Book Review: Fat Chance

Looking for a good book? This is one MUST READ book! I enjoy listening to podcasts while working sometimes. My favorite podcast is Vinnie Tortorich, America’s Angriest Trainer. I HIGHLY recommend you listen to his podcast and then go out and buy his bestselling book, Fitness Confidential. I will be doing a book review of that very shortly. Vinnie has always recommended Dr. Robert Lustig’s Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity, and Disease on his podcast and after IMLP I finally had some free time to pick it up and finish it.

Source: Amazon

Source: Amazon

I’ve read a lot of books within the past month and Lustig’s is by far the best one to read. I think this book should even be a required reading book in high schools and college. That’s how much I think everyone needs to read this book. Go buy it. Now!

Who is Dr. Lustig? Well, he is an internationally renowned pediatric endocrinologist who has spent the past 16 years treating childhood obesity at some of the top hospitals in the world, such as St. Jude’s Children’s Hospital and UCSF Benioff Children’s Hospital. Sooo… I would say that he knows his shit better than those Jillian Michaels and Dr. Oz characters.

Dr. Lustig became famous for his at-the-time, very controversial you-tube video called “Sugar: The Bitter Truth.” And, yes, I think you should watch that too. Fat Chance documents the science and politics that have led to the current obesity pandemic that no longer just affects the United States, but the entire world. I went on a medial mission to Costa Rica and Nicaragua in 2011 and I was surprised beyond belief the number of overweight and obese people and the number of fast-food joints in those countries. Hell, Costa Rica has a Denny’s!

Lustig reveals and outlines all the bad research that has been conducted over the years by the government and big food. Personally, I think a lot of those scientists who were involved in many of those studies should have their PhD’s removed. It’s rather disgusting how many people will sell-out to the food industry and politicians. Ok, end rant.

The book begins by setting up a valid argument why the government’s view of “calorie in, calorie out” is bullshit. I hate that term. When discussing food with my clients I always ask them “what is a calorie?” No one has yet to answer correctly. It’s because we have been brainwashed over the years to think of food as calorie in, calorie out. That’s how you’re suppose to lose weight, right? Wrong! Believe me, I was one of those people for a long time too, but the more I read (from reputable and educated sources!!) the more I learn that I have been completely duped all my life. Lustig is an endocrinologist meaning that he is a specialist in hormones and the biochemistry of the human body.

Lustig talks a lot about hormones, ya know, since he gets hormones. Hormones have a profound effect on our metabolism and how we view food. Fat Chance outlines ways to readjust our key hormones that regulate hunger, reward, and stress. That is done mainly by eliminating sugar. Sugar is an addictive toxin to our bodies. We live in a society today that thinks dietary fat is bad. Low-fat this and low-fat that. Well, guess what happens when you remove fat from food products? The food tastes like crap and the manufactures pump it full on sugar. Read the book and find out why sugar is bad for you. I’m serious, do it.

The evolution of nutritional science is what really fascinates me. Back in the early to mid-1900’s we got the science right. And then big food and some idiots got involved. The leading cause of death today in the United States is heart disease, but in the next decade or so we will see that shift to diabetes and other metabolic-related diseases, which heart disease can be considered one. In 1957 John Yudkin, a British physiologist and nutritionist, postulated that a dietary component caused heart attacks. By 1964, through natural observation studies he theorized that the consumption of sucrose was associated with heart disease. Yudkins published numerous papers on the biochemistry of sucrose and was the first person to warn us that excessive consumption could lead to heart disease, diabetes, GI diseases among other diseases.

Now, back in the United States we have Ancel Keys, a Minnesota epidemiologist. In the early 1950s Keys spend some time in England where we witnessed a large rise in heart disease. The typical English diet consisted of high fat and high cholesterol items, such as fish and chips. He noticed that those who are well fed in both the US and UK were those who could afford meat, but also seemed to suffer the most from heart disease. In the 1960s and 1970s Keys published numerous studies indicating that heart disease patients had higher cholesterol levels than non-heart disease patients. In 1980 Keys published his “Seven Countries” study, a 500-page paper that concluded that dietary fat was the single cause of heart disease. Which, the United States government and medical community has since run with. However, there are four major problems with his thesis.

The first being that his Seven Countries study started out as a Twenty-two Countries study. The seven countries he used in his study were: Japan, Italy, England, Wales, Australia, Canada, and the US. The relationship between dietary fat and heart disease looked quite convincing when the data was plotted. However, when he plotted the other countries (Austria, Ceylon, Chile, Denmark, Finland, France, Germany, Ireland, Israel, Mexico, Netherlands, New Zealand, Norway, Portugal, Sweden, and Switzerland), the correlation was almost non-existent. He also actively chose not to include indigenous tribes, such as the Inuit, Tokelau, and Maasai and Rendille, who eat only animal fat and have the lowest prevalence of heart disease on the planet. How’s that for science? Second, the role of dietary fat in heart disease is complicated by trans fat, which has signficant scientific studies to link it to metabolic syndrome. The use of trans-fats peaked during the 1960s and most likely were not considered a variable by Keys.

Third, if you look at the correlation itself, it is a problem. Japan and Italy eat the least amount of saturated fat and have the least amount of heart disease. But, they also eat the least amount of dietary sugar out of all the countries included. How do you know if it’s the sugar or the fat causing heart disease? Fourth, Keys admits that he correlated sucrose with saturated fat, but it was not important enough to him to remove sucrose from the equation. When one completes a multivariate correlation analysis, a common statistical tool that determines whether A causes B regardless of the impact of C, D, and E, one has to do the calculation both ways. In other words, Keys would have had to hold sucrose constant and show that dietary fat still correlates with heart disease. Basically, Keys used bad science. And then the government took it and ran with the idea.

This is just one of the studies Lustig discusses in his book. He discusses many more that are just as interesting. The end of the book concludes with two sections. One is on the personal solution and the other is on the public health solution. I absolutely loved the public health section because I am a public health professional. In society today we have this notion that obesity is an individual problem. That person eats too much, doesn’t exercise and it’s their fault they are fat. Lustig will tell you that’s rarely the problem. The public health section discusses ways as a society that we can conquer the impending obesity pandemic.

Overall, you will be crazy not to read this book. Out of all the books I have read this year, this is by far one of the best ones out there. It will change your view of nutrition and the obesity epidemic. Lustig gives you the science that backs up his claims. This isn’t a diet book written by some bimbo Hollywood trainer on how to lose 10-lbs in 10 days. It’s a real book based on real science that will open your eyes and mind to the current nutritional crisis in the United States.

What are you waiting for? GO BUY THE BOOK! 🙂

~ Happy Training!

Nutrition Tuesday: What’s In Your Sports Drink? Part II

With over 60% of the United States adult population being obese or overweight, sugar gets a bad rap. Yes, lots of processed foods with tablespoons (literally!) of sugar is bad for your weight and health. However, sugar is actually an endurance athlete’s best friend!

When I say that sugar is an endurance athlete’s best friend, I’m not promoting going out and buying fistfuls of donuts, ice cream, and candy. I’m talking about simple sugars such as glucose and fructose. Back in May I wrote a post on carbohydrates: See HERE! Yesterday’s post discussed oxidation rates of CHO (aka sugar) of glucose and fructose and their affects on athletic performance.

Most sports drinks are either made with one or more of the following sugars (1):

  • Sucrose – A disaccharide (two simple sugar molecules) that is commonly known as table sugar. It is made of one glucose and one fructose molecules.
  • Fructose – A simple sugar that is found in fruit and honey. It is digested more slowly because it must be converted into glucose first by the liver. 
  • High Fructose Corn Syrup – HFCS is made using chemical processes that first convert cornstarch to corn syrup and then convert 42-55% of the glucose in the corn syrup to fructose as a way to make it sweeter (2). HFCS has been under scrutiny as a possible culprit contributing to the obesity crisis.
  • Glucose – Is the main carbohydrate found in the blood and is used to make the glycogen stored in both the liver and muscle. Dextrose is another name for glucose.
  • Glucose polymers – Are long molecular chains of glucose. These molecules are not as sweet as other molecules such as sucrose or corn syrup.
  • Galactose – Is another simple sugar. It must be converted into glucose first by the liver before the body can use it for energy.
  • Maltodextrin – A glucose polymer that is manufactured by breaking long starch units into smaller ones. It is considered a complex carbohydrate and is most commonly found in sports drinks and other processed foods. 
Some sports drinks also contain some protein. Insulin, a blood hormone, is responsible for transporting carbohydrates from the blood into muscle cells where it can be used for energy. Some preliminary research has shown that a small amount of protein added to Carbohydrates results in a stronger insulin response, which allows glucose to be delivered to muscles faster (1). This conserves stored muscle glycogen and may delay fatigue. In longer training sessions of at least 90 minutes or more, protein can be used as a source of energy if carbohydrates are not being replenished consistently (1). The protein that would be used for energy would come from muscle proteins. If protein (and carbs) aren’t being consumed, muscles would break down to provide the proteins for energy. However, one problem about carbohydrate/protein mixtures is that some people can’t stomach them. A carbohydrate/protein mixture drink is only suggested for long duration workouts over 2 hours.
How to Choose the Right Sports Drink?
Unfortunately, there is no scientific way to determine this. The best sports drink for you is the one you can tolerate at full concentration. If you dilute a sports drink so you can tolerate it, then you are most likely not getting enough carbohydrates and electrolytes, which is the purpose of consuming a sports drink versus water. Taste is important. Choose one you like and one that you will be motivated to drink throughout your workout! Another important factor to consider is the type of drink they will be serving on race day. For sprint and Olympic distance triathlons, it probably does not matter as much since the time on course is much shorter and you don’t need to carry 5000 bottles! However, in long course triathlons, especially Ironman, you will mostly like be utilizing the water stops. It’s best to try and train with what they serve on course so you can tolerate it on race day. If your a heavy sweater or if race conditions are hotter and more humid than normal, you might also need to consider the electrolyte content of the drink and/or consider taking an electrolyte pill. 

Various Popular Sports Drinks

Sports Drink
per directions
Carbohydrate (g)
Sodium (mg)
Potassium (mg)
Carbohydrate Source
Sucrose, fructose, maltodextrin, whey and soy isolates 
Maltodextrin, fructose, dextrose
EFS (2 scoops in 24 oz bottle)
Complex carbs, sucrose, fructose
Fluid Performance 
Maltodextrin, fructose
Ironman Perform
Maltodextrin, fructose, dextrose
GU Brew
Maltodextrin, fructose
Sucrose, glucose, fructose
HEED (2 scoops in 24 oz bottle)
Maltodextrin, xylitol, white stevia
Maltodextrin, soy isolates
Maltodextrin, HFSC
(Information from various product labels)
In Summary:

  • More is not better. The body can only absorb so much ingested CHO. Studies have indicated that a combined source of carbohydrates, such as glucose/glucose polymers and fructose, can have a higher oxidation rate of CHO and increase fluid delivery while decreasing gastrointestinal stress.
  • The ideal concentration of carbohydrates is between 6-8%. Gatorade has a concentration of about 6% and has the ability to empty from the stomach just as quickly has plain water. Anything above 8% will delay stomach emptying and can cause gastrointestinal distress.
  • A sodium level of about 110 mg per 8 ounces of liquid enhances taste, optimizes absorption, and maintains body fluids. Many sport nutritionists suggest a drink with at least 200 mg of sodium per 8 ounces to decrease the chances of developing hyponatremia (low blood sodium concentration) (1). 
  • It is important to choose a sports drink that you can tolerate at full concentration. Diluting the drink defeats the purpose of drinking a sports drink.
  • To calculate your sweat rate and possible hydration needs, review my post on HydrationSports nutritionists suggest consuming about 100-250 calories (25-60g) of carbohydrates per hour during workouts (2), which can come from a combination of sports drinks, gels, bars, etc.   
~ Happy Training!

  1. Seebohar B. (2004). Nutrition periodization for endurance athletes. Boulder, CO: Bull Publishing Co.
  2. Clark N. (2008) Nancy Clark’s Sports Nutrition Guidebook, 4th Ed. Champaign, IL: Human Kinetics. 

Nutrition Tuesday: What’s In Your Sports Drink? Part I

Just about any athlete (and even many non-athletes) drink sports drinks while working out. And not all sports drinks are made equally. 
I recently read an article (Ultra-Endurance Exercise: The Emerging Role of “Multiple Transporter” Carbohydrates) in the Sports Nutrition Insider and became very interested in the recent research on the subject since it’s so important to endurance athletes. I actually posted the article of my Facebook page, but I doubt anyone who read it would understand it. It’s a really great overview of the subject; however, if you don’t have a background in chemistry or physiology it’s a bit hard to understand. 
Numerous studies have found that consuming carbohydrate (CHO) during prolonged moderate- to high-intensity exercise can postpone fatigue and enhance exercise performance when the exercise duration is greater than 45 minutes (1). These effects due to CHO consumption are largely attributed to a prevention of hypoglycaemia (low blood sugar) and the maintenance of high rates of CHO oxidation in late exercise when muscle and liver glycogen levels (endogenous sources) are low (1). Athletes consume CHO as exogenous sources in hopes to “spare” the endogenous sources. 
The average 150-lb male has about 1800 calories of carbohydrate stored in the liver, muscles, and blood in approximately the following distribution (2):

Number of Calories
Muscle Glycogen
Liver Glycogen
Blood Glucose
As the carbohydrate in the muscles get used during exercise, the carbohydrate in the liver gets released into the bloodstream to maintain a normal blood glucose level and to feed the brain (very important!) and the muscles. When your glycogen stores get low, you hit the wall – or “bonk.” In one study, cyclists with depleted muscle glycogen stores were only able to exercise for 55 minutes to fatigue. However, with full muscle glycogen stores they could exercise for about 120 minutes to fatigue (2). Also, trained muscles have the ability to store more glycogen than untrained muscles (32g v. 13g) (2). 
As you deplete carbohydrate from muscle glycogen stores during exercise, your body will increasingly rely on blood sugar for energy. By consuming carbohydrates during exercise via sports drinks, gels, bars, etc., your muscles have an added source of fuel. Sports drinks also help maintain normal blood sugar levels. A normal blood sugar level is important to keep your brain fed and help you think clearly, concentrate well, and remained focus. Have you ever been out training and start to lose focus and feel light-headed? That’s a sign of bonking and that your body needs carbs to function!  
Now, when CHO is ingested, it is absorbed through the intestines into the bloodstream to be carried throughout the body and delivered to cells for energy. Studies have indicated that the peak oxidation rate for exogenous CHO is about 1 g/min (1). It has been suggested that the absorption capacity of glucose in the intestine is the limited factor for the oxidation (think metabolism of CHO) of ingested glucose. 
Numerous studies have compared the oxidation rates of various types of ingested CHO with the oxidation of exogenous glucose during exercise. The oxidation rates of ingested maltose, sucrose, glucose polymer, and maltodextrin (glucose polymers derived from starch) are all similar to the oxidation rate of ingested glucose (1). However, significantly lower exogenous CHO oxidation rates have been reported for fructose (about 20-25% lower) and galactose (about 50% lower) compared to glucose (1). One of the possible reasons that both might be lower is the fact both fructose and galactose have to be converted into glucose in the liver before they can be oxidized (1). 
Glucose and other sugars don’t just magically float through the walls of the intestine into the bloodstream. Glucose must be transported via the sodium-dependent glucose transporter (SGLT1) across the intestinal wall. Studies have indicated that it is possible that SGLT1-transporters are saturated at a glucose ingestion rate of about 1 g/min, because studies with higher glucose ingestions rates do not yield higher oxidation rates (1). Now, for all you non-science geeks out there, let’s put this in layman’s terms. Imagine that your at a football game and it’s half time. You and everyone else has consumed lots of beer. Now that it’s half time, everyone is making a beeline to the bathroom. There are two bathrooms with only 4 stalls each. There are 1000 of you trying to use those 8 toilets. Since you all are all decent people with manners, you decide not to drop your trousers and pee in the middle of the hallway, but wait in a very long line to use the toilet. This is kind of what is happening in your intestines when you consume glucose from your sports drink. There is only so many SGLT1-transporters for glucose in your intestine. Of course, glucose has to have manners too and can’t just go up to another transporter molecule and say “LET ME IN!” It has to wait patiently in line for it’s turn to use the “toilet” too.


Now, fructose is lucky because he decided to buy a sky box seat and thus has his own totally awesome bathroom. Fructose is absorbed from the intestine by GLUT-5, a sodium-independent facilitative fructose transporter (1). Several recent studies have found that a sports drink containing both glucose and fructose can enable exogenous CHO oxidation rates to reach peak values of about 1.5 g/min (3). What is also very interesting is that with an increased CHO oxidation with multiple transporter carbohydrates there is also an increased fluid delivery and improved oxidation efficiency that reduces the likelihood of gastrointestinal distress, an endurance athlete’s worst nightmare (3)! 


Let’s talk sports drinks now! There are many different sports drinks available in market today and each one is slightly different. The biggest variables between sports drinks are (4):
  1. The type of sugar or sugars used – There are many different types of sugars that are used in sports drinks. The most common are sucrose, glucose, and fructose. Each sugar has its’ own unique sweetness. 
  2. The carbohydrate concentration – Studies have shown that sports drinks with a 6-8% carbohydrate concentration is well absorbed and utilized by the body for energy. Anything above 8% concentration can delay stomach emptying and cause stomach problems.
  3. The osmolality – Osmolality refers to the number of particles in a solution. A solution with fewer particles tends to produce faster fluid absorption and solutions with high number of particles (>400) can slow fluid absorption.
  4. The sodium content – A sodium level of about 110 mg per 8 ounces of fluid enhances taste, optimizes absorption, and maintains body fluids. Higher sodium contents may stimulate voluntary drinking more than lower sodium level drinks. 
See Part II tomorrow! 🙂

~Happy Training
  1. Jentjens RLPG, Moseley L, Waring RH, Harding LK, Jeukendrup AE. Oxidation of combined ingestion of glucose and fructose during exercise. J Appl Physiol. 2003; 96: 1277-1284.
  2. Clark N. (2008) Nancy Clark’s Sports Nutrition Guidebook, 4th Ed. Champaign, IL: Human Kinetics. 
  3. Robinson S. Ultra-endurance exercise: the emerging role of “multiple transporter” carbohydrates. Sports Nutrition Insider. Available at: Accessed July 8, 2012.
  4. Seebohar B. (2004). Nutrition periodization for endurance athletes. Boulder, CO: Bull Publishing Co. 

Nutrition Tuesday (Wednesday): A Look at Carbohydrates

Yesterday I gave an overview of each of the macronutrients needed by the human body for survival. Today I will provide a more in-depth discussion of carbohydrates. I could spend days talking about carbohydrates because there are so many things to talk about, but today I just plan on discussing what exactly a carbohydrate is and what it does in the human body. In the future I plan to discuss other topics such as the glycemic index and how much carbohydrates you should include in your diet (although you should really consult with a registered dietitian to figure out what is best for your body and health). 
Carbohydrates are groups of molecules that are comprised of carbon, hydrogen, and oxygen atoms. Carbohydrates are subdivided into three main categories: monosaccharides, oligosaccharides, and polysaccharides(1). 
Monosaccharides (“mono” = one, “saccharide” = sugar) are the simplest carbohydrate molecules. These simple carbohydrates often have a sweet taste and are classified by the number of carbons that make up their physical structure(1). The three most important nutritional monosaccharides are glucose, fructose, and galactose. Glucose is the most common mechanism for transport of carbohydrates in the body and some people refer to glucose to as “the blood sugar”(1). Glucose is a naturally occurring sugar in many foods and also is the end product of the breakdown of more complex carbohydrates. Glucose can be easily broken down by the body and can be 1) used as a fuel substrate to supply energy to the body, 2) stored as muscle or liver glycogen, or 3) converted to triglycerides and stored for later use by the body(1). 

Fructose is another simple carbohydrate. It is found in fruits, table sugar, honey, and high fructose corn syrup. Table sugar, corn syrup, and honey all contain glucose and fructose, but in differing amounts. During digestion, table sugar is broken down into 50% glucose and 50% fructose(2). High-fructose corn syrup (HFCS) digests into about 55% fructose and 45% glucose. Fructose has come under scrutiny in recent years because of the obesity epidemic in our country. HFCS is made using chemical processes that first convert cornstarch to corn syrup and then convert 42-55% of the glucose to fructose to make it taste sweeter(2). Some research has indicated that fructose is digested, absorbed, and metabolized differently than glucose in ways that favor fat production. The jury is still out on fructose; however, it’s best to avoid soda and other crap that contains HFCS. 
When monosaccharides bond together, they can form more complex carbohydrates referred to as oligosaccharides. A majority of oligosaccharides are disaccharides, or double sugars. All disaccharides contain glucose and generally are represented by sucrose, lactose, and maltose(1). Sucrose is commonly called table sugar, beet sugar, or cane sugar. Sucrose contains one glucose and one fructose bonded together. Another common disaccharide is lactose, which is formed from the bonding of glucose and galactose. Lactose is commonly referred to as the “milk sugar” because it is only found in milk from lactating animals(1). Lactose can be a difficult disaccharide for some people to digest (like me!) and can result in excessive fluid and gas build up in the bowels, bloating and cramping(1). The third most common disaccharide is maltose, which is created by the bonding of two glucose molecules. Maltose is commonly called malt sugar and is produced when seeds sprout(1). The sprouting process of plants can be altered by heat in the process called malting and is the first step in the production of alcoholic beverages. 

Polysaccharides are considered to be complex carbohydrate molecules. Generally, polysaccharides are linear or complex branching chains that are composed of more than 10 monosaccharides bonded together. The two most common plant polysaccharides are starch and fiber. Starch is the storage form of carbohydrates in plants and can be digested by humans. Fiber is considered a non-starch structural polysaccharide and may be the most abundant organic molecule on the plant, but it cannot be digested by humans. The primary animal polysaccharide is glycogen. Glycogen is either stored in the skeletal muscle or liver and is composed of subunits of glucose(1). One unique characteristic of glycogen is its branched structure. Generally, a glucose branch occurs on every 8-12th glucose subunit. This branching of glycogen is very important because it allows for very rapid breakdown of the glycogen molecule into its glucose subunits to be used for energy by the body. 


As previously discussed last week, carbohydrates, mainly in the form of glucose, are used by the body as fuel. Glycolysis is the metabolic pathway that results in the breakdown of blood glucose to produce ATP. Glycogenolysis (which I did not discuss last week) is the process which glycogen stores are broken down to produce ATP. Glycogenolysis is essentially considered the same pathway basic pathway as glycolysis, but each differ in the entry point in which they enter into the metabolic pathway. Generally, because of each enters the pathway, glycogen yields three molecules of ATP compared to glucose metabolism of two ATP molecules(1).


  1. Antonio J et al. Essentials of Sports Nutrition and Supplements. Totowa NJ: Human Press, 2008.
  2. Clark N. Nancy Clark’s Sports Nutrition Guidebook, 4th Ed. Champaign, IL: Human Kinetics, 2008.

Nutrition Tuesday: Overview of Macronutrients and Micronutrients

Last week we discussed the basics of metabolism. Now it’s important to discuss what nutrients fuel the body to not only get us through exercise, but our day-to-day activities for survival. Our bodies require two different types of nutrients: macronutrients and micronutrients. 
Macronutrients are carbohydrates, fats, and proteins, which ultimately provide the energy necessary to maintain body functions at rest and during physical activities and maintain the body’s structural and functional integrity1
Micronutrients are vitamins and minerals. As their names imply, macronutrients comprise most of a person’s dietary intake, while micronutrients are essential in much lower quantities. With the deficiency of micronutrients, athletic performance in addition to normal physiologic function will suffer. However, with a well-balanced diet, a person should not have to worry about any imbalances. 
Today’s post will give an overview of each type of nutrient required by the human body. The next few days this week I will post a more in-depth look at carbohydrates, fats, and proteins. Next week I will discuss vitamins and minerals.
The Macronutrients
Carbohydrates often get a bad name, but without question, wholesome forms of carbohydrates are the best choices for fueling your muscles and promoting good health. Carbohydrates, as their name suggests, are carbon-, hydrogen-, and oxygen-based molecules that are abundant in most plant foods, especially fruits and grains1. Not all forms and sources of carbohydrates are alike. The carbohydrate family includes both simple and complex carbohydrates2. Simple carbohydrates are monosaccharides (structurally the simplest form of carbohydrates) and disaccharides (two monosaccharides). Glucose, fructose, and galactose are monosaccharides or sometimes referred as the simple sugars2. The three most common disaccharides are sucrose (table sugar), lactose (milk sugar), and maltose (malt sugar)2
Complex carbohydrates are formed when sugars link together to form long complex chains, similar to a string of pearls. Plants store extra sugar in the form of starch, which is a complex carbohydrate. Humans store extra glucose mostly in the form of muscle glycogen and liver glycogen. This glycogen will become available for energy during exercise. 

The main functions of carbohydrates are:
  • The primary function is to provide energy to the cells of the body, particularly the brain
  • Facilitate the body’s metabolism of fat
  • Spare muscle protein
Lipid is the collective name given to a vast variety of water-insoluble chemicals, including fats and oils. Fat or lipids are made up of carbon, hydrogen, and oxygen atoms. The ratio of oxygen to carbon and hydrogen is much lower in lipids than in carbohydrates, and thus lipids are a more concentrated source of energy1. There are three major types of fatty acids that can be distinguished by their molecular bonds and number of hydrogens. Fats can be saturated (the maximum number of hydrogens), monounsaturated (having one carbon-carbon double bond), or polyunsaturated (having two or more carbon-carbon double bonds)1

The main functions of fats:
  • Fats provide many of the body’s tissues and organs (including the heart) with most of their energy. Fat is the ideal fuel because it contains almost twice the energy as glucose, weighs less, and is easily transported and stored1.
  • Essential for the transmission of nerve signals that generate muscle contraction.
  • Serve as a transporter for vitamins A, D, E, and K.
  • Provide cushioning for the prevention of vital organs and insulation from thermal stress of cold environments.
Proteins are essential nutritionally because they are comprised of amino acids, which the body needs to synthesize its own proteins and nitrogen-containing molecules that make life possible1. Amino acids are the building blocks of proteins. There are 20 amino acids. Of these 20 amino acids, 9 are considered to be essential because the human body cannot synthesize these amino acids. The remaining 11 amino acids are considered nonessential because the human body can synthesize them. 

The main functions of proteins:
  • Produce antibodies for the immune system
  • Produce enzymes that are required for various chemical reactions in the body
  • Component of structural hormones:
    • Contractile proteins for muscle tissue (i.e. actin and myosin)
    • Fibrous proteins in connective tissues (i.e. collagen, elastin, and keratin)
  • Component of transport proteins (i.e. hemoglobin)
  • Component of peptide hormones (i.e. insulin, thyroid hormone, etc.)
  • Source of fuel when muscle glycogen levels are low due to prolonged intense exercise 
The Micronutrients
Vitamins are metabolic catalysts that regulate biochemical reactions within the body2. They are found in plants that we eat and are created by the plants themselves. Vitamins are categorized into either water-soluble or fat-soluble vitamins. Water-soluble vitamins are found in the fluid portion of our bodies and do not accumulate to a large degree in the body1. Fat-soluble vitamins are stored in the lipid (fat) portion of our bodies and can accumulate in the cells1. Some vitamins include: Vitamin B6, Vitamin C, Vitamin D, and Vitamin A.
Minerals are natural substances that plants must absorb from the soil2. The human body uses minerals for many different jobs, including building bones, making hormones, and regulating the heartbeat. There are two kinds of minerals: macrominerals and trace minerals3. Macrominerals include calcium, phosphorus, magnesium, sodium, potassium, chloride and sulfur3. Trace minerals include iron, manganese, copper, iodine, zinc, cobalt, fluoride and selenium3

  1. Antonio J et al. Essentials of Sports Nutrition and Supplements. Totowa NJ: Human Press, 2008.
  2. Clark N. Nancy Clark’s Sports Nutrition Guidebook, 4th Ed. Champaign, IL: Human Kinetics, 2008.
  3. MedlinePlus. Minerals. Available at: Accessed May 28, 2012. 
(Disclaimer: This is for your information. If you need help with your diet and developing healthy lifestyle choices then I suggest seeking out professional help from your medical professional or registered dietitian. If you see any errors, please let me know!)