Do you have that friend—the one who can eat endless hot fudge sundaes
and never gain weight? Or do you sometimes feel that even if you worked
out three hours a day and ate nothing but celery sticks, you couldn't
lose weight?
Could it be differences in growth hormones in your bodies?
------------------------------------------------------------------
The primary aim of their study is to uncover what about the person's
biology and metabolism differs to make some prone to gain a lot of
weight and others more resistant.
The inspiration for this project came when Horowitz was conducting a
study on low-carb diets. It was important to that specific research
project that volunteers maintain a steady weight. This worked for most
participants, but there were a few people who seemed to lose weight no
matter how many additional calories were added to their diets.
http://www.physorg.com/news9144.html
Why do some people gain weight when others don't?
Source: University of Michigan
December 16, 2005
Jeff Horowitz, assistant professor of kinesiology, recently received a
five-year, $2.1 million grant from the National Institutes of Health to
look at what may be causing different people to gain or lose weight when
they appear to eat and exercise the same amount.
"When you gain or lose weight, it has to be due to an energy imbalance,"
Horowitz said. Although losing weight for most people is far from
simple, the regulation of body weight boils down to simple math:
calories eaten minus calories burned equals weight gained.
If people gain weight at different rates despite eating the same number
of calories, there must be a difference in how much energy is expended.
For Horowitz’s new study, participants will spend two weeks in the
hospital with their diet and physical activity closely monitored.
Volunteers will get 2,000 calories more than they need each day while
Horowitz’s team studies how quickly they gain weight and body fat.
After two weeks, volunteers will go on a calorie-restricted diet, and
the researchers will look at how quickly the extra weight and body fat
come off.
The primary aim of their study is to uncover what about the person's
biology and metabolism differs to make some prone to gain a lot of
weight and others more resistant.
The inspiration for this project came when Horowitz was conducting a
study on low-carb diets. It was important to that specific research
project that volunteers maintain a steady weight. This worked for most
participants, but there were a few people who seemed to lose weight no
matter how many additional calories were added to their diets.
One of Horowitz’s collaborators, Ariel Barkan, a professor of internal
medicine and of neurosurgery at the U-M Medical School, noted that he’d
seen a similar reaction in a rodent study, with the same diet causing
some to gain much more weight than others, despite similar activity
levels. It turned out that animals with high levels of growth hormone
were resistant to gaining weight.
Horowitz returned to his study data, which included growth hormone
samples from his volunteers, and found that there was a strong
connection between those who had high growth hormone levels and those
who had lost weight.
Growth hormone spikes and falls a few times throughout the day. Those
who lost some weight on the diet that should have kept their weight
stable had higher spikes, not just consistently high hormone levels.
To test the connection, Horowitz will use volunteers with growth hormone
levels on the low side of normal. Some of these participants will
receive a constant level boost of growth hormone during their two weeks
of indulgence, while others will get additional growth hormone following
the body’s usual pattern of daily spikes.
As part of the study, Horowitz will take muscle biopsy samples to
measure muscle protein synthesis, which burns a lot of energy. Horowitz
hypothesizes that one way growth hormone may help make people more
resistant to gaining weight is by increasing the activity of bodily
processes like this that expend a lot of energy throughout the day.
If the researchers see that giving additional growth hormone alters
weight gain, that could mean that it is an effective treatment for
people who struggle with obesity.
The bad news is, there’s a linear decline in growth hormone as we age,
so if Horowitz’s theory is right, this could be one reason we gain
weight as we get older—it’s part of our body chemistry. Gaining weight
reduces growth hormone, too, so you can get caught in a vicious cycle.
The good news is, exercise boosts growth hormone, so those with milder
weight control issues might simply find that enough physical activity to
generate more growth hormone could help manage weight—separate from the
calories the exercise burns.
Horowitz plans to begin screening volunteers this month.
Source: University of Michigan
--
1) Eat Till SATISFIED, Not STUFFED... Atkins repeated 9 times in the book
2) Exercise: It's Non-Negotiable..... Chapter 22 title, Atkins book
3) Don't Diet Without Supplimental Nutrients... Chapter 23 title, Atkins
book
4) A sensible eating plan, and follow it. (Atkins, Self Made or Other)