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Posts tagged ‘insulin’

Stress

There is a great book out there called ¨Why zebras don´t get ulcers¨ by Robert M. Sapolsky, that I highly recommend everyone to read. This book describes perfectly what stress is and how our body reacts to it. Thanks to this book and it´s well done research I have learned a little bit more about what stress is and how it can affect us.  And I will try to explain this in the following blog.

First, let´s clear up some simple terms.

  • Stressor- is anything in the outside world that knocks you out of homeostatic balance.
  • Stress response- is how your body reacts to the stressor.

So let´s give an example to clarify things: Imagine you are walking down the street and a lion (stressor) comes out of nowhere and starts chasing you, so you decide, if clever, to run.  The body has to react to mobilize energy, so it raises the heart rate, as well as blood pressure and breathing rate.  Arteries are relaxed to let the diverted blood into your muscles (you are going to have to run), veins get more rigid because this causes the blood to return with more force. The body has to halt expensive building projects (you are going to need all the energy possible), so digestion is inhibited. Growth and reproduction are also affected (who cares about the future, you got to take care of the present), and immunity is also inhibited. The body has to mobilize energy so it secretes 2 hormones (it releases more than 2 but for simplicity reasons): GLUCOCORTICOIDS AND GLUCAGON.  These hormones cause triglycerides (where fat is stored) to be broken down into free fatty acids and glycerol, it also causes glycogen to broken into glucose and protein into amino- acids. So, now you got all these simple forms of ¨energy¨ in your bloodstream, so that you can use them to outrun the lion.

Now, all this is good if the lion chases you one day, but imagine if the damn¨ lion¨ is chasing you everyday of your life. Your heart would have to work more, blood pressure would increase, veins become more rigid, vessels have to work harder so they build a thicker muscle layer, they also have a greater change of  being damaged and inflamed since blood pressure is going up.  And on top of that you got the amino acids, glucose and free fatty acids flowing through your blood, meaning that if you add all that up you got a greater probability of clogging those veins up (atherosclerosis).

Also, insulin, which promotes storage of energy and stimulates protein synthesis, goes down. Because when faced with a stress we don´t want to store energy, we want to mobilize energy. So all those who want to build muscle and are under lots of stress will have a harder time developing muscle. And let´s not forget that mobilizing all this energy is ¨expensive¨, meaning you are using energy and that could lead to ¨chronic fatigue syndrome¨.

Now all this doesn´t mean that if you have stress you are going to get sick,  in fact, some people are stress all their lifes and never get sick, but it does INCREASE your risk of getting a disease that makes you sick. So what do we do about it?  We will talk about that in my next blog, but before I go, I do want to say that if the  ¨stressor¨ is really a lion, RUN,  as fast as you can :).

Hoped you enjoyed it!

References

Sapolsky M R, Why Zebras Don´t Get Ulcers. Third Edition, St.Martins Griffin, New York 1994.

 

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Carbohydrates- part 1

I´m a big fan of carbs and I usually eat quite a lot of them. From bread to pasta, to rice, I love them. Although lately they have been getting a bad rap and most people when losing weight are trying to take them out. Even though different studies have shown that the most important factor in these types of diets is the percentage of proteins you eat. In other words, it really doesn´t matter if you go on a low fat diet or a low carb diet, both of them will be more or less effective if you keep your protein intake high (1-3). But anyway, let´s try to explain carbs in simple way.

Carbs are your body´s preferred and most efficient energy source for intense training. Carbs can be stored in the muscle and in the liver as glycogen. Carbs can be divided into two groups more or less, SIMPLE CARBS AND COMPLEX CARBS:

  • Simple Carbs: consists of a single sugar molecule (monosaccharide) or two molecules linked together (disaccharide)
  1. Monosaccharides: Include fructose, glucose and galactose.
  2. Disaccharide:  Which is formed by a combination of two monosaccharide molecules. So for example sucrose (which is table sugar) is formed by the combination of fructose and glucose. And lactose (dairy sugar) is composed of lactose and glucose.

*Simple  Carbs are digested quickly and cause a rapid rise in blood sugar, but they also cause a rapid fall after. Meaning you eat these and after a while you are again hungry! That is why you should be careful with simple carbs, especially if they are not natural. Now this doesn´t mean you shouldn´t be eating fruits. Fruits have a lot of fiber and this cause that the rise in blood sugar to go more slowly and on top of that fruits have a lot of phytochemicals (lots of healthy things ;).

  • Complex Carbs: Also know as polysaccharides. Most complex carbs contain fibre and they provide sustained energy without the highs and lows you get after eating simple carbs. You can divide the complex carbs into two groups.
  1. Starchy Carbs : Which include potatoes, yams, oats, beans, brown rice, lentils, green peas, corn, pumpkin, whole wheat.
  2. Fibrous Carbs: Which include broccoli, spinach, asparagus, cucumber, tomatoes, cauliflower, brussels sprouts, onions, peppers, mushroom, aubergine, lettuce .

We should try to eat more fibrous carbs because of the fibre. Like I said before, fibrous foods take more time to chew and swallow and they have a low calorie density!!

So to summarize, carbs are not that bad and we SHOULD be eating them. The only thing to watch out for is make sure these carbs are ¨NATURAL¨ and not processed, and when eating carbs remember the word ¨dark¨, meaning, you should be eating ¨dark¨ bread, ¨dark¨ pasta and ¨dark¨ rice. And if you want to lose weight try to switch from starchy carbs to fibrous carbs!!

Hoped you enjoyed it!!

 

References

  1.  Hu T, Mills K, Demanelis K, Eloustaz M, Yancy W, Kelly N T, He J, Bazzano L.  Effects of Low carbohydrated diets versys Low-Fat Diets on Metabolic Risk Factors: A Meta-Analysis of Randomized Controlled Clinical Trials. Am J Epidemiol. 2012 October 1; 176: S44-S54
  2. Loria-Kohen V, Gomez-Candela C, Fernández-Fernández C, Pérez-Torres A, Garcia-Puig J, Bermejo LM. Evaluation of uselfulness of a low calorie diet with or without bread in the treatment of overweight /obesity. Clin Nutr.2012 Aug;31 (4): 455-61.
  3.  Soenen S, Bonomi AG, Lemmens SG, Scholte J, Thisjssen MA, van Berkum F, Westerterp-Plantenga MS. Relatively high-protein or ¨low-carb¨energy-restricted diets for body weight loss and body weight maintenance. Physiol Behav 2012 Oct 10;107(3):374-80.

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