Anatomy Shared Article Research

This blog exists for the Anatomy students at Tree of Life Christian School. We will be reading various scientific articles, summarizing our research, and then commenting on others' summaries. We hope to broaden our view of the current research surrounding the human body, and to help others see how truly amazing the design of the human body is.

Saturday, March 08, 2008

Watch what you eat!

http://www.sciencenews.org/articles/20050402/bob9.asp

Summary
When you’re hungry, you should eat, right? New studies are showing that things besides the need for food are triggering the drive to eat. In fact, our body depends on a large group of cues to control how much we eat.
There are many factors that control the amount of eating hormones produced along with other eating cues. This is leading the medical community to experiment with new methods of treating obesity.
There are many chemical agents, mostly hormones, which control appetite. But most are secondary main hormones. The most powerful appetite encouraging hormone is ghrelin while the most powerful eating suppressants are insulin and leptin. These are the strongest hormones but when these active chemicals are absent, lesser controls take over but they are less efficient at starting and stopping the desire to eat.
In studies done with rats, rats with no insulin producing cells (similar to untreated diabetes) food intake was still censored but only about half as effectively. When diabetic rats are given a small amount of ghrelin, their amount of food intake increased three fold.
Fat, protein, and sugar are three nutrients that are known to fight the call to eat. Studies show that protein and sugar reduced the ghrelin concentration about 70 %, fat reduced is only 50% and at a much slower pace.
Another unusual find is that ghrelin concentrations increase as people lose weight rapidly, but when weight loss occurs over several months the level of ghrelin doesn’t change. And oddly enough, people that are obese have lower ghrelin levels that people suffering from anorexia nervosa. This led scientist to believe that the reception of hunger and hunger suppressants is muddled in heavy people. A study was done where they gave 20 normal weight people and 20 obese people milkshake meals ranging in calories from 250 to 3,000. The ghrelin concentrations fell in relation to the amount of calories in the normal weight people but in the obese people, the concentration fell about the same after all of them.
A study was also done specifically with sugars that showed although less fructose is required to sweeten something that glucose; it does promote calorie consumption which leads to over eating.
Although it has long been speculated, just recently studies have shown that hunger, or specifically weight, and sleep are linked. In a study, it was shown that leptin, the hormone that deters eating, was 20% lower in normal weight men who had had 9 hours of sleep for a week than it was in normal weight men who had only slept 4 hours a night for a week. During this study, ghrelin was also 28% higher in the sleep deprived individuals. The sleep deprived men increased their food intake by 24%, eating larger portions and selecting high calorie, high carb foods.
All the studies done are leading scientists to be able to treat obesity by blocking ghrelin receptors. These studies “look promising”.
Also the injection of suppressants for appetite may prove to be a good treatment. The final things we learn is that new ground is just being broken in the fact that the two forms of ghrelin, one called the active acylated form and the other believed to be the inactive unacylated form, cancel each other. Who knows where the studies of this multiple personality hormone will lead?
Opinion
I think that it is so interesting to see how something as simple as the bodies drive to survive is so complicated. So much is being done with one hormone, which will affect so many things. I have also learned that sleep is vital, it links itself to the outcomes of so many things. When you ignore sleep, the article made that point that humans are the only animals that willing do that, you reek havoc on almost everything.

3 Comments:

Blogger kati ware said...

It is so remarkable that the seemingly simple feeling of hunger is driven by such complicated hormones. It is interesting how the ghrelin concentrations were so off in obese people. This shows that when your obese the whole body functions differently. Another interesting fact was that sleep affects leptin and ghrelin, causing people with less sleep to eat more to “make up for it”. It will be extremely interesting to seem what forms of medication come from these studies of hunger hormones.

Sunday, March 09, 2008 9:33:00 AM  
Blogger Ashley said...

When you go to a resturant, they always suggest dessert to finish a meal. This article said sigar was effective in curbing hunger and I think that is why we always want to finish our meal with something sweet- to polish off hunger!

Wednesday, March 12, 2008 7:41:00 PM  
Blogger I Love Anatomy said...

I thought this was very interesting because i have never really thought about being hungry. Whenever i am hungry i simly eat to cure that hunger. I never thought that hunger was triggered by hormones. It is also interesting to think that humans are the only species that willingly stays awake. It is kind of funny actually but its true that when you don't get sleep your body starts acting weird until you get your rest.

Friday, March 14, 2008 8:49:00 PM  

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