How Obesity Induces Overeating?
The reason why you can’t help eating extra servings
You can’t control what your body does to your food. But you can control what you do to your food.
A couple of years back; I could make two meals with a pound of chicken and some rice. I could satiate myself with the food and my tummy didn’t demand more. But as I told you, it was a few years back. Today, I can consume a pound of chicken in a single meal and even more rice. To your perception, my diet has increased; so is my belly now. But how did my tummy made such a remarkable territory? Did it eventually increase in its volume?
The stomach is a muscular structure with good flexibility. Like a balloon expands to its threshold, on filling up with air, our stomach keeps accommodating food to its fullest. And to your knowledge, the human stomach can accommodate and expand its volume up to a gallon, which is roughly 3740 cubic cm. So, the answer is not its capacity. The stomach is distensible and was already big enough for the amount of food I eat. And I have a good memory of being full, with just a half-pound of chicken! How’s that even possible?
Does the answer reside within my stomach? Or is it in my brain? After all, it’s the brain that controls all the voluntary and involuntary actions. Is it the brainy process that made me ingests more than ever?
The connection from the gut to the brain is a complex one. One moment you think something is delicious and feel like devouring it all. And after a few gulps, you’re full. This feel of satiety or fullness obviously is controlled by the brain. But how?
A recent study from researchers at Baylor College of Medicine came up with a chemical signal which gives this feeling to the brain. The hormone named Gastric Inhibitory Polypeptide (GIP) has been known to reveal its activity, to charge the brain with the feeling of satisfaction of food. It is produced in the stomach and is known to involve in maintaining the energy balance in the body.
The experiment was carried in mouse models where the obese mouse produced more of GIP. This excess GIP traveled to the brain, where it works antagonistically to leptin (the satiety hormone). Leptin is the hormone responsible for bringing the feeling of fullness when adequate food has been ingested. But, the excess of GIP in obese individuals blocks the activity of leptin, and the hunger grows voracious. With this, the brain cannot bring the satiety hormone into action, and keep the person from overeating. Thus, obesity and weight gain escalate when the leptin brakes are no more functional.
However, blocking the action of GIP can restore the action of leptin, and can contribute to weight loss.
