The obesity debate, where women have outweighed men—literally—just got fiercer. Men, a new study reveals, can suppress their hunger better than women when presented with their choicest spread of edibles.
Presenting their findings in the 19 January issue of the Proceedings of the National Academies of Science, a team of researchers from the US says the ability of men to suppress thoughts of hunger and eating may perhaps explain the gender differences in rates of obesity.
In two experiments that apparently constituted the first study to understand the voluntary control of hunger, a group of healthy, non-obese men and women fasted for 17 hours. Then they focused on their favourite food and used a technique called “cognitive inhibition” to suppress the desire to eat.
Gene-Jack Wang, a senior medical scientist at Brookhaven National Laboratory, New York, and his colleagues found women’s brains exhibited a lack of response to inhibition. This, they say, is consistent with behavioural studies showing very high scores in women’s tendency to overeat (in response to food stimuli). It could also underlie women’s “lower success in losing weight while dieting when compared with men”, something that applies to all geographies.
According to the latest National Family Health Survey (2004-2008), 75% of Indian women in cities are apple-shaped, while only 58% men are so.
“It’s an interesting study showing that central control of hunger and satiety may be influenced by gender,” says Anoop Misra, director and head, department of diabetes and metabolic diseases, Fortis Group of Hospitals, New Delhi.
In this respect, he says, it is important to note that women in India are increasingly showing higher rates of obesity than men. “Indeed, the obesity- related diseases like syndrome X are higher in women than men in India.”
This could be due to the present finding, says Dr Misra, though it is also well-established that Indian girls and women largely lead a sedentary life. Misra says this new evidence could be useful to fight obesity, as hunger is a central issue and most of the weight loss drugs in the market act on hunger.
Since hunger, or the control of it, now seems to be hard-wired in our brain, is there a way that exercise can change the brain circuitry and suppress hunger to control obesity?
The development of obesity involves multiple brain circuits such as reward, motivation, learning, memory and inhibitory control, so its prevention and treatment should be comprehensive and use a “multimodal approach”, says Wang.
Since exercise generates a number of metabolic, hormonal and neuronal signals that reach the brain, a high level of fitness is associated with decreases in all causes of mortality in both obese individuals and those whose weight is normal, he adds.
“Lifestyle modification (such as education concerning nutrition, aerobic exercise, effective stress reduction) should be initiated in early childhood and ideally, prevention interventions should start during pregnancy,” suggests Wang.
If earlier international studies, including one in the November issue of Preventive Medicine, are to be believed, obese women are also likely to be victims of crime, get sacked and suffer more stress as compared to obese men. Women might construe this as nature’s worst discrimination, but Misra says “science does not favour any gender; it is data that we believe”.
So, now that the neural circuitry of overeating is known, forget about curbing hunger and hit the gym instead!
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