the best way to boost your metabolism and burn more fat? Thatís
the holy grail for metabolic researchers and for many
Americans. Orlando, Fla., scientists are at the forefront of
some of the most promising research in the field.
hormone, the "caveman diet" and cooler spaces are
all potentially promising ways to burn more fat, these
scientists say. Long-term, their discoveries could help
reverse the nationís twin epidemics of obesity and diabetes.
Short-term, their findings can help consumers boost metabolism
metabolism determines how many calories he burns, and many
factors affect it, said Dr. Steve Smith, scientific director
for the Florida Hospital-Sanford Burnham Translational
we can increase thermogenesis, or the bodyís ability to burn
calories and stored fat, we could stave off obesity and its
many related ills," Smith said.
metabolism-boosting secret may lie in a hormone the heart
naturally produces, said obesity researcher Sheila Collins, a
professor at the Institute.
peptides, which the heart muscle makes when it perceives high
blood pressure and during exercise, appear to turn on the bodyís
fat-burning mechanisms, Collins said.
peptides also help the body excrete salt, which lowers
elevated blood pressure. Thus, doctors have used a biologic
form to treat patients who have congestive heart failure.
Autopsy studies inadvertently revealed that patients who had
been given this treatment had unusually high levels of
desirable, active type of fat that actually helps burn fat,
brown fat is not like white fat, which is inactive. Everybody
has some brown fat, said Collins, who, like others, is looking
for ways to activate and make more of it.
tested natriuretic peptides in mice and found the peptides
boosted their levels of brown fat.
Collinsí work from the lab to the clinic, Dr. Richard
Pratley, director of the Florida Hospital Diabetes Institute,
in Orlando, and TRI investigator, is looking to see whether it
holds true in humans. He is administering natriuretic peptides
to 40 healthy volunteers: 20 lean and 20 obese. He will then
measure changes in their brown fat.
outcomes look good, long-term infusions to improve metabolism
and manage obesity may not be far away, Pratley said.
can do now: Do anything that increases your heart rate, which
will release these cardiac peptides. "There is no
escaping the fact that we have to exercise," Collins
TRI study underway is comparing the effects on metabolism of a
low-carbohydrate diet and the typical American diet.
have shown that a low-carb diet is more effective than a
low-fat diet for losing weight and lowering insulin, but
"something about eating a low-carb diet causes people to
burn more calories in ways we donít yet understand,"
why, his team will study men who will live in a rigidly
controlled environment at the TRI. For four weeks they will
eat a standard American diet of 50 percent carbohydrates, 15
percent protein and 35 percent fat.
will go through the same drill again, only during the second
four-week period, they will eat a very-low-carbohydrate diet
consisting of 5 percent carbohydrates, 15 percent protein and
80 percent fat. In both diets the calorie content will be
identical and matched to the subjectís caloric needs.
study, funded by the Nutrition Science Initiative, a San
Diego-based nonprofit that aims to understand how nutrition
changes health, is also being conducted at three other centers
across the country. The four centers will collate their
findings, said Smith, who aims to have some answers by
can do now: Cut carbs, and eat more healthy fats and proteins.
In other words, "Go paleo," said Collins.
"Cavemen didnít have many carbs around."
comfort is only human, which is why few of us choose to be
cold or hot if we have a choice.
self-select for comfortable climates," said Smith.
"In environments where our bodies are not trying to get
warmer or cooler, we burn the fewest calories."
more, being cold can wake up brown fat, studies show. A study
published lrecently in PubMed, an online database of the
National Institutes of Health, found that subjects who slept
in a cool room increased their brown fat, compared with those
who slept in rooms that were more moderate or warm.
weíre cold, we activate the brown fat we have," said
Collins. "When we get cold, shivering is the first
response. As people adapt, nonshivering mechanisms take over,
and that involves the activation of brown fat, which goes into
overdrive to keep the body warm."
can do now: Forget the sweater. If you feel a little chill,
try to endure. Try sleeping in a cooler room, swimming in a
cooler pool and taking a cool shower, Collins said.