关注了下健康方面的文章
2010-01-03 00:13阅读：
关于食补，呵呵。（from USNEWS website）
If your mental image of an older person is someone frail and thin,
it may be time for an update. For the generation currently moving
through middle age and beyond, a new concern is, well, growing:
obesity. 'We're already seeing a large number of obese elderly, and
if we don't do something, that figure is sure to rise,' laments
David Kessler, former commissioner of the Food and Drug
Administration and author of
The End of Overeating.
Government figures show that Americans in their 60s today are about
10 pounds heavier than their counterparts of just a decade ago. And
an even more worrisome bulge is coming: A typical woman in her 40s
now weighs 168 pounds, versus 143 pounds in the 1960s. 'People used
to start midlife [at a lower weight] and then lose weight when they
got into their 50s, but that doesn't happen as much anymore,'
Kessler says.
If you're entering that danger zone now,
be aware that it's not going to get any easier to lose weight,
because people need fewer calories as they age. Blame slowing
metabolism and the body's tendency starting in midlife to lose
muscle mass—a process known as sarcopenia—and gain fat, especially
around the abdomen. (Fat burns fewer calories than does muscle.)
'All that conspires to make it harder for people to maintain the
same body weight when they eat their usual diets,' says Alice H.
Lichtenstein, director of the Cardiovascular Nutrition Laboratory
at Tufts University. 'People have fewer discretionary calories to
play with, so they need to make better food choices.'
Why do those choices matter? First, carrying an extra 20 or 30
pounds with you into old age doesn't bode well for attempts to head
off the myriad diseases that strike in midlife and later and are
linked to weight—including diabetes, arthritis, heart disease, and
some forms of cancer. (It's probably not a coincidence that one
recent study finds that people in their 60s have more disabilities
than in years past.)
But paying attention to what you eat isn't only about controlling
weight; the need for some vitamins and minerals increases with age.
One is calcium, necessary to protect bones. Another is B12, since
some older adults make less of the stomach acid required to absorb
the vitamin. More vitamin D also is required. 'The skin gets less
efficient at converting sunlight into this vitamin, so more is
needed from other sources,' Lichtenstein says. Fewer than 7 percent
of Americans between 50 and 70 get enough vitamin D from the foods
they eat, and fewer than 26 percent get enough calcium.
Staying lean and eating right are both crucial for maintaining
health through the years. (Kessler recalls a fellow researcher at
Yale who, upon realizing the panoply of diseases linked to body
weight, promptly lost 30 pounds.) If weight is a problem, it is
especially important to cut back on the processed foods that
combine sugar and fat. Studies with rats indicate that when the two
are added to chow, animals can't easily stop eating, says Kessler.
This happens in humans, too, he says, and food manufacturers have
taken note and added sugar and fat to many products. So what should
people eat? A healthful diet at midlife is the same as for younger
adults—it's just that the stakes may be higher. The focus should be
on fruit, vegetables, whole grains, low- and nonfat dairy, legumes,
lean meats, and fish. For someone whose current diet is far from
this ideal, Lichtenstein suggests starting small: Swap dark green
lettuce for iceberg, load more veggies on the dinner plate, eat
more skinless chicken or beans in place of hamburger. And exercise.
Walking briskly for at least 30 minutes every day makes it easier
to get away with the occasional cookie. With some further
fine-tuning of that basic healthful eating plan, you can greatly
improve your odds of staving off the major barriers to a vital old
age:
Bone loss. No nutrient can stop bones from losing
mass over time, but consuming sufficient calcium and vitamin D can
slow the deterioration, says Felicia Cosman, an osteoporosis
specialist at Helen Hayes Hospital in West Haverstraw, N.Y., and
clinical director of the National Osteoporosis Foundation. Once a
person reaches age 50, calcium requirements jump to 1,200 mg per
day (from 1,000 mg). Cosman recommends adding up the number of
dairy and highly calcium-fortified products (such as juice and
cereal) eaten in a typical day and multiplying that by the 300 mg
each likely supplies. Add another 200 to 300 mg for the combined
trace amounts in leafy green vegetables, nuts, and other sources.
Then get the remainder in a supplement. By midlife, adults also
need at least 800 to 1,000 IU of vitamin D to help the body absorb
calcium and, possibly, prevent other diseases, according to the
NOF. Sources include fatty fish such as salmon (also important for
heart health), egg yolks, and fortified foods, but most people need
to supplement.
