Scientists have pinpointed exactly why obese people don't
lose much weight when they diet.
Researchers at Sydney's Garvan Institute of Medical Research
have found that a chemical known as the Neuropeptide (NPY),
which stimulates appetite, plays a major role in controlling
whether the body burns or conserves energy.
The study, published in the journal Cell Metabolism, shows
that when the body takes in less energy or is on a diet, high
levels of NPY signal to the body that it's in starvation
mode, and the body subsequently starts storing as much energy
"Evolution provided us with these mechanisms to help us
survive famine," co-author Professor Herbert Herzog told AAP.
"But now we're eating more than we should because food is
always available, so in many cases additional energy is
stored as fat," he said.
"When you try to lose the extra weight, NPY will trigger and
it defeats the purpose of quickly lowering your calorie
Professor Herzog said with obesity being a major epidemic in
the community, researchers have found it challenging to find
ways of tricking the body into losing weight because of NPY.
"Now that we have identified the exact brain circuitry, drugs
can be developed to target and control these types of
neurons," he said.
Professor Herzog said it was important to note that the study
showed that fad diets simply did not work.
"Weight loss needs to be done over a long period of time and
that's what people underestimate," he said.