Energy Systems in Your Body

While a calorie is a calorie, the “burning” of calories (aka food) consumed can be very different.

In the human body, there are two separate systems that break down macronutrients to produce energy, and three different energy systems tailored to the type, intensity, and duration of activity.

Energy Currency

To make use of the three different bioenergetic systems, the body uses one predominant molecule to store and transport the energy: adenosine triphosphate (ATP).

Energy is produced when one of the three phosphates from ATP splits off, fueling your movements and warming you up, while also leaving adenosine diphosphate (ADP) and a lone phosphate behind.

ATP ←→  ADP + Phosphate (P) + energy

When you start moving, you begin drawing on your small ATP stores. The three energy systems kick in to help replenish ATP levels and keep you grooving, but your body may prioritize activity of one system depending on the nature of your activity.

Phosphocreatine (PCr) System

The phosphocreatine energy system is prioritized during the first 15 seconds of very high-intensity activity, in the absence of oxygen (anaerobic). This includes activities such as weight lifting, high and long jumps, and the 100-meter dash.

This system exploits the ability of a protein, creatine (Cr), to bind and store phosphate molecules in the form of phosphocreatine (PCr), that can replenish a recently used ATP by providing the phosphate it just split off.

PCr → P + Cr + energy

            ⬇

ADP + P → ATP

This allows for a rapid replenishment of energy currency for a short burst of high-energy output. If you are still exerting lots of energy, your body will be forced to utilize the next system.

Anaerobic Glycolytic System

After the first 10-15 seconds of intensive exercise, and until about 3 minutes, the anaerobic glycolytic system is prioritized, breaking down glucose (carbohydrates) without the presence of oxygen to produce ATP.

The process is relatively inefficient, ‘leaking’ energy as heat, and leaving an undesirable by-product known as lactic acid. This is why you find yourself wiping your brow after sprinting to catch your bus on time.

This system is mainly active during sports events such as the 800-meter sprint, downhill ski racing, and sprints during soccer or hockey games. Still high-intensity activity, but not all out at once.

The final system applies to almost every activity you could think of.

Aerobic Oxidative System

The aerobic oxidative energy system uses the oxygen to help breakdown carbohydrates, then fats, and proteins (as a last resort), to produce ATP. The macronutrients are broken down in a stepwise fashion to efficiently harness the energy and minimize the losses as heat.

This system is active when any activity occurs at an intensity below the threshold of the anaerobic glycolytic system. Daily activities such as walking, jogging, chores around the house, all use this energy system.

Now remember, all systems turn on when activity begins. However, depending on the activity, intensity, and duration, one may be prioritized to better fit your energy needs!

To Sum It Up

The energy currency within the body, ATP, produces energy when one of the three phosphates breaks off. ATP replenishment occurs in three different systems within the body depending on the type, intensity, duration of activity.

The Phosphocreatine system uses a protein called creatine that provides phosphates for almost immediate ATP recovery within the first 15 seconds of very high-intensity activity. The anaerobic glycolytic system breaks down glucose inefficiently to recover ATP quickly, usually working between 10 seconds to 3 minutes after activity starts. The aerobic oxidative system uses oxygen to slowly yet efficiently harness energy from all macronutrients and recover ATP levels.

- Lucas Roldos

Disclaimer: The information provided is meant to spread knowledge and induce interest for educational purposes. It is based on limited research. We try to pull the overall message of the literature, but further research may be necessary.  What is done with the information or suggestions is solely the consumers decision. The information provided is not meant to treat or diagnose any medical condition. References are provided for informational purposes only and do not constitute endorsement of any website or other sources.

Reference:

Bean, Anita. (October 2017). The Complete Guide to Sports Nutrition. London: Bloomsbury Sport.

Wells, GD, et al. (September 2009). Bioenergetic Provision of Energy for Muscular Activity. Paediatric Respiratory Reviews.

Other references provided within the text as hyperlinks

Five Fabulous Fatty (Heart and Brain Friendly) Foods

 

Not all fats are created equal.

While you would be wise not to overindulge in deep-fried, bacon-wrapped, cheese-stuffed jalapeño poppers (along with most fare sold at the fair), some fats and oils are good for you. In moderation, they may even help to support your heart and mind.

#1. Olives and olive oil

A staple of the Mediterranean diet, olives have been shown to protect against stroke.  Research has found that diets favoring olive oil for cooking can reduce the risk of stroke by 33% compared to diets that avoid fat[1]. This is because olives and olive oil contain a natural anticoagulant called hydroxytyrosol, which can prevent blood clots from forming. One to two tablespoons of olive oil per day was found to offer the most protective effect. It even blends well in smoothies!  

#2. Walnuts 

As with olives, walnuts contain a stroke-fighting agent called omega-3 fatty acid. Diets high in olive oil supplemented with walnuts reduce the risk of stroke by 40% compared to diets that avoid fat[1]. A small handful of walnuts a day is all you need—in combination or substituted with other varieties of nuts, such as almonds, pecans, or cashews.

#3. Plant sterol-enriched margarine 

Margarine has suffered from negative publicity over the years from its association with trans-fat—a troublesome fat linked to heart disease. Nowadays, there are perfectly healthful forms of margarine on the market, if you know what to look for. Look for the terms “non-hydrogenated” and “no trans fat” on the label, and make sure that it is enriched with plant-sterols. These block cholesterol from entering the body and result in a lowering of cholesterol in the blood (always a good thing for guarding against heart disease)[2]. Try substituting your butter with plant sterol-enriched margarine, while limiting it to two tablespoons per day. 

#4 Salmon

            There’s an old saying that goes, “Fish is brain food.” And they were right! Salmon contains extremely high levels of docosahexaenoic acid (DHA), a major building-block of the brain[3].  Eating fish high in DHA—such as salmon or even mackerel—at least twice per week will help prevent long bouts of low blood DHA levels, which is a risk factor in the development of Alzeimer’s dementia[4].

#5 Avocados

Although technically a fruit, avocados contain little in the way of sugar content. Instead, they are rich sources of fat, namely oleic acid (also found in olives), sterols, as well as fiber, which all guard against heart disease and stroke[5]. Moderate consumption (no more than one avocado a day) is unlikely to lead to weight-gain[6]. Avocados are also good sources for vitamin C, vitamin E, vitamin K, niacin, potassium, and folate. Avocados taste great as a spread! 

To conclude, don’t be afraid to add more of the above good fats to your shopping cart. Not only can they help you feel more satisfied and full after a meal (so that you won’t pig out on less healthful sugars and fats later in the day), they are literally essential to a longer and better life.

- Tyler Feeney-

M.Sci (c) in Dietetics

 Disclaimer: The information provided is meant to spread knowledge and induce interest for educational purposes. It is based on limited research. We try to pull the overall message of the literature, but further research may be necessary.  What is done with the information or suggestions is solely the consumers decision. The information provided is not meant to treat or diagnose any medical condition. References are provided for informational purposes only and do not constitute endorsement of any website or other sources.

References

1.      Estruch, R., Ros, E., Salas-Salvadó, J., Covas, M.-I., Corella, D., Arós, F., . . . Martinez-González, M. A. (2013). Primary prevention of cardiovascular disease with a Mediterranean diet. New England Journal of Medicine, 368(14), 1279-1290.

2.      Kendall, C. W., & Jenkins, D. J. (2004). A dietary portfolio: maximal reduction of low-density lipoprotein cholesterol with diet. Current Atherosclerosis Reports, 6(6), 492-498.

3.      The Office of Disease Prevention and Health Promotion: https://health.gov/dietaryguidelines/dga2005/report/html/table_g2_adda2.htm

4.       Kyle, D. J., Schaefer, E., Patton, G., & Beiser, A. (1999). Low serum docosahexaenoic acid is a significant risk factor for Alzheimer’s dementia. Lipids, 34(1), S245-S245.

5.       Wang, L., Bordi, P. L., Fleming, J. A., Hill, A. M., & Kris‐Etherton, P. M. (2015). Effect of a moderate fat diet with and without avocados on lipoprotein particle number, size and subclasses in overweight and obese adults: a randomized, controlled trial. Journal of the American Heart Association, 4(1), e001355.

6.       Pieterse, Z., Jerling, J. C., Oosthuizen, W., Kruger, H. S., Hanekom, S. M., Smuts, C. M., & Schutte, A. E. (2005). Substitution of high monounsaturated fatty acid avocado for mixed dietary fats during an energy-restricted diet: effects on weight loss, serum lipids, fibrinogen, and vascular function. Nutrition, 21(1), 67-75.

My Microbiota Made Me Do It!

This holiday season, you’re going to be able to resist that second piece of apple pie.

Not because you’ve been bolstering your willpower all year (although power to you if you have!), but because you’ll know you’re not the only one craving that sweet, gooey, triangle of deliciousness.

You will know that something else is filling up your craving cup, letting it overflow past one piece of pie. But first, let’s cover some basics.

The Gut-Brain Axis

Do you ever wonder why your stomach may cramp up from swimming in cool water after eating a large amount of food? Your brain slows your digestive system to focus on moving and keeping you warm, cramping up your gut!

The gut-brain axis is a communication system between, you guessed it, your digestive system and your nervous systems.

This communication system is what triggers your cravings of warm apple pie, even on a full stomach: your brain releases appetite stimulants and your gut suddenly opens up room for dessert unlocking that “second stomach”.

However, the gut is not alone. There’s an enormous party of microorganisms that can have influence on this gut-brain axis, and they’re living inside of your gut!

Manipulating Microbiota

The something else driving your cravings is the community of microorganisms living in your gut called your microbiota.

We benefit from them about as much as they benefit from us; microbiota are involved in nutrient metabolism, anti-microbial protection (against disease causing bacteria), immunity, development, and more.

Microbiota Mind Control

The crazy thing is, research suggests that microbiota within the gut seem to have some level of control over appetite, taste perception, and even behavior.

Don’t take this to mean that your gut microbiota are controlling your mind. After all, we have grown up and evolved with them.

Nevertheless, you are still their host, and your microbiota will try and sway you in their favor using hormones, neurochemicals, or any other trick they have up their sleeve.

Your Microbiota likes dessert as well

The microbiota have their own food preferences and will release more reward chemicals than your own body does after you eat something they need. Depending on the microbiota, that could mean cravings for the fatty, sugary, holiday desserts!

The more of one type of microbiota you have in your gut, the stronger that signal is presumed to be. This is partially why obese individuals have a much harder time keeping weight off, and why a varied diet is generally praised as healthy.

Lost In The Masses

Studies have reported a decreased gut microbial diversity for either side of the appetite spectrum, obesity and anorexia nervosa. It may even be associated with depression and anxiety.

With a varied diet of micro and macronutrients, you should be feeding several different kinds of microbiota. The more kinds of microbiota you have in your gut, the more competition each microbial organism encounters.

Imagine you are going out to eat with two of your friends. They are a bit more similar in food taste than you are and inch toward one option, leading you, the odd one out, to follow.

If you were a group of ten friends, your food interest would likely be a bit more varied based on culture, preferences, etc. and the decision would not be so clear. It would be easier to make your own decision over the larger discussion.

In principle, this is how your microbiota would work: even if they have enough resources to try and manipulate you after the competition, no matter what method of manipulation they try on you, any particular signal would likely be lost in the variety of signals, allowing your own signal to dominate.

This holiday season, be conscious of your diet variety to prevent any extra cravings!

To Sum It Up

Microbiota within your gut make use of the gut-brain communication system attempting to manipulate your food intake to support their own preferences.

The more of a particular food you eat, the more microbiota that feed off it will survive, and continue to drive your cravings for those particular foods. This is why a varied diet is recommended; it will feed several different species of microbiota, leading to more competition and each distinct signal trying to sway your cravings will be lost in the masses.

Happy Holidays!

- Lucas Roldos

Disclaimer: The information provided is meant to spread knowledge and induce interest for educational purposes. It is based on limited research. We try to pull the overall message of the literature, but further research may be necessary.  What is done with the information or suggestions is solely the consumers decision. The information provided is not meant to treat or diagnose any medical condition. References are provided for informational purposes only and do not constitute endorsement of any website or other sources.

References provided within the text as hyperlinks.