10 | APRIL 2016
Following a low-carbohydrate, high-fat diet
for just 8 weeks can lead to rapid weight
gain and health complications, according
to research published inNutrition and
Diabetes(tinyurl.com/z4q2vem).
Lead author, A/Prof Sof Andrikopoulos
ofThe University of Melbourne, says this
type of diet, exempliied in many forms of
the Paleo diet, is not recommended, partic-
ularly for people who are already overweight
and lead sedentary lifestyles.
“Low-carbohydrate, high-fat diets arebecoming more popular, but there is no
scientiic evidence that these diets work. In
fact, if you put an inactive individual on
this type of diet, the chances are that person
will gain weight,” said Andrikopoulos, who
is President of the Australian Diabetes
Society.
The research tested whether high-fat
and low-carbohydrate (LCHF ) foods
would beneit the health of people with pre-
diabetes. The research team took two groups
of overweight mice with pre-diabetes symp-toms and put one group on the LCHF diet.
The control group ate a normal diet.
After 8 weeks, the group on the LCHF
gained more weight, their glucose intoler-
ance worsened and their insulin levels rose.
The paleo diet group gained 15% of their
body weight and their fat mass doubled
from 2% to almost 4%.
“To put that in perspective, for a 100 kg
person, that’s the equivalent of 15 kg in
2 months. That’s extreme weight gain,”
Andrikopoulos said.
“This level of weight gain will increase
blood pressure and increase your risk of
anxiety and depression, and may cause bone
issues and arthritis. For someone who is
already overweight, this diet would only
further increase blood sugar and insulin
levels, and could actually predispose them
to diabetes.
“We are told to eat zero carbs and lots of
fat on the Paleo diet. Our model tried to
mimic that, but we didn’t see any improve-
ments in weight or symptoms. In fact, they
got worse. The bottom line is it’s not good
to eat too much fat.”
Andrikopoulos says the Mediterranean
diet is the best for people with pre-diabetes
or diabetes. “It’s backed by evidence and is
a low reined sugar diet with healthy oils
and fats from ish and extra virgin olive oil,
legumes and protein.”Paleo Diet Increases Weight Gain
Brown fat, which burns energy to produce heat, may also help to keep
blood sugar steady in adults.
Researchers at the Garvan Institute of Medical Research have
found that individuals with more brown fat had smaller fluctuations in
blood sugar. The findings open new avenues for diabetes therapies
that target brown fat.
Unlike white fat, which primarily stores energy, brown fat burns
energy – often in remarkably large amounts. Sitting just above the
collarbone and in the neck, it acts like a heat generator, helping to
keep us warm by burning sugar and fat.
Dr Paul Lee and A/Prof Jerry Greenfield found that blood glucose
levels and heat production by brown fat were closely related, tracking
together over time. Importantly, participants who had larger deposits
of brown fat had less fluctuation in blood glucose – and blood glucose
fell after each peak of brown fat activity surge.
In contrast, brown fat activity rose only in response to an increase
in blood glucose among those with less brown fat, and their glucose
fluctuations were greater. Notably, individuals with no detectablebrown fat had the widest fluctuations in blood glucose.
“Our findings indicate that brown fat might act as a glucose
buffer, lessening the variation in blood glucose and potentially
diminishing metabolic stresses that could increase the risk of
diabetes,” Lee said.
The researchers also observed that brown fat activity rose at dawn.
“We speculate that this early morning temperature boost may have an
evolutionary origin, generating heat and preparing our ancestors for
hunting and gathering in the cold as the day begins,” Lee said.
“The study brings brown fat into the frame for developing diabetes
therapies,” Lee said. “If we can pinpoint what switches brown fat’s
activity on and off during the day, we may identify new targets in
drug design.” However, he added that “it is not the solution to finding
a cure for diabetes, at least not now. A balanced diet and regular
exercise are the cornerstones of healthy metabolism and should not
be forgotten.”
The research has been published in Cell Metabolism
(tinyurl.com/z6gnuxg).Mice on a diet mimicking the paleo diet
gained weight.Credit: The University of MelbourneBrown Fat Keeps Blood Sugar in Check
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