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JANUARY 1 2009
AMERICANWAY
do andmuscle helps to burn calories, says
Gidus, alsoanutrition coachat theHuman
Performance Institute inOrlando, Florida.
Musclemass is so important that it explains
another fact:Metabolism slowswithage.
Onceyou reachyourmid-30s,Dr.Mitch-
ell says, yourmusclemass starts “very slow-
lydriftingdown.”Specificsvary, but the rule
of thumb is that people lose one percent of
leanmusclemass foreveryyearpastage40,
adecline thataccelerates toabout threeper-
cent annuallybyone’smid-50s, he says.
Strength-building exercises can some-
what offset that muscle loss, but they like-
ly won’t forestall it entirely, says Charles
Burant, PhD,MD, director of theUniversi-
ty ofMichigan’sMetabolomics andObesity
Center. “Even super athletes can’t do it.”
Prepared to give up? Not so fast. When
combined with calorie control, retaining
muscle can enable you to achieve better
long-term weight loss, Dr. Mitchell says.
“Muscle makes you a better butter burner
—period.”
Here are some other strategies that cli-
nicians and researchers are studying, and
debating, as theydelve further into theme-
chanics ofmetabolism
SLEEP:
If you’reprone tohitting the snooze
button, consider that some recent stud-
ies have linked sleep loss withweight gain.
Women who failed to sleep more than six
hours nightly were 12 percent more likely
to gain 33 pounds than those who slept
seven or eight hours, according to a 2006
study in the
AmericanJournal of Epidemi-
ology
. The researchers, who tracked nearly
70,000women for 16 years, found an even
higher risk, 32percent, when average sleep
maxed out at five hours. One theory is that
sleep deprivation affects the production of
leptin, an appetite-suppressing hormone,
Dr.Mitchell says.
EATING TIMETABLE:
You’ve heard this
advice before. Eat breakfast to jump-start
yourmorningmetabolism. Andbreak your
daily food consumption into smaller and
more frequent meals and snacks. Skipping
meals is particularly bad, Gidus says, be-
cause it encourages your body to shift into
protectivemode, storing calories as fat. Dr.
Burant is less convinced of that, though.
Smaller meals may blunt hunger, but re-
searchhasn’t shownany evidence thatmeal
schedulingmakes a huge metabolic differ-
ence. A calorie is a calorie, he says. “I don’t
think your body, in general, really cares
when you eat.”
METABOLIC PROFILING:
Numerous diet
books and related products relay various
theories regarding the body’s ability tome-
tabolizecertainfoods,mostnotablycarbohy-
drates andproteins. Proponentsof profiling
typicallymaintain thatsomepeoplerespond
better toprotein and thus can achievemore
energyanddietsuccessonlow-carbohydrate,
high-protein diets, while those classified as
carb types should eat ahigherpercentageof
healthy carbohydrates. Dr. Mitchell doesn’t
subscribe to any particular diet, but he sug-
gests talkingwith your doctor about getting
some baseline tests, including for blood
sugar and cholesterol, if you’re struggling to
loseweight. Some people, for example,may
haveelevatedbloodsugar—albeitnot to the
point of being diabetic— and thusmay be
moreprone toelevated insulin levels in their
body, which promote weight gain. Not sur-
prisingly, there’sdisagreement. Such screen-
ing tests can indicate your long-term riskof
heartdiseaseandother chronic illnessesbut
have “nothing todowithwhetheryou’reable
to lose weight or not,” says Samuel Klein,
MD, director of the Center forHumanNu-
trition at Washington University School of
Medicine inSt. Louis.
THYROID CHECK:
Consider getting your
thyroid checked if you’re sticking to your
diet and exercise regimen (really and tru-
ly) and your weight loss is slim to nil, Dr.
Mitchell recommends. The thyroid gland,
located in thebaseof theneck,helps tocon-
trolmetabolism. Soanunderactive thyroid,
which is farmore likely inwomen, can sab-
otage yourbestweight-loss efforts.
EVEN IF YOU’RE
not hitting the gym, you
can boost your metabolism over the long
haul, Dr. Mitchell says. Bolster your daily
activity in seemingly small ways: Take up
gardening, walk to your child’s bus stop,
straighten up the house, and park several
rows back. Peoplehave strayed too far from
their hunter-and-gatherer heritage. “We’ve
systematically worked physical activity out
of ourdaily routine,” he says.
Somepeople, though,maybeprewired to
expend energy without even realizing it. A
research team at theMayo Clinic has been
studying what they call NEAT, short for
non-exerciseactivity thermogenesis. (Think
of that friendwho can’t linger over a cupof
coffee.) In a pilot study, researchers found
that unlike lean individuals, people with
mildobesity spentmore than twohours sit-
tingdaily. Byadopting theNEATbehaviors
of their lean counterparts, they could burn
350more calories aday.
For Sam Zaman, changing his meal
habits became the cornerstone of the diet
he launched in January 2008. Weighing
in at 293 pounds, the 28-year-old real es-
tate appraiser typically skipped breakfast,
worked through lunch, andoverindulgedat
dinner and beyond. Now Zaman preplans
meals and packs snacks so he can eat fre-
quently, andhe strives to consumenomore
than 1,400 calories a day. He hits the gym
at least five days aweek, splitting an hour-
long workout between cardiovascular ex-
ercise and weight lifting. And he typically
gets seven-plus hours of sleep, rather than
watching television into theweehourswith
a snack nearby. In short, he’s a metabolic
enthusiast.
“That’swhat I really attributemy success
to — understanding how the body works
Womenwho failed to sleepmore than
six hours nightlywere 12percent
more likely to gain 33pounds than
thosewho slept seven or eight hours.
