The Difference in How Fructose and Glucose Affect Your Body

Picture of woman deciding between sugar and honey for her coffee

My regular readers know that I consider agave to be a BIG enemy to health and beauty- which is very high in fructose (up to 97% fructose). It truly irks me that sly marketing makes the general public think agave is a “healthy” sweetener, and that it continues to be used in “health” products purported to be better than regular baked or other goods, as well as in many restaurants. It is not. There is a myth that exists that fructose is a “healthy” sugar while glucose is bad stuff. In fact, in recent years, there has been a rise in sweeteners that contain this “healthy” sugar, such as the dreaded agave nectar. I sincerely hope that this information (please help spread it!) makes more people aware of the differences in sugar types, and makes more people know to avoid agave at all costs. S.O.S: Save Our Skin!!!


Fructose is one type of sugar molecule. It occurs naturally in fresh fruits, giving them their sweetness. Because of this, many people consider fructose “natural,” and assume that all fructose products are healthier than other types of sugar. Likewise, fructose has a low glycemic index, meaning it has minimal impact on blood glucose levels. This has made it a popular sweetener with people on low-carbohydrate and low-glycemic diets, which aim to minimize blood glucose levels in order to minimize insulin release. But the glycemic index is not the sole determining factor in whether a sweetener is “healthy” or desirable to use. Because fructose is very sweet, fruit contains relatively small amounts, providing your body with just a little bit of the sugar, which is very easily handled. If people continued to eat fructose only in fruit and occasionally honey as our ancestors did, the body would easily process it without any problems. Unfortunately, the traditional Western diet is extremely high in fructose, which is present in many processed foods, soda pop, baked goods, crackers, canned goods, and many others. The result is a toxic load. According to the American Journal of Clinical Nutrition, fructose intake has increased dramatically in the past few decades. The problem with fructose is that when you consume large amounts of it in its concentrated form (agave, crystalline fructose, high-fructose corn syrup), it goes straight to your liver, avoiding the gastrointestinal tract altogether. This places a heavy toxic load on your liver, which must work very hard to process it, sometimes resulting in scarring. Additionally, fructose is converted by the liver into glycerol, which can raise levels of triglycerides. High triglycerides are linked to increased risk of atherosclerosis and heart disease. According to the AJCN article cited above, “hepatic (liver) metabolism of fructose thus favors lipogenesis.” High fructose intake has been associated with:

  • casuses of obesityIncreased levels of circulating blood lipids
  • Obesity
  • Fat around the middle
  • Lowered HDL
  • Increased levels of uric acid (associated with gout and heart disease)
  • Liver scarring (cirrhosis)
  • Fatty liver
  • The formation of AGE’s* (advanced end glycation products), which can lead to wrinkling and other signs of skin aging

*Some studies show that fructose creates AGE’s up to 10 times more efficiently than glucose Bottom line: A little fruit is just fine – it contains small amounts of fructose the body can easily metabolize. Concentrated fructose in HFCS, agave, and crystallized fructose on the other hand, can cause a real health problem and should be avoided.


Another type of simple sugar is glucose, which is the most common form of carbohydrate. It is derived from starches. When you eat starches, your body converts them to glucose, which raises blood sugar levels and supplies your body with energy. Your body metabolizes glucose via the intestinal tract, causing a rise in blood sugar. In order to return your blood sugar to a normal level, the pancreas releases insulin, which is a storage hormone. The insulin binds to the glucose and carries it to the cells that need extra energy, storing any remaining energy in long-term storage (a.k.a. fat cells). Cells that need glucose have insulin receptors that encourage glucose to enter in order to efficiently utilize it. problems associated with glucoseThe problem arises when glucose is continuously high. Eating highly processed foods, simple starches (white flour, white rice), and foods containing sugar elevate blood glucose significantly. For a while, the pancreas can handle this workload; however, over time it becomes exhausted and unable to efficiently release insulin any longer. This can result in the chronically elevated blood glucose levels found in type 2 diabetes or metabolic syndrome. At the same time, because insulin release is now inefficient, glucose is no longer being delivered to the cells that need it, resulting in cell starvation. Hyperglycemia over time has been related to:

  • Decreased immunity
  • Poor wound healing
  • Nerve damage
  • Kidney failure
  • High levels of blood lipids
  • Heart attack and stroke
  • Peripheral nerve disease
  • Obesity

Bottom line: Your body will cull the glucose it needs from complex carbohydrate-rich foods including vegetables, fruits, nuts, seeds, and whole grains. Eating excess levels of starches and simple sugars can break your body’s glucose management mechanism (metabolism), resulting in numerous health problems.

Artificial Sweeteners

Many people recognize the inherent health risks of sugar and fructose, and thus turn to alternative forms of sweetness. This often occurs in the form of artificial sweeteners like aspartame and sucralose. Unfortunately, these sweeteners have their own health risks, are artificial chemicals, and are neurotoxic. Artificial sweeteners have been associated with:health effects of artificial sweeteners

  • Increased rates of cancer
  • Neurological problems
  • Headache
  • Brain fog
  • Aches and pains

What to Do

When you want something sweet, what can you do? Try some natural sweetness from a piece of fruit, a dried fig or date, or a smoothie. You may also enjoy stevia (different brands taste better than others. I like NuNaturals), which is a sweet herb or xylitol, which is a sugar alcohol that has negligible effect on blood sugar levels. For liquid sweetener needs, raw coconut nectar is great as it is only 10% fructose (compared to agave, which is up to 97% fructose) and is rich in minerals in amino acids. Even maple syrup is a better choice than agave. Besides avoiding refined white sugars and artificial sweeteners, be sure to avoid fructose-loaded sweeteners such as agave and high fructose corn syrup. What’s the one thing I want you to remember from this blog, which I repeated about twelve times? :) Here it is again: Avoid agave, agave-containing products, and restaurant dishes that include agave in their ingredient list (if you are not sure, ask!).



Last updated: Tuesday, January 5, 2016
  • Isabella

    Hey Kim!
    I am in love with raw, unfiltered honey and use it other than stevia. But since you don’t mention it a lot, I am guessing that you aren’t a big fan of it. Is it terrible?

  • Nicole

    Hi Kim,

    I was wondering if coconut milk is ok to drink everyday or should it be limited?

    Thanks 😉

  • Nicole

    One more question!

    I was reading that certain foods such as spinach, sweet potatoes, and tea act as iron absorption inhibitors. So I was wondering if I have a cup of tea how long should I wait before eating iron-rich foods?

    Thanks again 😀

  • Katie

    Kimberly, thanks for yet another great article I am truly touched by all the support you continue to give us in the community, with your blog posts, Pinterest, tweets, etc. I follow you everywhere and am so grateful that you answer my comments and tweets! I completely live the BDS lifestyle and it makes me so happy. From making my lemon water in the morning to my ginger lemon cayenne immunity tea at night you would be so proud of my lifestyle. I know how busy you must me running around for clients and as A college Student living the BDS lifestyle I’ve gotten extremely good at organizing my life with my specific eating and lifestyle, as I’m sure you have over the years.
    With all the wonderful work you do and information you provide.While my degree will be in journalism, the BDS lifestyle has made me reconsider my entire career path to include some way to incorporate my passion for this lifestyle. I just want you to know how much you have truly changed my life and it’s so great you are here for us with the blog and social media for continued support.

  • Petra

    Great summary – I have recently started avoiding all fructose and am feeling great!

  • Nadia

    Hi Kim,

    Does that mean that you disapprove of diets that use fruit as the primary calorie source?

    I’m specifically thinking of the 80-10-10 diet, by Dr. Doug Graham.

    Thanks :)

  • Lis

    Hi Kimberly, great article, thanks! What about fruit juice concentrate & other types of ‘fruit’ sweeteners, such as fruit syrups? I believe one or the other is used in the gluten-free bread I buy. I prefer a sweetener-free product, but I haven’t found one. I’d like to make my own. Do you have a simple recipe for gluten-free bread or can you recommend a good brand if the above added sweetener is not okay? Thanks for all you do!

  • MArina

    Can you talk a little more about Maple Syrup? I’ve read that it’s completely safe and doesn’t raise blood sugar. Is this true?

  • raman handa

    solves some of the mysteries out of the sugars.Good job.

  • Monica

    She does use it. All the stuff she use to make with Agave now she uses honey

  • Julia

    Hi Kimberly! Thank you for this info. I am currently taking a probiotic, and the first ingredient is ‘oligofructose’. Is this bad for me? It also contains corn starch, maltodextrin, glucose, vegetable gum, potato starch, nonfat dry milk, anti-caking agent. There are some others, but I thought this would be enough for you to let me know if I’m taking something that’s not great. Thank you xx

    • Kate

      Hey Julia – I’m sure you’ve already gotten a response to this but I say AVOID WHATEVER THAT PROBIOTIC YOU’RE TAKING LIKE THE PLAGUE! Corn starch = bad. Potato starch = bad. And as a vegan I want to say milk = bad. But for real, the two starches you really should stay far far away from. If you want probiotics drink RAW KOMBUCHA :)

      • rick

        oligofructose is a useful pre-biotic – that is, it feeds and nourishes your gut flora/bacteria and helps it to thrive and multiply — high concentrations of oligofructose are found in bananas, chicory root, onions, asparagus, garlic, wheat, Jerusalem artichokes, tomatoes, barley, leeks and jicama. I agree with Kate though that I don’t like the other ingredients at all! Corn starch? should not be in a well-designed pro- or pre- biotic, imo.

        Oligofructose is also lableled as Fructooligosaccharides. Usually it is powdered chicory root.

  • Renee

    Hey Kimberly , I am very worried because I use alot of equal to sweeten my coffee and tea, I know it’s bad but I can’t find anything that taste good. I’ve started drinking your green monster smoothie and I am so hooked on it.. Please tell me what I can do

  • Nicole

    Hey Kim,

    I just bought a bag of dried apricots but noticed on the ingredients that they contain sulfur dioxide. Is this safe, should I return them?

  • Gary

    @Isabella– Honey is natural and a much better alternative than refined sugars or artificial sweeteners. I mean, use it in moderation, but it’s all natural and I am a big believer in natural ANYTHING as aposed to something produced by man! Maybe Kim would agree!

    • Drew

      How is natural (made by bees) any different to natural (made by man) any different? Honey is still very high fructose so I don’t understand this argument. I think that this whole fructose thing has gotten way out of hand. Eat fruit, honey etc. but don’t eat ridiculous amounts of them. Calories in vs Calories out is what it’s all about!

  • Julia

    Hi Kimberly, the 73% organic raw dark chocolate I buy contains organic ‘evaporated’ coconut nectar.. Is that ok? (ie same as raw coconut nectar you mention in this article)?Thank you xx

  • aleksandra

    Hi Kim :)

    Thank you so much for all the great info :) I love your book too! I just have one question, why is there almost no fruit included in the ‘true beauty’ phase? Does this mean I should avoid it? I understand that greens have to be the major part of your diet and I do eat mostly green vegetables but I also have fruit daily. How much fruit do you recommend? love alex xxx

  • http://differenceinhowfructose&gluscoseaffectyourbody-kimberlysynder Tricia Laurita

    Hi, I understand the article but for example – I eat Amy’s steel cut oats for breakfast. It is sweetened with agave. You said it is high in fructose – but what if it is used in small amounts just like the amounts in fruit? You don’t need a lot of that to sweeten food – like the hot cereal I eat from Amys. Would that be acceptable? I love your book, but for example – the natural stevia I find ridiculously sweet even in small amounts. I can’t eat it. I find using regular sugar in small amounts much less sweet so I would rather have regular sugar.
    Tricia Laurita

  • Bill

    What are your thoughts about the sweetner Truvia?

  • Danitza

    I sell organic meal bars that are sweetened with sugar alcohols and taste great!

  • Anna

    Such great info! I just can’t get used to the taste of Stevia. How do you feel about organic brown rice syrup?

    • Anna

      or date sugar?

  • Jaime

    Kim, I was wondering about organic coconut sugar? I found some at my local market, and I enjoy the taste.

  • Denise

    Good to know about the coconut nectar. I’ll look for it at my local health food store.

  • Cacao Monkey


    I wonder if perhaps you can comment on the pros/cons of
    Inulin (called a soluble fiber)
    FOS the Fructo-Oligo-Sacharide

    is Raw Dark Unfiltered Agave nectar only Fructos or is there other nutrients like metabolic co-factors?

    I want to use Dates but so many complain that it is high Sucrose. what do you think?

    hmm Maple Syrup is one of the most processed refined sugars of all and is often 95% to 99% Sucrose is that really better than Agave?
    I have heard people complain about being addicted to Maple Syrup and some super healthy people I know tell me it causes them Yeast Explosions. have you encountered any thing like that ??

    I Would go for Raw Honey but again all kinds of people complain about its sugar content. but is it sucrose, fructos or glucose or something else?

    Aren’t the alcohol sugars hard on the liver?

    so many fine details to consider. Why cant there be only one kind of honey and one kind of fruit sugar and simple whole cane sugar?

    I hope you can add to each of those sweet questions YuMmY YuM ;^)

    Cacao Monkey

  • Stephanie

    I read this article today on some of the benefits of Fructose. Of course, high fructose corn syrup in soda and stuff is quite the worst thing ever, but fructose does really seem to have its benefits as well.

  • Katie

    Hi Kim!
    I read on here you take a liquid B-12/ B complex vitamin. This is my Now brand B that I’m taking but I noticed brown rice syrup in the ingredients is that okay! I’m a Blossoming Beauty trying to kill candida so I want to be sure this doesn’t hinder my progress with that! SOS! thank you!

    Also, still no luck getting my periods to return, I’m upping my nuts and seeds and cooked food! any ideas?

    Thank you again for everything! Namaste!

  • Monica

    Hi Kim! I’m so glad you wrote this, I find it so interesting how much HARM sugar does to our bodies. Nice meeting you yesterday (I’m the flight attendant from your LAX flight haha), glad to be back to the website!

  • Lena

    Hey Kim, just wondering if you knew whether xylitol can cause headaches? I had some for the first time today and have a terrible headache.

    • Shannon Gafner-Holmes

      Absolutely! It cause a migraine in me within minutes of ingesting. It also cause bloat.

  • Nan

    Any science to back up these claims? Sounds hysterical and unfounded, scaring people is dangerous business, really let us read your scientific studies that support your words, please and thank you.

    • P. Gagne

      This has become a fascination for me as our family’s health and mental health are in need of a change in our lifestyles. I found Dr. Robert Lustig’s “Fat Chance: Beating the odds against sugar, processed food, obesity, and disease” to be a huge help in weeding through hoow to change our diets and maximize our intake of ffods while reducing toxins. The studies in this book are great and given from an endocrinologist with a great ability to explain the way in which our western diet has become so toxic. 550+ pages or nearly 10 hours in audio format, he explains in great depth the way in which Glucose is the ONLY sugar that can be metabolized by all organs, that fructose is only metabolized in the liver, and fructose is metabolized straight in fat to be stored. Great read and backs up this and many other types of claims against sugars.

      • Heike

        I wish there would be a LOVE button available on this page. I would push it many time for this comment and the mentioned reference. Thank you!

  • Natual&Organic

    We are a group of people who believe in the possibility of a better world, by simply making the right decisions everyday, specially those which impact directly on our health and our planet.

  • Faizan

    Hi Kim,
    How much (gm) fructose in diet is considered to be as high fructose or fructose rich diet?

  • Jacqueline

    I have found that xylitol gives me headaches. I never get headaches. I could not figure out what was going on until one day it occurred to me to avoid the zylitol. So I did. I went back to agave and the headaches never returned. However, I do want to consider other sweetners. I plan to give the coconut nectar a try. I’ve read also that there exists a coconut suger. Whole Foods has it. But then Dr. Daniel Amen (*Use Your Brain to Change Your Age* and *Healing ADD*) seems to like brown rice syrup. I’ll give ’em both a try. Wish me well that the headaches won’t return.

  • Rachael MacLean

    Hi Kimberley, this is a brilliant article about Fructose and Glucose and the different ways they work in the body. I am a firm believer that sugar plays a massive part on peoples weight problems and they really just need a bit of education about how it all works in the body. Thank you for sharing!

  • jonathan

    good article!
    It bothers me too that so many people are being fooled by the low GI marketing behind fructose. fructose is essentially poison. fructose ingestion causes the liver, intestines and kidneys to produce fructokinase, the enzyme needed to metabolise fructose.

    Fructokinase uses HUIGE amounts of ATP (adenosine triphosphate) which it coverts to ADM (adenosine monophosphate) which breaks down into uric acid. ADM also kills cells by depleting their energy (ATP) and the dead cells turn into uric acid.
    Uric acid damages the mitochondria and the cells store fat because they cannot convert food to energy. it also has no effect on leptin so you easily overeat!

    So fructose kills cells, promotes fat storage, raises triglyceride levels, raises uric acid levels, increases food intake and causes insulin resistance (type 2 diabetes).

    At least its low GI, though!

  • Dorothy Willwerth

    If you are contemplating what you want to do when you leave school or further education a great piece of advice is to do something that you are passionate about. You are going to be working a long time and you are now in a position of power. By laying down some carefully planned foundations now, you will be able to start out your working life, doing a job that inspires you and is interesting to you. Fashion is an interesting subject to choose for many reasons. One of the advantages of taking up a career in fashion is that there are so many branches to the subject and different roads you can choose to go down. ”

  • Jody Heath

    Does anyone know of a good article explaining why honey is a more gradual form of energy. Honey has two monosaccharides, fructose and glucose. Table sugar has the disaccharide, sucrose made up of fructose and glucose. Stomach acid separates table sugar into fructose and glucose, so that it looks just similar to honey; therefore, they both should be absorbed in the blood at similar rates, yet table sugar is said to result into a higher blood glucose level and resulting insulin spike, whereas honey is supposed to be a more gradual form of energy resulting in less of a spike. Does anyone have a scientific explanation for the glucose surge in the blood stream of table sugar vs the gradual release of glucose touted by the honey supporters?

    • Elle

      My understanding is table sugar is highly processed so enters the system as a simple sugar and honey (raw) is not processed and so your system needs to do extra work to break the bonds of those molecules to release the energy.

    • Dave

      Like agave, honey is loaded with fructose, so it has a lower glycemic index than table sugar. Therefore, like agave, it does not raise your blood glucose as fast as table sugar does. Nonetheless, too much honey is as bad as too much agave (or too much of any sugar).

    • Donique

      Hey there, carbs are only broken down in the mouth a bit by salivary amylase and mostly in the duodenum. Proteins are the only nutrients broken down in the stomach.

  • MKB

    Insulin does not “bind to glucose,” as stated above. High glucose levels in the blood cause beta cells in the pancreas to secrete insulin into the blood stream. Insulin then acts as a hormone and binds to insulin receptors of cells throughout the body, particularly liver cells. This causes cells throughout the body to uptake glucose from the blood and store it as glycogen. This lowers glucose levels in the blood back to normal levels.

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  • Elli Hartsch

    Thanks for your post. My partner and i have always noticed that most people are desperate to lose weight simply because they wish to appear slim plus attractive. Even so, they do not usually realize that there are more benefits to losing weight in addition. Doctors declare that over weight people are afflicted with a variety of illnesses that can be directly attributed to the excess weight. The great news is that people that are overweight along with suffering from a variety of diseases are able to reduce the severity of the illnesses simply by losing weight. You are able to see a progressive but notable improvement in health if even a bit of a amount of losing weight is attained.

  • Paul Mullen

    I loved your article: we need to look very carefully at the ways our modern diet differs from the diets our bodies evolved to eat. One thing puzzles me though: you (and other commentators on the subject) state ” it goes straight to your liver, avoiding the gastrointestinal tract altogether”. Really? How can something swallowed by mouth get to the liver without passing through the gastro-intestinal tract? Surely to get to the liver it has to be absorbed into the bloodstream through the walls of the stomach or intestines, so why doesn’t it raise blood sugar levels? Or perhaps it raises blood sugar levels but does not cause the pancreas to produce more insulin, so is slow to be removed from the blood stream?

    • Dr. Ashley

      You are correct in that both fructose and glucose are absorbed in the GI tract and ultimately delivered to the bloodstream through the small intestine. However, I believe what Kimberly was trying to explain was that the METABOLISM of glucose and fructose differ once delivered to the blood stream. That is, fructose is primarily metabolized by the liver (fructolysis). Whereas, glucose can be metabolized by most cells in the body (glycolysis). I believe that Kimberly tries to explain concepts that are big picture and easily understood by the average lay-person.

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  • Clare

    Excellent article
    For myself sucrose is gone
    I eat Low Carb High Fat
    It is keeping my BGL in the normal range
    I suffer no further glucose / therefore insulin spikes
    What beats me are the people who don’t seem to understand that fruit is sweet, we only need to eat a very small amount to send BGL’s through the roof
    Fruit juices are BAD
    Just stay away from the sugars, the simple carbohydrates
    Get your life back

    Thanks again

  • MIK

    Reasoning in this article seem sound, but why is it that people have been cured from brain cancer & other cancers & diseases by following a high fruit (fructose) diet (there are several testimonies on YouTube)? I just feel like there is a piece of the puzzle missing in this article. Of course any sort of processed food/sugar is crap, and that is not what I’m referring to…. I just don’t want people to be steered away from whole quality fruits because of this article…fruit might actually help someone who is suffering a serious illness. Thanks!

    • David Atkinson

      You need to re-read this article if you think she is advocating not eating fruit. The warning against Agave is basically all things in moderation, which Agave is not. Like HFCS, Agave is a very concentrated form of fructose, which is toxic to the liver. See Fructose 2.0 by Dr. Lustig on Youtube for the details on this. Fruit on the other hand delivers a much smaller concentration of fructose, glucose, and especially fiber. The fiber is essential to slowing the absorption of glucose into the blood stream, and is why eating whole fruit works for diabetics. I even supplement my fruit smoothies with additional soluble fiber, trying to get the recommended 35 grams of fiber in my daily intake. Glycemic load is the other key, not just glycemic index.

      • David Atkinson

        In the bottom line summary, she specifically says “a little fruit is fine” but I disagree with this. I think a lot of fruit is fine. In fact, I think the healthiest diet or lifestyle that exists is that of the raw vegan, which avoid all processed foods, and focus on fruits as the favored form of carbohydrate (80% of daily intake), raw nuts and seeds, and no extracted/concentrated forms of anything, but especially not oils, HFCS, Agave, crystallized sweetners, etc. See 80/10/10 diet by Dr. Graham for more details.

      • Giselle

        High fructose corn syrup is NOT a concentrated form of fructose!!! It’s half glucose and half fructose, the same as table sugar (sucrose). The difference between HFCS and sucrose is that the latter is glucose and fructose chemically combined and the former is just glucose and fructose mixed together, in equal amounts.

        • Dewey

          Spot on! You saved me the effort.

  • Sweta

    Nice article!! Very well written!! Thanks for sharing!!

  • Ema

    Hi, are you sure that stevia is a good choice? I read not less about its harmful effect and that it is not very healthy. I rather stopped eating it longer time ago.

  • http://google Theresa jayne

    I tried eating cake in vegetarian cafes thinking fructose was better than sugar lower in calorie also suitable for diabetics!! Anyway I love their vegetarian food meals not all but now I understand what fructose fruit sugar is won’t eat it anymore its rare I eat cake also I go gym regularly so n I have lost 32 Pounds up to now I do eat healthily always fruit salads etc

  • Theresa jayne

    No more cake for me

  • Theresa jayne

    Hmmm I see not impressed about fructose fruit sugar I nearly ever eat cakes at all I go gym n in four n half months lost 32pounds over two stones I like some vegetarian meals. Soups. But no more cake thought was healthy there you go you live and learn.

  • Rebecca Storch – Greenbird Liv

    very clearly explained! good writing.