “The Dr. Oz Show,” and Mike Roizen, M.D., is Chief Wellness Officer and Chair of Wellness Institute at Cleveland Clinic. Email questions to youdocsdaily@sharecare.com.