Certain kinds of food fail to satisfy the appetite.

Ever notice how foods loaded with fat never leave you satisfied, while low fat foods leave you feeling fuller longer?

Fat has more calories than carbohydrates and proteins (nine calories per gram as opposed to four calories per gram), so it’s natural to assume that high fat foods will leave us feeling more satiated than foods that are lower in fat.  Typically this is true, but not for the potato chip snacker or for the Pillsbury plunderer.  Dollars to doughnuts, these snack attackers will tell you it’s not true, as one doughnut, one chip, is never enough (a single Krispy Kreme doughnut has 12 grams of fat).

Several factors play into this dietary conundrum, one of which is whether or not what you’re consuming has any fiber in it.  Fiber plays a huge role in what I like to call “the fullness factor,” as high fiber foods are digested slower, and high fiber foods take up more room in the stomach.

But there’s another factor to consider that researchers have only recently keyed into, and its name is palmitic acid.

Palmitic acid is a saturated fatty acid found primarily in dairy foods like milk, cheese, butter, and milk.  Many of these ingredients are used in the production of bakery items like doughnuts, so it’s no wonder doughnuts never leave us feeing satisfied.

To study palmitic acid’s effects on appetite and brain chemistry, researchers fed a group of rats various kinds of fat.  Some of them were fed palmitic acid, while others were fed oleic acid, which is an unsaturated fatty acid found primarily in vegetable oils like olive oil.  They were fed these oils intravenously.

After three weeks, the researchers found that the rats fed the palmitic acid consistently ate more than the rats fed the oleic acid.

The researchers chalk up this fat find to palmitic acid’s ability to chemically alter the brain.  When palmitic acid is consumed in high enough quantities, it triggers the release of a certain protein that effectively renders leptin and insulin useless.  Leptin and insulin are hormones that help regulate appetite.  Among other functions, they tell the brain when the body feels “full.”

The study was published in the Journal of Clinical Investigation and conducted by scientists from the University of Texas Southwestern Medical Center.

As a natural health advocate— and you, a natural health follower— scarfing on doughnuts and snicker doodles to test the scientists’ findings is not the best of idea.  However, I mention this study because each and every one of us “cheats” now and then, so it’s helpful to understand why certain “cheat” foods leave us feeling full, while others leave us feeling flat or unsatisfied.

Besides the kinds of food we’re eating, we also need to take into consideration how fast we’re eating.  As I wrote in a past Mangano Minute, there’s about a 20 minute delay between our brain and stomach in recognizing whether or not we feel full.  That’s why people who are trying to lose weight are advised to eat slower.  Eating slower not only enables the brain to recognize that fullness factor, but it also helps us enjoy our foods a bit more.  And enjoyment is the second most important thing in our daily dinings, the most important one being nutrition, of course.

Sources:
foodnavigator.com
krispykreme.com

Regardless of age, weightlifting reduces muscle loss

The noted poet Robert Frost once said, “In three words, I can sum up everything I know about life:  It goes on.”

How true.  No matter our condition, no matter how difficult or easy our circumstances are, life continues on.

Perhaps the best illustration of this truism is observing one’s exercise regimen once they reach their thirties and forties.

For example, I’ve been an avid exerciser since I was young, but as I’ve grown older, I’ve noticed how I’m not as quick as I used to be, I’m not the same strapping  young lad that I was in my mid-twenties.

But what’s changed?  I’m still pretty much the same weight. I definitely eat better than I used to eat.  So why are my exercise pursuits floundering instead of flourishing?

Obviously the passage of time and age is the answer to this question, but just what is it about age that forces us to recognize our lifting limits?

Well, researchers believe they may have found the answer to that question, and the answer is written in their blood.

By this I mean that as we age, like our decrease in muscle mass, blood flow efficiency decreases as well.

Researchers affirmed this sad fact of life after testing was done on a group of active twentysomethings and sixtysomethings.  Their blood was tested prior to their having breakfast and then tested again afterward.  Each of them were then given a shot of insulin to see whether or not insulin was used differently in the participants’ bloodstream, suspecting it would be used differently depending on their age.

Just as the good doctors’ suspected, insulin was used differently, and as you may have already guessed, insulin was used more efficiently in the young folks’ bodies.

Insulin is something of a renaissance hormone – it has many roles and many talents.  One of them is in regulating how much glucose the blood feeds to the muscles.  As the researchers found, the twentysomethings had a greater blood flow and insulin response in the muscles observed, while there wasn’t much of a change observed in the older group.

The study is published in the American Journal of Clinical Nutrition and was performed by researchers from the University of Nottingham in England.

So, as we age, do we just have to grin and bear our depleting physiques?  Must we be resigned to the notion that we’re no longer our twentysomething selves?

Yes and no.

Yes, we do have to accept that life goes on and our strength does decrease, but we can slow the aging process though our exercise efforts.

As researchers found in a follow-up study, the older men that weightlifted regularly used insulin more efficiently and saw more muscle growth than those that didn’t lift.  In fact, the insulin response and increased blood flow was on par with the twentysomethings!

The researchers define “regular” as weightlifting three times a week.  That’s exactly my idea of “regular” as well, for I weight train three times a week (though I’ll occasionally miss a session or two due to work constraints).

So there you have it.  Life may go on, but you can make sure it goes slowly through moderate amounts of weight training every week.

Sources:
livescience.com
wisegeek.com