Some of you may remember the sitcom The Brady Bunch, the wholesome all-American family. When they weren't all gathered around the table eating pork chops and applesauce while gabbing about the triumphs and mishaps of their day, they were riding their bikes or playing ball in the garden. Or the family might be camping together, competing in a sack race – or even just running down the stairs of their double-storey house to answer the phone. The family TV show that aired in South Africa in the late 1970s may not have reflected some of the harsher realities of family life in that era, but it did show we moved around more in those pre-computer, pre-cellphone times.

Today, we wistfully reminisce about how people lived before video games usurped playing ball and fast food replaced meals around the table. We can learn from the way we lived then, including how to eat healthier and lose weight.

The home-cooked advantage
The family dinner is disappearing, plummeting 33% in the past three decades. The result is obvious: "We're eating more calories and getting less exercise than previous generations," says Dr Lawrence Cheskin, director of the Johns Hopkins Weight Management Center in the US. "Supersizing our food is super–sizing us."

Aside from the emotional benefits of sharing a family meal, the real advantage is control – of the quality, ingredients and portions of food. In 1970, 34 % of America's food budget was spent in restaurants. Now it's nearly half. "And restaurant portions have ballooned," says Dr Lisa Young, a professor at New York University and author of The Portion Teller. In her research, Young found restaurant portions were two to eight times that of standard serving sizes.

Eating while driving or watching television has another unhealthy side effect. Distracted, we don't realise how much we're putting in our mouths. At family dinners, when we pause to talk, we eat more slowly, allowing our stomachs time to signal our brains that we're full.

Little moves matter
In addition, so much of what's been designed for our high-tech age keeps us from moving around. We sit for hours at the computer – working, shopping, reading, researching, playing games, even making friends.

Without ever leaving the couch, we can answer the phone, change the channel and send e-mails from our handheld devices. Studies have shown that a large number of kids raised on these gadgets may expend almost no extra physical energy in the course of a day.

But here's how it used to be: we got up to change the channel. We walked to the corner postbox to send a letter. We ran around the garden to play a game. We got up to answer the phone. We went to the library to do research. We made new friends in the park or playing putt-putt. Parents went for a walk after dinner. Kids went outside and just played. And those little expenditures of kilojoules really added up.

Today, kids must be productive and prepare for success. From 1981 to 1997, children's free time dropped by 12 hours a week and unstructured activities by 50 %. "We're so worried about our kids being able to compete that we've created stress for the entire family," says Dr William Doherty, professor of family social science at the University of Minnesota. And, as we know, stress can lead to overeating and obesity – something we never saw in the lives of that Brady gang.
Additional reporting by Lisa Miller Fields