When the U.S. Census Bureau says, “We are developing the new portrait of America,” it is likely that food industry executives look upon this as little more than the latest way the bureau chooses to assert the importance of its work. Yes, it may be right to adopt a ho-hum attitude toward the decennial census undertaken in 2010. Yet, the food industry would be well advised to recognize that the “portrait” may not just illuminate the marketplace in which it operates but also may produce surprises. Often in the past, the wealth of data from this every-ten-year study has re-shaped the industry’s views of itself. Even as marketers have gained new skills designed to minimize shocks from the revelation of such basic data, the likelihood of the unexpected has, if anything, increased.

The past year provides a good example of how the Census Bureau’s findings may be relegated to a lesser position in assessing the factors at work in the food marketplace. Studies of what accounts for 2010 being a disappointing year universally emphasize the recession. It was “the greatest barrier to growing sales and profits,” said the Food Marketing Institute. Identical-store sales decreased an average of 0.82% from the prior year, and aggregate sales rose by what was called “a meager 0.12%.” The F.M.I. naturally centered on “the complex and challenging marketplace,” giving particular attention to fierce price competition.

In surveying retailers, the F.M.I. cited three issues — the economy, competition and healthcare costs. Efforts to build store loyalty proved less effective than in prior years, the survey showed, again, because of the economic downturn and high levels of unemployment. Increased focus went to private label, reflecting the perceived need of retailers to create a differential advantage, the F.M.I. said. These programs in turn were driven primarily by the belief that consumers, concerned about jobs and the economy, respond best to price incentives.

Issued nearly coincident with the F.M.I. survey were new Census Bureau findings on marriage and households that, on careful analysis, may have just as great an impact on shopping as the recession. One probable cause of overlooking such factors is that they have existed for so long. The Census Bureau said the median age at first marriage had risen to 28.2 years for men and 26.1 for women, both up one year or more from the median in 2000. The upward trend in the age at which Americans marry has been in progress since the 1950s, and it is reflected in the parallel fall in share of adults married, down to 54.1% in 2010 from 57.3% a decade earlier. These have a tremendous impact on food buying.

The data on marriage ages and households are alone sufficient to make for a new understanding of how these factors affect the food business. For instance, the percentage of households headed by a married couple who had children under 18 — long regarded as the prime target for the food business — fell to a historic low of 21% in 2010, contrasted with 24% a decade earlier. Of children under 18 years of age, only two-thirds, or 66%, now have two married parents, off from 69% in 2000. The only “increase” in these data was the percentage of children under 18 who lived in a household that included a grandparent, rising to 10% in 2010 from 8% a decade earlier. Of 7.5 million children who lived with a grandparent in 2010, nearly a quarter did not have a parent in the household.

Even this set of specific changes promises significantly new patterns in food — the type wanted, quantities, prices to be paid, and what explains purchases. The 2010 Census promises to reflect not only these important shifts but also an amazing range of additional data. Sure, the recession has dampened food demand, but its power is overshadowed by the way the family is much different from just a decade earlier.