In my video series starting with how to get the
weight loss benefits of a federal without the risks.
I noted how drinking water affects the release of the
adrenal hormone nor adrenaline making it the safest metabolic booster
for weight loss and recommended drinking two cups of cold
water on an empty stomach a few times a day
. Ideally before meals is a form of that negative
calorie preloading. As I discuss in my video evidence
based weight loss. But what about just staying hydrated
in general in a national survey? One of the
weight control practices most associated with successful weight loss was
drink plenty of water, but it was also associated
with unsuccessful attempts at weight loss. It's just one
of the most popular weight loss tips across the board
both in the mainstream media in a common recommendation given
to patients by their physicians. But does it work
? Can we just add water? About a dozen
studies have been published on the matter? And overall
, there does appear to be a weight reducing benefit
to increase water consumption. What's the obvious confounder though
uh confounding factors also known as lurking variables are some
third element that ends up being the true explanation for
a supposed link between two things. Here's a textbook
example, there may be a tight correlation between ice
cream sales and drowning deaths, but that doesn't mean
ice cream causes drowning. A more likely explanation is
that there's a lurking third variable like hot weather,
summertime. That explains why drowning deaths are highest when
ice cream consumption is at its peak. So what
might be a confounding factor that offers an alternate explanation
of why those who drink more tend to lose more
weight. Maybe it's because those who drink more water
tend to drink less soda. So maybe the reason
more water is associated to more weight loss is because
there's the third variable, a confounding variable like less
soda consumption connected to both. And that's the real
cause. The primary reason that the CDC USDA American
Medical Association, American Diabetes Association, American Heart Association
and American Academy of Pediatrics, all recommend drinking water
for weight management is as a replacement of beverages with
calories. Even replacing one sugary beverage or beer with
water per day is associated with a lower incidence of
obesity over time. American Children and adolescents drink so
much soda that replacing all sugary beverages with water could
result in an average reduction of 235 calories a day
. And what about exercise? That's another obvious confounder
candidate after all who drinks lots of water, those
who spend hours working out. So no wonder water
drinkers might be slimmer. A study of dieting overweight
women took both soda and exercise into account and still
however found a benefit associated with increased water consumption over
a year. Those who drink at least a liter
a day of water lost about five more pounds on
average than those who didn't. The researchers were able
to control for physical activity and intake of other beverages
. But what about other foods? It turns out
that those who drink more water also tend to eat
more fruits and vegetables, greens and beans and whole
grains and less total sugar and less fast food.
No wonder they're a healthier weight to control for dietary
factories. The scientific world had to bring out the
big guns. Harvard's big cohort studies that followed the
diets and health of more than 100,000 doctors and nurses
for decades. They were able to control not just
for other beverages and lifestyle factors such as exercise,
smoking, sleeping and TV, watching, but a
wide range of healthy and unhealthy food intakes from fruits
and vegetables to meat and candy consumption. They were
the first to show that increasing water intake per se
was independently and significantly associated with less weight gain over
the long term consumption patterns in these studies were by
self report. Though participants were just asked to fill
out detailed questionnaires about their diet for more of an
objective measure. Researchers directly assess people's hydration status by
assessing their blood and urine concentrations in both adults and
Children. The more hydrated people were, the less
likely they were to be obese, spot checking urine
from nearly 10,000 men and women research found that nearly
half of obese individuals were walking around under hydrated compared
to fewer than one in three individuals who were normal
weight or lighter. Uh, the problem with snapshot
in time studies is you don't know which came first
did under hydration lead to obesity or did obesity lead
to under hydration at a heavier weight. You actually
need more water. The daily water requirements of a
man of average height weighing 210 pounds may actually be
four cups more than the same man at 100 and
60 pounds. And who's more hydrated. Those who
eat more water rich foods like fruits and vegetables.
There's that specter of confounding again. The only way
to prove cause and effect is to put it to
the test in an interventional trial which I'll cover next --> .