Skipping
Meals May Help, Not Hurt, Health: Study
New findings in mice suggest that skipping the
occasional meal may be good for your health.
A report released Monday found that a diet in
which mice ate only every other day appeared to
protect them more from diabetes and the memory-robbing
Alzheimer's disease than either a low-calorie
diet or eating as much food as they wanted every
day.
"The mice are better off on a diet where
they eat fewer meals ... than when they have continuous
access to food," even if that food is part
of a reduced-calorie diet, study author Dr. Mark
P. Mattson of the National Institute on Aging
in Baltimore, Maryland told Reuters Health.
The findings are published in the early edition
of the Proceedings of the National Academy of
Sciences.
Although the research was conducted in another
species, Mattson said the findings appear to suggest
that, for healthy adult humans, forgoing a meal
now and then may not be such a bad idea, "and
it may be beneficial."
"It may be okay to skip breakfast, for example,"
he said.
However, he cautioned against eating nothing for
an entire day. "I would definitely not suggest
people do exactly what we did in the mouse study,"
Mattson said.
The mice were forced to fast for a day and then
given free reign to gorge on food the next. Consequently,
those who fasted ate as many calories as did mice
given as much food as they wanted every day, the
researcher explained. A third group of mice ate
every day, but consumed 40 percent fewer calories
than the other rodents.
After the mice followed the diet for five months,
the researchers gave them a neurotoxin that selectively
damages nerve cells important for learning and
memory, a pattern typically seen in Alzheimer's
disease.
The researchers found that the toxin damaged fewer
nerve cells in the brains of mice who fasted than
in those who either ate freely or followed the
low-cal diet.
Furthermore, blood tests revealed that mice who
fasted had lower insulin levels than those who
followed the other diets, an indication they also
had a reduced risk of developing diabetes.
Past studies have suggested that substantially
cutting calories increases life span and reduces
the risk of age-related diseases. The fact that
occasional fasting appeared to protect against
Alzheimer's and diabetes slightly better than
a low-calorie diet suggests that people can ward
off the effects of aging without starving themselves,
Mattson noted.
The current findings appear to contradict the
adage that humans and other animals should eat
regularly throughout the day, he added, and suggests
that researchers should take another look at whether
that adage is true.
"There needs to be more studies done in humans,
because it's very unclear whether it's important
or not to eat three meals a day," Mattson
said.
Looking back over human history, it makes sense
that skipping the occasional meal may serve our
bodies well, the researcher explained. Early humans
did not have the luxury of constant access to
food, he said, and many often ate one meal per
day or endured several days of fasting before
they found more food.
The humans that survived long enough to reproduce
were the ones who thrived in this environment,
he noted, and our modern bodies may not be so
different.
By the end of the study, fasting mice weighed
more than those given the low-calorie diet, and
slightly less than mice allowed to eat freely,
Mattson said.
Mattson explained that eating fewer meals may
protect nerve cells by placing them under mild
stress, which helps them become better at responding
to more stress, such as the neurotoxin.
Diabetes stems from problems in glucose metabolism,
and fasting may help mice avoid diabetes by cutting
back on when they receive glucose (in the form
of food), causing their cells to become better
at metabolizing it when the glucose reappears,
Mattson noted.
Proceedings of the National Academy of Sciences
2003;10.1073/pnas.1035720100.
