Americans have gotten a little taller and a lot heavier in the past 40 years, and that says a lot about what their future health will be.

For several decades, nations have kept records of the average heights and weights of their citizens.  In an assessment issued last October, the National Center for Health Statistics summarized recent trends in the height and weight of Americans.

On average, American adults are an inch taller and nearly 25 pounds heavier than in 1960.  Men’s average height has increased from 5-foot-8 to 5-foot-9½ while women increased from 5-foot-3 to 5-foot-4.

The average weight gain was disproportionately higher than height gain.  Men went from 166.3 to 191 pounds while women went from 140.2 to164.3 pounds.

The trend is evidenced in children as well.  Ten year-old boys and girls averaged 77.4 pounds in 1963, but 88 pounds in 2002.  Their increases in height were disproportionately smaller.

While weight gain still appears to be increasing in the U.S., increases in height are leveling off, particularly in comparison with the faster growing regions of the world.  For instance, Scandinavians are now about two inches taller than Americans, but 75 years ago, they were shorter.

One analyst, Richard Steckel of Ohio State University, speculated that Americans may not be growing taller as fast as other nations due to better medical care and better overall nutrition in other regions.  In particular, he said, “I wonder if all these calories children are eating are not crowding out micronutrients.  Are we eating junk food instead of fruits and vegetables?  Is our diet imbalanced?”

Another recent study indicates that Steckel is onto something.  Apparently, increases in weight cause people to age faster.  As a corollary, overweight children may mature earlier, allowing growth spurts when they are young but not later as teenagers, when earlier generations typically enjoyed a final spurt of growth.  At the cellular level, today’s overweight teenagers may be too old for that final spurt.

In a study from the online medical journal Lancet, reported June 14 in the Washington Post, researchers produced the first direct evidence that fat accelerates aging.

The Technical Process of Aging

According to Spector, his study is consistent with other recent findings that fat cells may be toxic to the body.

The study found a relationship between weight and telomere length. Telomeres are the caps at the ends of each cell’s chromosomes, the molecules that carry genes. When a cell divides, creating two new cells, the telomeres shorten. In the natural aging process, the telomeres get shorter with each division until the cell can no longer divide. The aging process is the eventual mounting of cells that do not reproduce themselves, thus limiting vitality in various body structures and systems.

In the study’s comparison of women of the same age, lean women had significantly longer telomeres than heavy women, and heavy women had significantly longer telomeres than obese women. A body mass index (BMI) of 30 was considered obese.

Also, the shorter the telomeres, the greater the concentration of the hormone leptin, produced by fat cells, in the blood. Leptin may have a toxic effect on the telomeres in the body’s cells. In the study, researchers also found shorter telomeres associated with greater numbers of cigarettes smoked.

Though the study’s subjects included only adult women, the association of fat with aging almost certainly will hold true for adult men. It may also be an explanation of the reduced height increases in Americans.

By examining cells at the molecular level, scientists determined that the more people weigh, the older their cells appear to be.  The cells of obese people appeared to be an average of nine years older than those of people of normal weight.

The study’s leader, Tim Spector of St. ThomasHospital in London, said, “We’ve known obesity increases your risk of many diseases and of dying early.  What’s novel here is that it seems that fat itself actually accelerates the aging process.  This may not be apparent because these people may not have as many wrinkles.  But underneath, it looks like they are aging at a faster rate.”

With more than two-thirds of Americans overweight and half of them obese, the new evidence indicates a possible epidemic of weight-related, aging illness in the nation’s future.

Despite the growing obesity in American society, Americans generally are living longer than ever.  Of course, the Americans now living these longer lives reached adulthood in the 1930s and 40s, before the abrupt change in diet and exercise of the post WWII era.  The first of the post-war Baby Boomers are now just reaching age 60.  Nevertheless, according to Barry Ramo, a New Mexico cardiologist who writes on health issues for Newsweek, most people today who are 50 have a decent chance of living until they are 90, and younger people should do as well if they take good care of themselves.  Ramo has a four-point guide to living a long, healthy life.

  • Know your numbers.  Weight, blood pressure and cholesterol all matter to your health.  The goals don’t change much as you age.  Set goals for yourself, keep track of these numbers and work toward your goals through diet, exercise and, if necessary, medication.  Losing weight will probably improve your blood pressure and cholesterol.  You’ll have more energy, too.
  • Make a plan.  Exercise won’t happen without a plan.  Start with a reasonable goal (a bit more than you now do) and work toward it.  It may be easier if you find others to join you in your efforts.  Once you begin losing weight, you’ll feel inspired and confident.
  • Face Facts.  Get your doctor involved in your planning and implementation, get regular examinations and don’t worry that health problems may be discovered.  Too many people “just don’t want to know” what’s wrong, so their problems are not discovered until treatment is costly, painful or ineffective.
  • Make connections.  Active relations with family, friends and “personal passions” or hobbies keep a person’s mind focused and alert.  Keep up your activities and interactions as much as you can.  Stay involved in churches, synagogues and volunteer organizations.  Remember, if you don’t use it, you lose it.