Wednesday, February 20, 2013

The FAT In You

This is the third of four blog entries designed around educating my readers on the latest knowledge on nutrition and obesity.  Up to this point we have discussed my own personal problems with weight gain as well as the causes of weight gain (SUGAR).  In this article we will look a little deeper into the associated problems with weight gain and how they affect all of us.
Why is all this sugar stuff important to me?  Well, because I am a dad to a beautiful boy and soon another child as well.  I care quite a bit about his future.  I was alarmed to find out that nutritionist now expect that my son’s generation is not projected to outlive my own (their life expectancy is less).  That’s sad and unprecedented in modern times.  At least his generation can feel good that their poor health will vastly improve the fiscal solvency of social security and medicare for their own children’s generation.  For those that haven't read the previous articles please check out:  Part 1:  The FAT In Me and Part 2:  The FAT In Sugar before following along while we take a closer look at some more of the science behind obesity.

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When nutritionists talk about hormones they aren't talking about estrogen.  They are talking about insulin, leptin, ghrelin, and cortisol.  Lets take a closer look:

INSULIN –  This is the mother of all dietary hormones.  Insulin is released from the pancreas in response to blood sugar levels.  Insulin has one job. It allows for the uptake of glucose from the blood stream into the tissues where it can either be burned or converted to fat. 


As Americans have slowly increased their sugar intake, their release of insulin has also increased leading to higher insulin levels.  The tissues of the body respond to higher insulin levels by increasing insulin resistance because they don’t need or want the extra sugar but the pancreas is a stubborn organ and it really wants to get it out of the blood stream.  Increased insulin resistance is the hallmark of Type II diabetes.  The pancreas senses the increased resistance and it continues to push out more and more insulin until it essentially burns out.  This state is known as insulin dependent diabetes.

LEPTIN – Leptin is released from fat after eating and signals the brain that you are full.  The fatter you are the more leptin you produce.  In theory this should make fat people eat less, however leptin is blocked from signaling your brain by insulin.  So if you circulating insulin levels are high (as they are in most obese people) then leptin can’t do its job.

GHRELIN – Ghrelin rises when we are hungry and goes down after we have fed.  Interestingly obese people have lower levels which would make one think that they are hormonally “less hungry” however that may not be how ghrelin really affects weight, because ghrelin is also involved in our reward system.   It causes dopamine to be released in the reward area of our brain which is what drives the sensation of pleasure.  The good feelings you have after drinking alcohol, smoking tobacco, having sex, and yes, eating sugar, are all due to dopamine and ghrelin helps that out.  This system is blunted in the obese so they actually get less reward for the same pleasurable stimulus!  That’s right, thin people enjoy their “addictions” more than fat people do.  (that just makes me angry)

Incidentally, this dopamine pathway likely helps explain why buproprion (a common anti-depressant) has been shown to be weight neutral to actually weight negative.  It works by prolonging the exposure of dopamine in your brain.

CORTISOL – Cortisol and stress are best buddies.  When stress goes up, cortisol goes up with it.  When cortisol levels rise in most people, their response is to eat.   And they preferentially crave fat and sugar.  We are not sure exactly why this is, but scientist theorize that this may be the natural reaction of our body to early forms of stress (starvation/illness).  It stands to reason that if the body suspected metabolic stress it would do what it could to prepare for it by gathering resources (fat) for the future.

At least a few times since starting my knowledge quest on nutrition I have had people say to me “but fructose is fruit sugar, its natural”.  This statement has two bits of faulty logic.  1)  The belief that natural is healthy.  There are lots of things in nature that will kill you.  Being naturally occurring has nothing to do with being healthy for you.  Cocaine, arsenic, and tobacco are all naturally occurring and pretty bad for you.   2)  The belief that all fructose is equivalent.  In the liver, fructose is fructose, enough said.   However how it gets there is vastly different.  Almost all naturally occurring fructose is conveniently packaged in nature with a whole lot of FIBER.  Fiber speeds up transit in the gut which leads to less absorption of fructose as well as stimulating an earlier satiety signal to the brain which helps you to stop eating.  Added sugar, fruit juices, and HFCS are rarely packaged by companies with fiber.  This is because soluble fiber attracts moisture and reduces the shelf life of products while insoluble fibers add bulk (weight) to an object without improving taste (cost more to produce without increasing sales).

The scary part about all of this knowledge is that we may already be genetically programmed to be fat.  We are born with all the fat cells we will ever have.  How big they become is largely dependent on our diet but the total number is decided while we are in the womb.  Insulin is what causes the production of fat cells in the fetus.  So if mom had higher base levels of insulin from years of excess sugar consumption then baby is more likely to have more fat cells at birth!  We know this is true because mom’s with gestational diabetes have much heavier babies on average.  We also know that the birth weights of today’s children are much higher than past generations and this is largely attributed to larger weight gains in pregnancy and higher circulating levels of insulin! Depressing isn't it.  Well it gets worse.  For most of the 60’s, 70’s, and 80’s we had a huge decrease in breastfeeding and huge increase in formula feeding of babies.  Some mom’s don’t have a choice between breast or formula, but a lot do.  A lot choose formula.  Well guess what.  A 100ml serving of liquid formula has between 11-12 grams of sugar.  The same size serving of breast milk is 7-7.5 grams!  We are training our babies to crave sweeter substances right from birth.  

In the last article I mentioned that sugar and fructose in particular can lead to a lot of bad things.  We already talked about diabetes and obesity but ponder these as well:
BLOOD PRESSURE & ERECTILE DYSFUNCTION – Fructose breakdown requires nitrous oxide (NO) utilization.  NO is our natural dilator of blood vessels.  With less around we have more vasoconstriction leading to higher blood pressure.  NO is also needed to achieve and maintain an erection (Viagra works by helping NO bind to another substance).  Less NO means less erection.
HIGH CHOLESTEROL – Fructose breakdown also produces VLDL, the worst kind of LDL or “bad cholesterol”
GOUT – Fructose breakdown also produces uric acid which will form gout crystals if levels get to high
POLYCYSTIC OVARIAN SYNDROM & INFERTILITY – increased insulin leads to increased body fat which leads to PCOS in women.   PCOS patients have deregulation of their hormone axis leading to infertility.  PCOS patients are sometimes treated by giving them a diabetes drug (metformin) which actually makes your tissues more sensitive to insulin and thus potentially decreases your circulating insulin levels!
ALZHEIMER'S - And just to upset my older readers I thought I would point out this article, which showed a tendency toward higher rates of Alzheimer’s in those with carbohydrate heavy diets.  

My latest writings have been almost solely focused on nutritional changes, and in particular sugar reduction.  I do not want people however to ignore the benefits of exercise.   Exercise does burn calories.  Intense exercise may not burn as much as I previously thought when compared with light exercise but it definitely does burn calories and a whole lot more than no activity at all.  You can estimates calories burned per mile of running (0.75 x weight) versus walking (0.53 x weight) and clearly see a difference.   Exercise has other added benefits as well.  Exercise improves skeletal muscle insulin sensitivity (also what the diabetic drug metformin does) which allows your body to produce less insulin to produce the same effect.  Less insulin is a good thing.  Exercise reduces stress which leads to lower cortisol production which reduces both blood pressure and appetite.  Finally, exercise increases your bodies metabolic pathways (TCA cycle runs faster) which increases liver insulin sensitivity and decreases the conversion of fructose to fat!  So please, don’t stop exercising!
Hopefully by the start of next week I will have finished part four where I will discuss hidden sugars, diet tips, the diet I recommend, and even some sample menus in the final installment:  The FAT Challenge.  Until then consider buying one of these two books.

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