Weight Control Research
The National Weight
Control Registry has been keeping track of individuals who have lost
a significant amount of weight and are successfully keeping it off.
In 1993 Dr. James Hill of the University of Colorado and Dr. Rena Wing
of the University of Pittsburgh in began collecting information on thousands
of successful individuals. Many have tried different ways to lose and
failed, but with persistence they finally found the methods that do
work.
The average person
in the registry has lost 66 pounds and kept it off for five and a half
years. They set a fine example of what we need to do to control our
weight. About fifty percent lost weight on their own and fifty percent
had professional help. To maintain, most follow a low-fat diet, high
in carbohydrates. Eating breakfast seems to be an important factor in
maintenance.
A full two-thirds
report being overweight as children and 60 percent have a family history
of obesity. Resting metabolism seems to be similar to persons of normal
weight. This suggests that activity level and caloric intake are more
important than hereditary.
To maintain their
weight successfully, participants report monitoring their weight often.
Remaining aware of their weight changes allows them to make corrections
before their weight gets out of control.
Another habit they
have in common is that they tend to keep food records. This keeps them
within their calorie guidelines and helps them limit the number of high
calorie foods they take in. Average caloric intake reported is 1400
calorie, with 24 percent coming from fat.
Lastly, successful
weight control requires physical activity. The most frequently reported
activity by folks in the registry is walking. Successful weight losers
average expending 400 calories a day in activity.
The
"Fidget Factor" in Weight Control
By WIN (Weight Control Information Network)
Why do some people
seem to be able to eat whatever they want and not gain weight? According
to researchers at Mayo Clinic in Rochester, MN, it is because they burn
hundreds of calories throughout the day by fidgeting. This fidget factor,
known as nonexercise activity thermogenesis (NEAT), includes behaviors
such as crossing or uncrossing the legs, bobbing up and down, stretching
or standing up often, maintaining good posture, or just being generally
restless.
In a study of 16
people who were fed 1,000 calories per day in excess of weight-maintenance
requirements for 8 weeks, two-thirds of the increases in total daily
energy expenditure were due to increased NEAT. "When people overeat,
NEAT switches on in some people to 'waste' this excess energy,"
says Michael Jensen, M.D., an endocrinologist and one of the investigators.
"Conversely, the failure to switch this on allows the calories
to be stored as fat."
The researchers
measured three main factors contributing to energy expenditure: basal
metabolic rate (BMR—resting the body), postprandial thermogenesis
(digesting, absorbing, and storing food), and physical activity (sports/fitness
activities and NEAT). Overall findings showed that approximately 33
percent of the 1,000 extra calories consumed were burned by NEAT. Of
the remaining calories, approximately 39 percent were deposited as fat,
4 percent were deposited as other body tissue, 8 percent were burned
by BMR, and 14 percent were due to postprandial thermogenesis. Accelerometers
and blood chemistry tests were used to measure energy expenditure in
the study participants, who were between the ages of 25 and 36, were
nonobese, had sedentary jobs, and did not engage in regular physical
activity. Weight gain in the 16 participants varied from 2 to 16 pounds,
with an average of 10 pounds gained in the 8-week study period. Those
with the greatest increase in NEAT gained the least amount of fat. This
suggests that by activating NEAT, individuals may burn calories that
could help in the battle against obesity.
The study was published
in the January 8, 1999, issue of Science Magazine, which can be found
on the Web at www.sciencemag.org. Top
Weight
Control Information Network
WIN publications are not under copyright restrictions and may be reproduced
Dietary
Calcium and Body Fat: Cause
and Effect
By
WIN (Weight Control Information Network)
As dietary calcium
intake increases, it acts at the cellular level to alter energy metabolism
so that more food energy is burned and less is stored as fat. This is
the conclusion of researchers at the University of Tennessee's Department
of Nutrition who studied the effect of dietary calcium levels in mice.
The mice were genetically engineered to express a human obesity gene
called "agouti" in their fat cells, making them useful models
for the study of diet-induced obesity. The researchers, led by Michael
B. Zemel, Ph.D., director of the University's Nutrition Institute, found
support for their conclusions in data from the third National Health
and Nutrition Examination Survey (NHANES III), which shows an inverse
relationship between calcium and dairy intakes and body fat in adults.
Prior research from the Nutrition Institute shows that the agouti gene
stimulates an increased flow of calcium into fat cells. This in turn
liberates fatty acids and stimulates the activity of fatty acid synthase,
an enzyme key to fat synthesis and storage (see related article on page
1). At the same time, calcium influx inhibits fat breakdown. The researchers
suspected that hormones regulating calcium levels both within and outside
of cells were key to these processes, and that dietary calcium could
influence hormone activity. They went on to test the hypothesis that
a low-calcium diet increases levels of circulating hormones, which in
turn stimulate calcium influx into fat cells and increase fat synthesis
and storage. They speculated that a high calcium diet could suppress
hormonal activity and thereby reduce fat mass.
The researchers placed four groups of mice on low-calcium (0.4 percent),
high-fat, high-sucrose diets for 6 weeks. The basal group maintained
the diet with no changes; a high calcium group received the diet supplemented
with calcium carbonate to increase dietary calcium to 1.2 percent; a
medium dairy group received 25 percent of its protein as non-fat dry
milk with dietary calcium at 1.2 percent; and a high dairy group received
50 percent of its protein from non-fat dry milk with a dietary calcium
level of 2.4 percent. After 6 weeks, the basal diet group experienced
a weight gain of 24 percent. The high calcium group gained about 18
percent; the medium dairy group, 17 percent; and the high dairy group,
less than 15 percent. These differences occurred despite all groups
consuming the same quantity of food.
The researchers concluded that low calcium diets lead to increased fat
storage and higher calcium diets favor increased burning of fat. Dietary
calcium in the form of dairy had an even greater effect on reducing
fat storage than a calcium supplement. The authors propose that calcium
in fat cells "is a logical target for pharmacological and/or nutritional
regulation" of
overweight and obesity. Top
The full report can be found in June 2000 issue of The FASEB Journal
at www.fasebj.org.
Weight
Control Information Network
WIN publications are not under copyright restrictions and may be reproduced
Blueberries
as Brain Food?
The National Institute
on Aging and the US Department of Agriculture funded a study at Tufts
University, where rats were fed a diet, high in certain fruits and vegetables,
for eight weeks. The researchers found that rats fed a blueberry rich
diet performed better on memory tests than those fed a normal diet.
The rats also showed fewer signs of aging in their motor skills such
as balance and coordination.
It is believed
that the high level of antioxidants found in blueberries protect the
brain and other parts of the body from deteriorating. As the body converts
oxygen into energy, it produces by-products called free radicals. Small
amounts of free radicals help the body reduce toxins, but in large amounts
they begin to damage body cells, which is called oxidative stress. Antioxidants
seem to reduce this deterioration and the signs of reduced motor skills
that we relate to aging.
A group of rats
given a strawberry supplement also showed evidence of reduced oxidative
stress in the brain. Blueberry, strawberry and spinach diet supplements
all improved working memory, as compared to the control group.
Besides preventing
free radical damage, it is also thought that plant chemicals may increase
cell membrane fluidity. This allows the much needed nutrients and chemicals
to move easily in and out of cells, improving their effectiveness. Other
studies have shown that diets with lots of fruits and vegetables may
have anti-cancer effects as well.
Eight weeks is
a rather short time to develop noticeable signs of improvement. Could
diet improve memory and motor skills so quickly? Studies on humans are
planned to determine the effectiveness of these fruits and vegetables
in improving memory and preventing the age-related decline of motor
skills. Top
For more information
visit http://www.alzheimers.org/nianews/nianews23.htm
Weight
Control Information Network
WIN publications are not under copyright restrictions and may be reproduced
