Monday, September 17, 2007
TEASER APPETISER: BIL AND HIS FAT CELLS
by Shiban Ganju
This world has two kinds of people: those who flip from one diet to the other without shedding a pound and those who reach the same goal without trying. I met both of them on last Sunday: my brother in law (BIL), the non-dieting-hedge-fund-manager and his friend, a serial-dieter-hedge-fund-lawyer (HFL). Yes, she assured me, there was actually such a job.
Out of their compassion, they wanted to volunteer for an NGO. We decided to meet at an Indian restaurant in Chicago and discuss this over dinner.
My sermon to BIL on 3QD on sugar free diet had as much effect as a barking dog has on a speeding truck. HFL also had read my last post on BIL’s sugar addiction and was so affected that she had started Atkins, which coaxed her to gorge on fats and loathe all carbohydrates like poison ivy. And this was on her sixth diet.
She arrived for dinner in a loose white T-shirt, which announced in red letters,“ I am on a thirty day diet and have already lost fifteen days.”
Her - the hedge fund lawyer’s (HFL) - current fad made my job easy in this Indian restaurant, where fat was as readily available as sand in Sahara and it stared at me from the menu with names like Butter Chicken, Daal Makhani, Panir Burji. . Sympathizing with their fat cells I ordered the food to meet their metabolism. I thanked Atkins.
Fat cells or adipocytes are the primary storage bins for fat. These cells scatter themselves through out the body but preferentially nest themselves around the waist of a male and hips and thighs of a female, which silhouettes him into an “apple” and her into a “pear.” A woman normally has 20 to 25% fat by weight and a man has 10 to 15 %. Anything more than 30% for women and 20% for men is unhealthy. Waist circumference is an indicator of risk of cardiovascular disease – the upper limit is 40 inches for men and 34 inches for women. Fat cells can increase or decrease in size depending on the accumulation or mobilization of fat. Obese people have overstuffed cells and also carry more adipocytes: 60 to 100 billion in contrast to 30 to 50 billion for non-obese adults.
Fat is a trigyceride - three fatty acids mounted on a scaffold of glycerol. Fatty acids are molecules of carbon and hydrogen strewn together like a chain and glycerol is a kind of alcohol. The metabolism of fatty acids produces carbon bits, which further transform into a molecule called Acetyl Coenzyme-A. Utilization of the cleaved carbon bits and the Coenzyme yields 17 molecules of energy-laden phosphate, which makes fats a highly potent storehouse of energy. An average body stores about 60,000 kilocalories worth in fat cells and another 3000 kilocalories in muscle cells. Some fat (trigyceride) floats in the blood and may sometimes settle inside an accommodating liver.
Fat cells contain an enzyme named ‘hormone sensitive lipase’ (HSL), which under the influence of epinephrine (adrenalin) cleaves fat and releases fatty acids and glycerol into the blood stream. The fatty acids travel to the muscles, which utilize them for energy and glycerol enters liver for metabolism. Epinephrine levels increase during exercise, which stimulates HSL to mobilize fat from adipocytes but obesity blunts the sensitivity of HSL to epinephrine.
Action of epinephrine on fat cells also depends on the kind of receptor sites they carry to lock epinephrine. There are two of them: beta and alpha. Epinephrine can increase breakdown of fat through beta-receptor and inhibit it by acting through alpha-receptor. While fat cells have both the receptors, one may be more abundant and sensitive to epinephrine. Fat cells around abdomen are more sensitive to epinephrine than those around hips and thighs, which means it may be easier to loose fat from abdomen than hips.
Another ubiquitous enzyme – lipoprotein lipase (LPL) – lines all the blood vessels in the body and is also present in liver and fat cells. LPL breaks down the fat attached to cholesterol and proteins floating in the blood and acts as a gatekeeper to regulate the distribution of body fat.
Adipocytes also produce a hormone – leptin, which signals to the brain to regulate hunger. Starving fat cells flood the body with leptin, which stimulates hunger and eating; conversely satiated fat cells produce little leptin, which suppresses hunger. Leptin deficiency results in enormous appetite and massive obesity.
What would decide how much food we would eat at the restaurant? Externalities like the aroma, taste, ambience and company were all conducive to a good appetite. But within each one of us a battle of four hormones raged: ghrelin and cholecystokinin from the gut, insulin from the pancreas and leptin from the fat cells. These hormones worked on the hypothalamus to regulate our eating. When we walked into the restaurant, our ghrelin was high and insulin was low, which made us hungry. When food stretched our stomachs ghrelin level dropped and gut secreted cholecystokinin, creating satiety.
As carbohydrates entered the blood stream from the intestine our pancreas flooded us with insulin, which helped mop up sugar and convert excess into fat. Our willing fat cells readily welcomed the floating fat and in return secreted leptin as a signal of engorged satisfaction. Here we were, four adults believing in free will, yet slaves to our own unwilling hormones.
When we had settled half way into our dinner, we started talking about the voluntary work with an NGO that may engage them. They had considered Green Peace, Oxfam and Human Rights Watch. They had done their homework. They told me their concerns and passions and I enquired about the time they could spare from their busy lives.
I forked a piece of succulent chicken from my plate and deposited it my mouth. Relishing the aroma of cumin and ginger, I suggested, “ Why don’t you work with an NGO on world hunger?”
Did I say earlier that the world has two kinds of people: dieters and non- dieters?
I was wrong. There is the third kind that goes to bed every night – hungry. And the world has over 800 million of them, of which fifty percent live in south Asia, forty percent in Africa and ten percent in the developed world. The World Health Organization has estimated that one third of the world population has over-stuffed fat cells, one third has empty cells and one third are simply starving.
BIL and HFL were stunned at the numbers and were earnest in knowing more. I continued, “Every year 15 million children die of starvation. It is estimated that one in 12 children in the USA go to bed hungry.”
Presently the waiter appeared and asked, “ Would you care for dessert?”
BIL ordered a Mango Kulfi.
“ I guess, since we entered the restaurant, probably 400 people have starved to death.”
HFL asked for a Ras Malai.
“What the world spends on its military for a week could probably prevent starvation deaths for ten years. And about three billion people in the world battle with life daily with less than two dollars a day.”
I was too full and shipped the dessert; I ordered a glass of twenty year old tawny port.
“ Every four seconds some one dies of hunger.”
Posted by Robin Varghese at 10:24 AM | Permalink