"Example isn't another way to teach, it is the only way to teach."
—Albert Einstein

"Your actions are so loud, I can't hear what you're saying."
—Ralph Waldo Emerson

I'd throw myself in front of a train if I thought it would save my son. Almost any parent would. If that's true for you, then the results of a new study from Dartmouth Medical School might change your life, or at least your lifestyle. Researchers there used a toy grocery store to find out which foods preschool children would select when given a range of options. They found that children begin to assimilate and mimic their parents' food choices at a very young age (2!), even before they are able to fully appreciate the implications of these selections.

In one sense, it's not surprising that children's diets are similar to those of their parents, because most children are eating at least some of their meals with their parents. However, researchers found that these similarities are based on food preferences rather than simply on food availability, and that these food preferences are based on children's observation and copying of their parents' eating behaviors. Other factors, such as the child's age, parent's education and the availability of television in the home, were not significant.

An earlier study by some of the same researchers found that children in a play grocery store were more likely to select cigarettes if their parents smoked and more likely to select beer and wine if their parents drank alcohol at least monthly. The researchers wrote, "Children are highly attentive to the use and enjoyment of alcohol and tobacco and have well-established expectations about how alcohol and tobacco fit into social settings. Parental behavior may influence preschool children to view smoking and drinking as appropriate or normative in social situations. Positive expectations developed early in life that link tobacco and alcohol use with social settings may prompt individuals to smoke or drink when they are old enough to find themselves in similar social situations." In short, one of the most powerful ways that we teach our children—for better and for worse—is by our example.

Knowing this can be a strong motivator for changing our own lifestyles. In my work, I have found that many people will do for their kids what they won't do for themselves, even those who believe that changing their lifestyle is harder than jumping in front of a train. If I say to parents, "Consider quitting smoking because it will reduce your risk of getting a stroke, a heart attack or lung cancer," they often reply, "It's not going to happen to me."

But if I say, "You might consider quitting smoking in order to set a good example for your children so they won't start" or "... so they won't have their growth stunted" or "… so they won't get asthma from breathing your smoke," then they're often more likely to give upcigarettes. One of the most effective anti-smoking strategies has been for schools to educate children about the harmful health consequences of smoking, causing many of them to go home and say, "Mommy, Daddy, please don't smoke. I love you so much, and I don't want you to die."

We can view our choices in diet and lifestyle as austere sacrifice and deprivation—I can't eat this food or enjoy this indulgence—but it is so much more effective and sustainable to reframe our choices as good examples for our kids that are acts of love. For example, I'm not one of those people who love to exercise, even though I often write about its benefits. It takes effort for me to motivate myself to work out on a regular basis. What motivates me to do so is love for my wife and son: I want to live a long, healthy and happy life with my true love, Anne; I want to be around to watch my son (and future children) grow up and to support them; I want to see them graduate, fall in love and dance at their weddings; and I want to remain healthy enough to play vigorously with them.

Sacrifice is not sustainable. Love is.