Sydney : The way our brain has been programmed throughout the ages may be the reason why so many of us find it so hard to lose weight and keep it off, according to a new study.
A common refrain of obese people is that they quickly regain all the weight that they have lost, according to David Muller of Murdoch University and co-author of the study.
In recent trials with sheep, similar in size and body fatness to humans, researchers found that body weight and appetite are controlled from the brain area called the hypothalamus.
“The body does not know what obesity or a healthy body weight is. It just recognises that you have been a certain weight for a number of years, so it assumes it is the appropriate body weight that you want to attain,” said Muller.
So when you shed a few kilos the brain, through its nutrition network, works hard to put the weight back on, which could help explain the effect experienced by some dieters.
Miller, who has been studying feed intake and appetite control for more than a decade, completed his recent sheep trials with Clare Adam at the Rowett Institute in Britain.
He said nutrition pathways were built into our brains from our primal beginning when food scarcity was more common than food abundance.
Thousands of years later, humans and animals still have a strong desire to eat and put on body weight and a very poor evolutionary control of losing weight, according to a report of ScienceNetwork.
“Our research has shown that we can reprogramme our brains to avoid this nutritional memory that governs our appetite drive, by implementing strategies to keep the weight off until the brain can reset itself,” Miller said.
“Obviously sheep have different diets and digestive systems to humans, but that does not matter when it comes to brains. The brain is just looking at post digestive information.”
In the study, groups of thin sheep were fattened and fat sheep were slimmed down over a period of a few months, to reach the same level of body fatness as a third control group. At that point, all the sheep looked the same but their brains revealed them to have very different appetite control.