Are Simple Sugars Better Than Complex Carbohydrate?

The Skinny On Carbohydrate part 3: Simple vs. Complex

If you are a fitness and nutrition nerd like me you will be aware that carbohydrate (CHO)  is a major point of contention in the realm of diet experts and amateur bloggers.  The opinions range from those who completely vilify carbohydrate and contend that it is completely unnecessary, to those who think carbohydrate should make up the majority of your calories and fat should be avoided (like the american government diet recommendations).  If you aren’t a fitness and nutrition nerd you probably have no idea all these people exist debating endlessly about one macronutrient.   You’re saying “just give me a bagel and shut up already.”

The fact remains that this is a very important debate and probably is the lynch pin for most people’s success in maintaining weight, avoiding chronic disease and general maintenance of energy levels.  Among those who advocate for the consumption of carbohydrate the debate delineates further.  This spread generally runs along a few lines.  Timing is often discussed.  What time of day and following or preceding which activities should CHO be consumed?  Total amount of CHO is obviously a point of contention.  Also, the debate includes whether we should favor Complex carbohydrate over simple carbohydrate.

Simple vs Complex

This post will discuss the difference between Simple and Complex carbohydrate and the various opinions and rationales that go into favoring one form over the other.  For the different types of carbohydrates, what are some strategies and best practices for eating?  Which foods have complex CHO and which foods have simple?  I’ll offer some science, popular opinions as well as my own opinion.  This is a pretty tricky and complex topic and like most other topics in nutrition, there is no one size fits all correct answer.  Either way it’s fun to debate and important to be informed.   Please continue reading to get the nitty gritty!

Based on my observations about people, carbohydrates always seem to be the macronutrient that people have the hardest time managing their consumption of.   Within that people seem to have weak spots for certain delivery mechanisms for CHO.  Personally for me my weak spot definitely lies in simple carbohydrates in the form of candy and really sweet things.  I’ve been known to take down an entire pound of candy from the sweets factory or a bag of skittles, a snickers bar, a chocolate bar and a pint of ice cream all in one sitting.  I however am not going to be very enticed by a bowl of pasta, pastries and cake or bread type items.  As a personal trainer working with the general public, I notice that many of my clients struggle to avoid pasta, bread and pastries.   Those items tend to exist as complex carbohydrate, but are still relatively unhealthy and basically unnecessary (and possibly counterproductive) from a nutritional standpoint.

What does Complex vs simple Carbohydrate mean?

I don’t want to get too “sciency” and lose you to the Kardashians or something, but it’s about to get real, which means some big words are going to show up on this page right now.  Basically this refers to the molecule length of the carbohydrate or how many sugars have been linked to create a larger carbohydrate molecule.  Simple sugars include glucose, fructose, lactose, and sucrose which I have covered at length in parts 1 and 2 of this carbohydrate series.  These simple sugars are also called monosaccharides or disaccharides.   These molecules are strung together by molecular bonds to form complex carbohydrates.  A complex carbohydrate with more than two and less than 10 sugar molecules combined is referred to as a oligosaccharide.  10 or more sugar molecules combined is referred to as a polysaccharide.  This is important because the combination of your complex carbohydrates will determine the eventual metabolic fate of said carb.  Complex carbohydrates are generally considered “healthier” foods, especially when they are found in a whole food source like lentils, sweet potatoes or beans.  Starch and Fiber are two other common names for polysaccharides.  Starch is digestible and becomes glucose, which we can eventually use for energy.



Fiber is basically not digestible and is processed in the colon rather than the small intestine.  This can be a good thing because it contributes to gut health and a complex gut flora.  I’ll leave it at that because gut health goes way beyond the scope of this post and my puny brains understanding.   Fiber is basically cell walls of plants called cellulose. Fiber is a great asset to any healthy diet.  Avoiding fiber containing foods will likely lead negative side effects like constipation and decreased immunity.  But the source from which fiber is derived needs careful consideration.  It’s better to get fiber from leafy greens and whole fruits and veggies than from a bowl of grape nuts.  I’m not opposed to consuming straight fiber like psylium husk or Metamucil or even resistant starch like an underripe banana or cold/raw potatoes starch.  Full discloser, I have never tried the green banana or cold potatoes, but I have heard great things from those who have.  Not only do you get the benefit of gut health, but beta hydroxybutyrate is created as a by product of the metabolism.  This can give you great energy and has shown to increase mental focus in Alzheimer’s patients. In a study published in NCBI called “Effects of beta-hydroxybutyrate on cognition in memory-impaired adults” MCT oil performed better than a placebo to improve paragraph recognition across all 20 subjects with mild cognitive impairment. MCT oil helps you to the body get easy access to Ketone bodies including beta-hydroxybutyrate.

Whether you are going extreme low carb or prefer a higher carbohydrate diet, fiber is an important nutrient to consider.   What is interesting is that beyond concern for fiber, the need for carbohydrate intake pretty much ends there.  We can create enough glucose from stored forms and actual metabolism of fat or protein that renders exogenous consumption of carbohydrate unnecessary to meet our daily glucose needs for thinking and moving.  Also, over time while in ketosis, the brain preferentially shifts to run off of ketone bodies when glucose is not readily available.  When you go very low carb and eat a high fat diet, copious amounts of ketone bodies are produced both from your own body fat and the fat you eat.  This is a tricky approach to eating.  I don’t advocate this unless you are pretty knowledgeable in the approach.   Good luck with that if you want to try it, but from a basic metabolism standpoint total elimination of carbohydrate is fine and you will be able to function at an equal or higher level to a carbohydrate laden diet.  It can be hard in virtually all social settings.  For athletes and normal people this presents some challenges, but for people who don’t mind eating tons of butter, eggs and bacon this works.  Many get bored with the diet and seek out the more fun foods like bagels, pizza, cake and sweets.

Let’s get out of the weeds


Ok I delved a little deep into some dorky words that you likely glossed over. Hopefully you are still awake and ready for me to discuss some practical ideas you may be more likely to relate to.  The complexity of a carbohydrate will determine the speed and volume of the total glucose load your blood is exposed to.  In other words, simple sugar consumption will hit your blood quickly after ingestion, while complex carbohydrate ingestion like a sweet potato will hit your blood sugar longer after ingestion.  This is an important factor to consider because this can influence subsequent meal choices and overall effects on blood sugar.   If you eat a pure glucose load, 30 minutes later all of the sugar will have been processed in the small intestine and released into the blood.  Next insulin will be released to get that sugar into the tissues.  If you are healthy and your cells respond well, this won’t be a problem, but chronic exposure to insulin can create health problems.   Including fat tissue accumulation long term.  Also, people have a set amount of sugar they can process at any given time.  This is about 25-50 grams.  If you go beyond that you are likely going to release too much insulin and cause your blood sugar to get too low after the processing.  The reason for this is that the pancreas does not specify the insulin load relative to the sugar load perfectly.  Insulin remains in the blood and the blood sugar gets too low.  For most of us the answer then is to eat some more sugar to get that blood sugar up.  This process repeats all day for most people.  Complex carbohydrate can be a good way to avoid this scenario because the sugar is released at different rates.  A potato has a certain ratio of starch and a certain ratio of glucose.  The starch takes longer to process therefor may have less of an impact on blood sugar.  Nevertheless there is still an insulin response. It may be more evenly dispersed over time, thus you can avoid the large blood sugar swings that contribute most to the deleterious effects of carbohydrate consumption.  However you will still have insulin present for extended periods of time, which tells your fat cells to store fat and not release fat.  You may avoid diabetes, but you won’t decrease your body fat very quickly that way.  The question remains which is better complex CHO or simple CHO?  I recently had a conversation with a type 1  diabetic.  Type 1 diabetics can’t produce insulin.  When they eat carbohydrate they need to take exogenous insulin relative to the CHO load.  The insulin value does not vary depending on the CHO type.  In other words, 30 grams of glucose is treated the same as 30 grams of carbohydrate that started as starch.  She doesn’t time it to correlate with the proposed delay of blood sugar elevation that you would expect from eating starch.   What this tells me is the overall carbohydrate load in terms of grams is more important than the actual molecular complexity of the carbohydrate consumed.  Then the factor becomes carbohydrate density juxtaposed with nutrient density of the item.   Obviously you would want to get the most nutrition and energy and the least insulin response.  That places lentils, beans, sweet potatoes, quinoa, veggies ahead of bread, pasta, and pastries when considering complex carbohydrate.  The problem is that many of the more healthy choices are not readily available in most stores or restaurants.  They require prep and cooking, which is great if that is your habit but requires a lot of band width for a person just getting started in changing their eating habits.  Most people will eat a smaller amount of total carbohydrate when eating beans, sweet potatoes and quinoa than when eating bread, pasta and pastries.  I looked around for studies on this topic and did not find very many great sources.  It seems like it’s a rather difficult topic to definitively study.  It seems that insulin is the main culprit in fat accumulation and even can be linked to inflammation once a person is insulin resistant.  That means that it would be wise to decrease overall exposure to insulin.  Ironically, this points in favor of consuming higher glycemic index simple carbohydrate.  When this is done insulin exposure is immediate and short term.  The problem is that psychologically this is much more difficult for a couple of reasons.  First simple sugars taste better and are harder to eat less of.  Second, if you consume too much you will most certainly experience a bout of hypoglycemia that will be tough to grit through for most people without eating another portion of carbohydrate soon after.   Or even worse you get super hungry and wait for a while only to eat a massive meal full of items you have been trying to avoid all day. It’s true that if you get out of your body’s way your blood sugar will be unregulated and you will become more efficient at this over time, but many people would have a hard time with that.   In other words it’s easier for most people to stick with low index carbohydrate, subject themselves to a steady release of insulin and avoid the subsequent crash associated with eating high index sugars.  In this case, it would require relying on the calories in vs. out hypothesis that most fail at.  It’s an interesting question though.  Does eating high index carbohydrate mitigate the negative effects of having chronically elevated insulin levels?   Whether you consume simple sugar or complex carbohydrate there will be an inulin response.

All of this information is rather vague…What do I do with it?

The main question seems to be how long that insulin response will last. Personally the strategy I use is to avoid carbohydrate in the morning.  If I eat three meals that day I typically will eat a lunch that does not contain carbohydrate of any sort.  Then at dinner I eat what ever carbohydrate I am in the mood for or is available.  This includes french fries, white rice, sweet potato, ice cream, candy, chocolate, fruit, small amounts of alcohol and anything else you can think of.  Basically after 5 or 6pm I eat what ever I want then I got to sleep.  This approach allows me to keep a stable blood sugar during the day, limit my insulin exposure and keep my glycogen stores high for my workouts.  If I don’t workout I typically have a moderate serving of carbohydrate so my total for the day might be like 60 grams or so.  Post workout my goals is to get between 150 and 250 grams, which at times can be fun, at other times can be quite a bother.  At this point I have built up a nice sensitivity to insulin and I barely feel tired or sluggish while consuming massive amount of sugar.  In conclusion, limiting exposure to high levels of insulin in the blood is critical to health, keeping inflammation low and maintaining or losing body fat.  The easiest way to accomplish this is probably to eat moderate amounts of complex carbohydrates during the day with each meal.  But this can also be accomplished my eating small amounts (20-50g) of simple sugars during the day.  Considering both of those concepts the best way to keep insulin levels low is to not eat any carbs during the day at all.  This however, many may not consider easy because the current food system is structured in favor of carbohydrate.  There is a learning curve and likely it will requiring giving up some foods you tend to prefer on a taste or comfort metric.  A comfortable system does not grow or change.   Thank you for taking the time to read this post, I hope you found it helpful

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