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"What we see in research studies is that food is more than the sum of its
parts," says Cindy Moore, RD, director of nutrition therapy at The Cleveland
Clinic in Ohio and a former spokeswoman for the American Dietetic Association.
"Foods that haven't been highly processed can have more than one effect in the
body. Low-fat dairy foods are high in calcium and protein, but they also
contain a range of other benefits that we are just beginning to understand in
many cases."
And why not make that easier, she and other weight management
experts say, by using what's easily available to help achieve your goals?
Calcium
A small, but growing body of research has found an association
between calcium intake and long-term weight management.
"It's really remarkable what we're seeing in research on calcium,"
says Moore.
Women with the highest intake of calcium from dairy foods, in
relation to their total daily calorie intake, lost the most weight and body fat
over two years, regardless of exercise, according to a study in the December
2000 Journal of the American College of Nutrition . Although the
recommended calcium level for young women is 1,200-1,500 milligrams (mg) daily,
the study found that the average woman's daily intake of calcium was under 800
mg per day.
"Calcium appears to suppress a highly specific chemical in the vitamin D
group," says Moore. "This chemical promotes the laying down of fat. It also
slows the metabolism of fat. Calcium blocks this chemical, resulting in less
stored fat and greater fat metabolism."
In fact, Moore says, animal studies have shown that sufficient
calcium can even raise your body's core temperature. More fat is burned to keep
your body warmer. But this finding has yet to be confirmed in humans.
"Ideally, three servings of low-fat dairy products would give you
the recommended amount of calcium, which is enough to suppress the
fat-producing chemical," says Moore. "It's always better to get your nutrition
from foods, but calcium supplements have nearly as great an effect."
In addition, the weight lost comes largely from the midsection. Fat
deposits in this are a risk factor for heart disease.
"We don't know for sure exactly how the calcium causes these
changes, but it's consistent across the studies," says Greg Miller, PhD,
director of nutrition and science affairs for the National Dairy Council.
"People who ate more dairy seem to partition energy into lean body mass rather
than into fat storage."
Here are the calcium levels recommended for adults by the USDA:
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Age 9 to 18: 1,300 mg
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Age 19 to 50: 1,000 mg
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Age 51 and over: 1,200 mg
That all sounds good, but what if you're picking out a calcium
supplement? There's calcium carbonate, calcium citrate, coral calcium. There
are dozens to choose from.
"Calcium carbonate or citrate doesn't matter," says Moore. "What's
more important is that the supplement also contains vitamin D. That combination
is what you need to maximize calcium's effects."
Soy
An interesting side note to the larger calcium story is emerging in
research on soy protein and soy isoflavones. An article in the American Journal
of Clinical Nutrition in December 2002 found in soy many of the same
properties that have been seen in calcium. More research in soy's potential
weight-loss properties is ongoing, but it is too early to say whether early
findings will hold up in larger trials.
Water
Sure, your body needs water to metabolize stored fat, among other
functions, so drink lots of it. But the amount of water in your food can also
be important for weight management.
"Drinking water before or during meals has not been shown in
studies to not do much in terms of reducing calorie intake," says Clare
Hassler, MD, director of the Functional Foods for Health Program at the
University of Illinois. "But when people eat foods that have high water
content, they feel fuller longer and consume fewer calories. And this effect is
independent of the food's fiber content."
Most fruits and vegetables are between 80% and 90% water. But there
are some high-protein foods that also contain lots of water. Eggs and fish, for
example, are nearly 70% water. And soup appears to give that fuller feeling far
longer than some denser, more caloric foods.
Fiber
"Most of Americans get only about 10 to 12 grams of fiber a day, and that is
far too little" says Hassler. "The Institute of Medicine recommends getting
between 25-38 grams per day for adults."
Hassler says that low levels of fiber can contribute to a wide
range of chronic health problems and diseases, including certain cancers. And
in terms of weight management, people who get too little fiber are missing out.
"Fiber provides a kind of bulk, which gives us the physiological
feeling of fullness," she says. "It can replace calorie-dense, fatty foods from
the diet."
So what is fiber exactly? It is an indigestible plant product.
Since your body can't digest it, it has no calories. Fruits and vegetables are
some of the best sources of fiber.
"Fiber-rich foods can be an important tool in weight management,"
says Moore.
By John Casey
Reviewed By Kathleen Zelman, MPH, RD.
Published May 9, 2003.
Medically updated July 25, 2007.
SOURCES: Cindy Moore, RD, director of
nutrition therapy, The Cleveland Clinic, Ohio. Clare Hassler, MD, director of
Functional Foods for Health Program, University of Illinois. Greg Miller, PhD,
senior vice president of nutrition and science affairs, Dairy Council. Journal
of the American College of Nutrition , December 2000. USDA web site. American
Journal of Clinical Nutrition , December 2002.
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