Can Yacon Syrup Really Help You Lose Weight? An Objective Look

Young Woman Holding a ScaleA sweet-tasting syrup that can help you lose weight?

Seems almost too good to be true…

But this is exactly what they’re saying about Yacon syrup, which recently became popular as a weight loss aid.

In contrast to most weight loss supplements, it does have some actual human research to back up the claims.

This article takes an objective look at Yacon syrup and the studies behind it.

What is Yacon Syrup?

Yacon syrup is extracted from the roots of the Yacon plant.

The Yacon plant, also called Smallanthus sonchifolius, grows natively in the Andes mountains in South America.

This plant has been eaten and used for medicinal purposes for hundreds of years in South America.

People there believed it to have powerful medicinal properties, leading to improvements in diabetes and helping with kidney and digestive disorders (1).

This is what the Yacon root looks like… kind of similar to a sweet potato:

Yacon Roots

The juices from the roots are extracted, then filtered and evaporated in a chemical-free manufacturing process that resembles the way Maple syrup is made. A very natural process (2).

The final product is a sweet-tasting syrup, with a dark color and a consistency similar to molasses.

Yacon syrup recently became popular after it was featured by Dr. Mehmet Oz, a famous TV doctor in America. He called it a “metabolism game changer” and seemed very excited about it. You can watch the episode for free here.

Keep in mind that Dr. Oz has a history of recommending things that don’t work (like the ineffective Garcinia Cambogia) so his endorsement should be taken with a grain of salt.

Bottom Line: Yacon syrup is extracted from the roots of the Yacon plant. It is a sweet-tasting syrup with a look and consistency similar to molasses.

The Active Ingredient in Yacon Syrup – Fructooligosaccharides

Dark Syrup Leaking From a Spoon

Yacon syrup is one of the best dietary sources of fructooligosaccharides (FOS).

The exact amount may vary between batches, but Yacon syrup contains roughly 40-50% fructooligosaccharides.

Fructooligosaccharides are sugar molecules that are connected in a way that makes them unrecognizable by the digestive system.

Even though these sugars can stimulate the taste buds, humans can not digest them.

Yacon syrup does contain a small amount of digestible sugars though… fructose, glucose and sucrose. The rest is fructooligosaccharides and a fiber called inulin (3).

Because a large part of Yacon syrup isn’t digested, it has only a third of the caloric value of sugar, about 133 calories per 100 grams, or 20 calories per tablespoon.

For this reason, it can be used as a low-calorie alternative to sugar.

The fructooligosaccharides eventually reach the large intestine, where they feed the friendly bacteria in the digestive system. This is where Yacon syrup works its magic… in the gut.

The friendly bacteria in the gut are actually incredibly important for the health of our bodies. Having the “right” types is associated with a lower risk of diabetes, better immunity and improved brain function… to name a few (4, 5, 6, 7, 8).

When the bacteria digest the fructooligosaccharides, they also produce short-chain fatty acids that have powerful anti-obesity effects, at least in rats (9, 10).

There is also some evidence that fructooligosaccharides can lower the hunger hormone ghrelin, helping to reduce appetite (11, 12, 13).

Keep in mind that Yacon is not the only food that contains fructooligosaccharides. They are also found in smaller amounts in artichokes, onions, garlic, leeks and various other plant foods.

Bottom Line: The active ingredients in Yacon are Fructooligosaccharides (FOS), which feed the friendly bacteria in the intestine and lead to various beneficial effects on metabolism.

Does Yacon Syrup Really Work For Weight Loss?

Pretty much all of the claims behind Yacon syrup rest on this one study:

Yacon syrup: Beneficial effects on obesity and insulin resistance in humans.

This study was a double-blind, placebo-controlled clinical trial. The participants were 55 obese women with cholesterol problems and a history of constipation.

The women were split into two groups… 40 women took Yacon syrup, while 15 women took another type of syrup with no active ingredients (placebo).

All of them were advised to eat a low-fat diet and mildly restrict calories. The study went on for 120 days, about 4 months.

These are the results:

Yacon Syrup vs Placebo, Weight Loss

After a study period of 120 days, the women in the Yacon syrup group had lost 33 pounds (15 kg) on average.

At the same time, the placebo group gained an average of 3.5 pounds (1.6 kg).

They also saw reductions in waist circumference:

Yacon Syrup vs Placebo, Waist Circumference

The women in the Yacon syrup group lost 3.9 inches, or 10 centimeters, off of their waist. No significant change in the placebo group.

There were several other effects noted in the Yacon syrup group:

  • Their Body Mass Index (BMI) went from 34 to 28 (From obese to overweight).
  • Their stool frequency increased from 0.28 per day to 0.99 per day, effectively curing them of constipation.
  • Fasting insulin levels went down by 42%.
  • Insulin resistance, a major risk factor for diabetes and heart disease, went down by 67%.
  • LDL (the “bad”) cholesterol went from 137 mg/dL to 97.5 mg/dL (a 29% decrease).

Overall, the women taking the Yacon syrup had dramatic improvements in both body weight and metabolic health, while the women taking the placebo stayed pretty much the same.

However… before you start jumping up and down of excitement, keep in mind that this is just ONE fairly small study. It is highly likely that other studies will lead to different results.

Studies on other types of soluble fiber have shown some amount of weight loss, but not nearly this impressive (14, 15).

Anyway, the study was fairly small and had a number of flaws.

Although I personally believe that Yacon syrup can work, the skeptic in me finds it hard to believe that a syrup could have such a strong effect.

It’s also important to keep in mind that even if Yacon syrup truly works this well… it is still a short-term effect. Lots of things can make people lose weight, it’s keeping it off that is the real challenge.

Bottom Line: In one study, women taking Yacon syrup lost 33 pounds over a period of 120 days. They also saw dramatic improvements in metabolic health.

Other Potential Benefits of Yacon Syrup

Apple and Calculator, Large

Due to the high amount of fructooligosaccharides, Yacon syrup has various other health benefits (16).

This includes reduced symptoms of constipation, which is a very common health problem.

In one study, Yacon syrup reduced the transit time through the digestive tract from 60 to 40 hours and increased stool frequency from 1.1 to 1.3 per day (17).

There is also some evidence that it can lower blood sugar, although this needs to be studied a lot more (18).

Fructooligosaccharides effectively function as soluble, fermentable fibers… which have various other benefits. Yacon syrup is also high in antioxidants and potassium (19).

Bottom Line: Yacon syrup is effective against constipation and may lower blood sugar levels. It is also high in antioxidants and potassium.

Side Effects, Dosage and How to Use it

Young Woman With Stomach Ache

Yacon syrup can have some side effects if you eat too much at a time.

It is very similar to the side effects you get by eating more soluble fiber than you’re used to.

When a lot of it reaches the intestine, it can cause excess gas production.

This can lead to flatulence, diarrhea, nausea and digestive discomfort.

For this reason, it is best to start out with a small amount and then work your way up.

If you have problems with diarrhea, then you might want to avoid Yacon syrup altogether. It can make things worse.

The dosage used in the study was roughly 10 grams of fructooligosaccharides per day, which amounts to about 20-25 grams of Yacon syrup per day (about 4-5 teaspoons per day).

In the study, they took the syrup about 1 hour before meals. An effective dosage may be 1-2 teaspoons (5-10 grams) before breakfast, lunch and dinner. Start with 1.

You can also use Yacon syrup as a sweetener, but keep in mind that you can NOT cook or bake with it, because a high temperature (anything over 248°F or 120°C) will break down the structure of the fructooligosaccharides (20).

It is possible that the timing matters. Taking it 30-60 minutes before a meal may be a more effective way to reduce appetite than eating it with a meal.

If you want to try it out, then make sure to buy 100% Pure Yacon Syrup. There shouldn’t be anything else added to it.

It is also possible to get other supplements with fructooligosaccharides, most of which are much cheaper than Yacon syrup. Whether these supplements will have the same effect is not known.

It’s Worth a Shot, But I Wouldn’t Get My Hopes Up

A sweet-tasting syrup from the Andes that can help you lose as much weight as an extreme weight loss diet?

You know what they say… if it seems to good to be true, then it probably isn’t true.

That being said, the results of that one study are promising. Although Yacon syrup is far from being scientifically proven to work, I suppose it is worth a shot if you’re curious about it.

It might turn out to be an effective tool for short-term weight loss, but don’t get your hopes up and expect some syrup to be a permanent solution to your weight problem.

If experience has taught us anything, it is that most weight loss “gimmicks” don’t work… at least not in the long term.


  1. Well written and informative, Kris. Thank you. Yacon syrup does, indeed, sound promising as a natural means of improving health and shedding fat.

  2. Great stuff! I hadn’t heard about this supplement, but I’m a big fan of doing nice things for my gut flora.

    I just got back some cruddy fasting blood sugar readings and had to reign in my poor eating habits. Perhaps adding some FOS to my new regimen wouldn’t be a terrible idea, and a man can only eat so many onions before the world turns on him.

  3. Do you think taking the capsules of this stuff would be as affective as the syrup? I’ve found a couple versions in veggie capsules, 500mg per capsule.

    • Do you mean capsules of fructooligosaccharides?

      I really don’t know… FOS is believed to be the active ingredient in Yacon syrup. I suppose it is possible that there is something “special” about the composition of Yacon, or some other ingredient as well that has some effects, but it hasn’t been tested.

      It is also possible that having something 30-60 minutes before a meal is the trick and that the timing matters. Having a tablespoon or two of oil between meals is a pretty effective way to reduce appetite IMO, maybe the same applies to the syrup.

      • Love your article. Well written.

        Are you suggesting that a spoonful of olive oil between meals will help curb the appetite? It makes sense?

  4. Diane McCarthy says:

    Hi Kris,
    Would I be able to use the yacon syrup in my coffee as a sweetener?

  5. Hi there, I have the same question as Diane, which is yacon syrup in my coffee as a sweetener? Please let us know, thanks so much. Great blog :)


    • Well, the only study didn’t do that, the women took the syrup 30-60 minutes before a meal in its raw form.

      It is possible that it would have the same effect used as a sweetener, but it is also possible that consuming it before a meal is part of the reason it reduces appetite. So I really don’t know, you’d have to try it yourself to find out.

    • Lynda Maides says:

      I am just trying the syrup. I have found the taste to be great from a spoon but it makes my coffee taste bitter. So, I am not using it in coffee like I thought I would.
      It’s too early to see weight loss benefits but hope to report later with that.

  6. I’m growing a yacon plant. Would the benefit be there if I just eat it raw and don’t turn it into syrup?

    • I really don’t know, but I think it is worth trying out. They only used the syrup in the study.

    • Yacon root has to be composed primarily of soluble fiber in order to achieve the high quantity of FOS in the syrup extracted from it. Logic dictates that increasing your soluble fiber intake may slow down bowel motility, if you consume the whole plant, leading to constipation.

      I would focus on the extract to avoid the consequences, because the syrup seems to increase bowel motility and improve regularity.

  7. With regards to weight loss, I read an article recently that said a lot of cardio done at 65% effort can actually make you gain weight because your body tries harder to hang onto fat. I’m training for a marathon, which requires a lot of steady-state cardio (of course).

    So, I have 2 questions: 1) am I harming my metabolism/thyroid/ability to lose weight by running so much each week, and 2) would a supplement like BCAAs or something else offset any negative effects of steady-state cardio? Thanks!

    • Hey Rita,
      Not sure if this helps or not – someone who I work with who bodybuilds told me that doing too much cardio actually puts your body under stress and will make your body release cortisol.

      I was doing a fair bit of cardio (2 hours or more when I’d visit the gym 4-6 times a week) and couldn’t figure out why I wasn’t losing. I cut out all of the cardio, and stuck to a healthy diet and then started to lose…

  8. Hi Kris, I’m on a LCHF diet. Will taking yacon syrup affect the ketones in my body and push me out of ketosis? Thanks for your help.

  9. Hi,
    I just bought my first bottle yesterday and took first dose this morning.

    1. Took in my coffee, loved it, but NOT 30 mins before BF.
    2. My brand is 60 caloriess per tablespoon and most I’ve read about are 21 per tablespoon, so a bit confused there.

    Will keep it up and see how it goes!

    Oh yeah, definitely read the label before you buy. 100% only and even then, like mine vs others, it can be confusing! Only time will tell!

  10. Hi Kris, thanks for the well-written article. I thought it was very informative and objective, which I really appreciate.

    You mentioned that Yacon Syrup breaks down at high temperatures, but I can’t find any more information on that, do you know how high?

    I drink 3 – 5 cups of tea a day — I have diabetes and I use “the pink packet” of artificial sweeter in my tea (it’s one of the few vices I am having a hard time letting go of).

    I thought it might be a good idea to try adding it to my tea within the 30-60 minute pre-meal window; but, if the heat of the tea would break it down, that seems like a bad idea.

    Most tea is brewed around 150-220 degrees, and drank at 100-140 degrees. Thank you!

    • According to one source, it starts breaking down when the temperature goes over 120° Celsius, or 248° Fahrenheit. I will add this to the article.

      So, adding it to coffee or tea shouldn’t degrade the active ingredient, but I would only add it after it has been brewed.

      Please keep us posted on your results.

    • Anna, to answer your question about the temperature it can be used in; if you read Kris’ article it states the syrup breaks down at “(anything over 248°F or 120°C)”.

      Maybe you missed that part towards the end of his article.

      Great article Kris. You’re one of the few people whose articles I’ve come across which is not only well written but sounds believable without sounding like you’re pushing the product towards sales.

    • Wait until the tea cools a bit and then add the syrup. I use honey in my tea and it has the same concept.

  11. Dawn Vicknair says:

    Hi Kris,

    Great article! Where can I find/buy Yacon Syrup if I want to try it?


  12. I am planning on giving Yacon syrup a try. I don’t have a lot of weight to lose (15 pounds), but would love it if waist reduction, digestion, etc. were positively impacted. Haven’t been able to buy Yacon locally, however, so I’ll have to resort to online purchase.

  13. I am. Currently on Jenny Craig and lose about a pound a week. I have just started adding this to my tea or coffee before my meals. Let’s see if it has any effect. A tip for adding to tea, also add a little lemon as the flavor of the syrup is a bit potato like. The lemon balances it out.

  14. Karen Crowder says:

    Going to try it, just got my first bottle today. Tastes yucky, but will see what happens. Even if it helps digestion that will be a good benefit. No hunger and weight loss would be an even bigger benefit. If it does not work I don’t have to order another bottle.

  15. Idania Bello Amor says:

    Totally love this article. Very informative. I am going to give it a try. Will let you know how it goes.

  16. I am experiencing some stomach discomfort. I had food poisoning a couple weeks ago. I may not be back to normal. On my second day on yacon syrup, I stopped. Do you think 2 tsp a day can cause this problem?

  17. I just got my jar today and I LOVE IT! I just ate a couple teaspoons of it.

    I tastes like a cross between a few different things. Raisins, molasses but less sweet, and apple butter. It has a smoky after taste as well. It is super good.

    I am on a very low carb diet and am a sugar addict so I got it to help with when I get sugar cravings. I found a site that sells it for the best price and I like these people and what they stand for so I am going to support their cause.

    My syrup even came with a handwritten letter.

    I will post again if I see any changes in weight or what not.

  18. Can guys under 18 drink this?

  19. Taryn Montoya says:

    Found 100% pure yacon syrup at Whole Foods on Tuesday and have been taking a spoonful before breakfast, lunch and dinner. Being positive and already had more energy last night to do things around the home. Will check in with my progress.

  20. Will the Yacon syrup lower my blood glucose levels?

  21. Juliette Tacon says:

    Good article. Hope to get some Yacon syrup and try it. Currently I mostly use honey. Will be interested to see results, if any.

  22. I would like to try this product as I also have some digestive problems, and want to lose a bit of weight. I’m willing to try any sugar substitute and don’t like aspartame or any sweeteners that don’t break down in the body. I live in Canada, so hopefully our health food stores can supply it.

  23. All the claims on this syrup are based on FOS and Inulin. Both FOS and Inulin have been around for decades, but no one has ever lost much weight or waist circumference with either. FOS is available in capsules for a fraction of the cost of the syrup.

    FOS acts as a starter and food for the good bacteria in the gut, so the digestive/constipation benefits are real. But weight loss? Maybe if a person of full of s..t, they will lose weight as they start becoming more regular.

    • Given that there is a correlation between gut bacteria and weight loss, it is conceivable that a food source high in both FOS and inulin could help to rebalance a person’s microbial profile, supporting the growth of good bacteria, which in turn would support improved metabolic functioning and weight loss.

  24. Juliette Tacon says:

    Tried Yakon powder. May or may not do all the things claimed but IT IS NOT SWEET!

  25. Do you receive the same benefits from the pill form? I know sometimes when you change the property of the item, you lose the benefits.

  26. Judy Viveiros says:

    Was just wondering if it would be safe for people with hypoglycemia, as it may lower blood sugar. Thanks.

  27. Hi, I would like to try yacon but I don’t know which one. There are so many types. Which one is the best to buy that actually works? Thanks.

    • Marvin Moss says:

      I started taking Yacon and 5 days later I had pancreatitis.

      I wonder if there is any connection since I am a non-drinker and also lost my gallbladder 20 years ago.

      • Kathy LeCompte says:

        Did the guy who got pancreatitis take Yacon as suggested?

        I also had my gallbladder taken out, I was thinking of trying this stuff, but now I’m not so sure.

  28. Brenda McFarlane says:

    When the product is opened, does it need to be refrigerated?

  29. Hi Kris, thanks for your article. I have just bought Yacon and have tried it for the past couple of days. I do not have lots of weight to lose, about 10-15 pounds, but I have other family members that could benefit. I am the tester. I have bought 100% organic Yacon syrup from Amazon. Personally, I don’t love the flavor and the smell is a little off putting to me, but I have taken it two ways. In my tea, which was not my favorite way and right off the teaspoon. I don’t find it super sweet, but it has a molasses quality. We will see what happens from here. Thanks again for your article, it was very helpful. :)

  30. Hi Kris, I am interested in adding Yacon to my diet. I research what brand to buy and they all promise the same effects. Do you have a brand that is 100% pure? I have to tell you that I am from Colombia and the raw product it’s available and very popular right now.

    It is recommended to eat it two or three times a day on your diet … Unfortunately it is not available in the USA. So any recommendation of a good brand? Thanks for your advice.

  31. Have taken 3 bottles of garcinia cambogia and only found the first bottle helped with appetite. So was wondering if the stuff really worked for anyone before I bought anymore. I can see a bit of difference in body composition but no actual weight loss.

    Seems that I might have gained some but we did have the holidays. So was interested in this syrup thingy. I think, like my doctor said, “there is no magic bullet, unfortunately” and the only thing that really works is diet and exercise. Sadly, I think that is true.

  32. Great article, thanks.

    So I ordered some 100% Pure Yacon Syrup from Sunfood a few days ago and got in in today. I tasted it, and it tastes like a raisin syrup: for example, if you took some raisins and somehow made them into a syrup, that’s exactly what yacon syrup tastes like.

    It is sweet; it’s not bitter or anything… I can’t wait to see if I experience any benefits from it.

  33. Thanks, Kris. Very informative and I would like to share my experience with others.

  34. Hi, I just started yacon. First day I had diarrhea. I didn’t take it before meals, I took it with. I will try 30 before.

    I have been exercising, stretching and little cardio, I have been eating small meals and I am not hungry. I don’t eat after 7pm. I have consistently lost 1-2 lbs a day in the past 3 days.

    The lack of hunger after is noticeable, however, before I eat I am ravenous, and I now realize I need a schedule to eat so I give 30 min before. Also, I have not had any starch or simple carb in 5 days and plan not to for a few months. I use the 100% organic.

    I will let you know what happens.

  35. I’ve been taking yacon in moderate amounts, for a month now. Moderate means that I only take it in the morning with my yoghurt. I have found no significant weight loss. The thing is though that the syrup does have an influence on my appetite.

    After my breakfast I feel full for at least three hours, while with a “normal” breakfast (plain yoghurt, eggs or -aaaargh!- whole wheat bread) I have the need to eat more afterwards. At first I thought that maybe it could also be a reaction of the fact that I do actually eat breakfast (which I didn’t consequently before) every day, but I also find that my appetite disappears when I eat the yacon yoghurt in the evenings. (For example when I when I wasn’t in the position to use my bottle of syrup, in a hotel or with friends, I ate it when I got home.)

    I think it has to do with the high fibre nature of the stuff and that you would definitely feel a shift in appetite when used thrice a day.

    I don’t want to become dependent on it, and I really don’t like to eat a spoonful of the stuff pure. Brrr. But in yogurt or smoothies it tastes great.

    It’s good stuff, I think. I like using it and I can recommend it.

    But it’s not a miracle-worker, alas.

  36. I eat yacon roots as part of my meals. Some of my clients have used yacon syrup for weight loss and digestive problems, and they like the results!

  37. Christina says:

    Would this be considered a probiotic? I’ve read some scary things about probiotics, especially that they will often feed bad bacteria as well a good bacteria. Example would be feeding a urinary tract infection, which could potentially go into sepsis.

  38. Thanks for the well written review Kris… I think, I should try to lose my weight.

  39. I am stationed overseas and ordered Yacon from Amazon. I am on my second week and so far, so good. Instant digestive changes. GREAT FOR ME since I am a teacher and my eating habits are always off. I have yet to step on a scale, but I have had to pull out my belts to hold up my clothing and my energy levels are so high. Promising.

  40. Read your article, bought the Yacon syrup, it came in the mail today. Will start regimen tomorrow. 203# 46.5″ waist.

    Will keep you posted.

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