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fructose and low carb (ketone) diet


https://www.ncbi.nlm.nih.gov/pubmed/23390127

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4405421/

I'm no expert but that took me about a minute.. I realise that epidemiological studies and meta analyses are not flawless in their findings and that without locking people up and making them ill through their diet there is no exact science that can prove conclusively what you or indeed I am implying but a suggestion that fructose (like other carbs) is bad for Type 2 diabetics doesn't sound outlandish so I avoid it except as a rare treat.
 

The first study, or rather - the abstract - actually proves nothing and does not claim to. The 2nd paper is not a study - it is theory based on other studies and the 'in theory' metabolism of fructose - and it is jaw dropping.It proves nothing either. Its main findings are based upon fructose intakes beyond what most people consume. As mentioned - isotope studies show the fate of fructose. It does not potentiate de novo lipogenesis and it does not promote adiposity, It does not raise blood sugars in the way glucose does either

I was once very interested in fructose, its potential as a unregulated source of NEFA, was interesting to me. However real studies looking at its metabolism show that unless consumed in quantities far exceeding what we currently ingest - it is not the smoking gun that people such as Lustig argue that it is. It is good that you are so interested in this stuff, if I was Diabetic I would never stop trying to understand it.

There is a lot of grey areas with diabetes management and we are not there yet with the optimal dietary approach to its management or even, to stop its aetiology. But I am certain that fructose is not where we should be looking
 
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Fine but it is still inadvisable for someone trying to follow a ketogenic diet no?

Out of interest is there anything that only contains fructose? Is it possible to purchase it? I'm quite happy to try some and see if it raises my BG as you seem very certain that it won't. From my brief reading it seems that pure fructose does not exist in nature. As someone who eats minimal carb I would probably be an effective guinea pig.
 
Probably the nearest you will find to that is Sweet Freedom Fruit Syrup which is made from natural fruit extract.. apple grapes and carob.. it says it is suitable for diabetics as it is low in fructose and it does not have any other sweetener in it. I have it if I need a bit of sweetness for frozen fruit it has very little impact on my BG levels
 

I was looking for 100% fructose to test the claim that fructose doesn't raise blood glucose levels.
Holland & Barrett may do something will check it out next time I am in town.
 
All a bit academic really - fruit raises my BG levels - if it is not the fructose doing it, well then it is something else, but I have to regulate my fruit intake or see my BG levels go into double figures.
 

I see no reason why a ketogenic diet cannot be trialled by someone with type 2 diabetes, low CHO and ketogenic diets are very interesting from a metabolic point of view - colleagues of mine would disagree (as I think you are aware) - however I have seen no evidence of it being dangerous for weight loss or glycaemic control in T2DM. Indeed, I have used quite extreme ketogenic diets for epileptic patients - nothing untoward occurs. I will say that I disagree with the mechanism put forward regarding why ketogenic diets/low CHO diets might work (for weight/fat loss) - namely that it is the fault of insulin. Nonetheless, I accept we do respond differently to nutrients and so I would always explore alternative diets if one I have recommended does not work. My job is simply to ensure the diet will not harm and is nutritionally complete.

As for pure fructose - it does not exist in nature in isolation and (off the top of my head) the reason is likely due to its poor absorption - we have no fructose specific transporters that can get it into cells - so fructose tends to hitch a ride with glucose (via glucose transporters) to more readily enter the cell. This is (likely) why fructose is found with glucose in varying ratios. I think a 1:1 ratio is optimal for absorption (don't quote me on that) - it is this poor absorption which implicates fructose with many functional GI issues such as IBS.

I know H & B do a 100% fructose powder - I think it is brilliant that you would put yourself forward to trial it - we need more of this to understand diet and its effects. I would not be concerned at all if you did this (if you ingest a not too unreasonable amount that is - I can't cite a specific amount at this point) and would be very interested in your findings. As mentioned, fructose does have potential to have adverse effects beyond the equivalent amount of glucose such as upon blood lipids but the amounts needed to evoke this are very high - and even then a positive energy balance is needed to fully explore these effects. Fructose is not an issue at current levels although I am not advocating its consumption, it is not essential for health and can be omitted entirely with no effect.

I will quickly add - a fraction of fructose does get converted to glucose however I understand that conversion is slow meaning glucose clearance is not affected to any noticeable amount. This would explain the lack of a rise in blood sugar however I can't fully elucidate the reason for why the glucose produced from fructose has no bearing on glycaemia - I never pondered this until just this second - I will look into this fr you. However, the literature is clear regarding fructose and blood sugar effects so over to you and your personal trial - if you want to.

Many thanks.
 
Sean_Raymond said:
I see no reason why a ketogenic diet cannot be trialled by someone with type 2 diabetes, low CHO and ketogenic diets are very interesting from a metabolic point of view -
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That's because there are no reasons.. I was talking about fruit being inadvisable for someone trying a ketogenic diet not the viability for a ketogenic diet for controlling Type 2, maybe I was unclear. Indeed a large amount of people on this forum have had significant anecdotal success with and LCHF or Ketogenic diet myself included.
You seem far more informed than the average HCP. Can I ask in what field you work?
 
Sean_Raymond said:
As for pure fructose - it does not exist in nature in isolation
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So in a way my experiment would be completely meaningless..even if fructose doesn't raise my blood glucose it would have no bearing whatever on whether Type 2's should be eating fruit as it would be impossible to find a fruit with only fructose. Whether it did my liver any good or not would not really be measurable either...
 

I agree - due to the CHO content in fruit very low CHO to ketogenic diets should omit them. Get the amount of allowable CHO from vegetables. From a vitamin point of view, veggies outdo fruit - fruit is just a fantastic source of Vitamin C. The loss of fibre from no fruit intake can also be made up by vegetables. In terms of antioxidants and polyphenols - fruit IS a great source of these however their potential in health is only beginning to be realised & in my opinion provide a great reason to consume fruit if you can.

The only concern I do have from a low CHO/ketogenic diet is the potential lack of fibre - effects of fibre upon the flora and fauna of our gut is an exciting area in nutrition, with many of the discussed conditions such diabetes having at least some link within microbiome disbiosis and associated dysfunction. I am not experienced enough in ketogenic diets to have considered fibre intake however it would seem possible to get 18-30g per day from such diets?

I am a Dietitian, have been qualified for almost 3 years, only now have I started to find the confidence to begin exploring nutrition beyond the boundaries set by the strict guidance we must adhere to. Low CHO is starting to be discussed more, and my training actually pushed me to consider the metabolic effects of CHO - sadly this becomes lost once qualified and many Dietitians, so talented and so well trained, unfortunately seem to become very inflexible in their approaches. Some of this is imposed upon by the need to remain qualified (so employable) and only promote 'evidence' based advice to remain 'safe'. Low CHO is evidence based in my view.

I have a deep interest in nutrition and have joined this forum for a few reasons, to help - but to learn. People like you will teach me more than a book will. I am well aware of that. Theory is great - but I have to understand how to integrate this into a practical manner. I can see you have lost almost 30kg - that is a remarkable accomplishment, especially in under 18 months. Well done. That in itself is something I know I could learn a lot from because I have never managed that with any of my patients/clients.

The experiment you mentioned is redundant from a diet point of view, because we do not eat 100% fructose as you say - however it would help dispel concern over fructose and blood sugar. The studies have been done for us regarding this. But I may do it myself as I can get access to blood monitors pretty easily. I will let you know.

Sorry for rambling.
 
Maybe you need to investigate fibre as well..
There are a significant number of people who follow a zero carb diet with no fruit or veg at all only animal products.
They report the benefits of this way of eating in helping with a number of medical conditions with very few digestive problems. I tried it myself for a month with no ill effects without unfortunately the hope for weight loss but I may well try it again sometime.
Good for you for trying to break out of the orthodoxy of your training.
 
I bet my low carb foods contain a lot more fibre than the things I leave off my shopping list - cake, trifle, white bread, batter coatings and the other 'normal' elements of the modern diet have loads of carbs and little fibre - if any.
The low carb veges I eat, the salads which are a regular feature of my meals all contain fibre. A snack might be celery and cream cheese for me - lots of fibre, where a non diabetic might go for cheese and biscuits.
I am often puzzled by the way a low carb diet is regarded as new and strange, totally unknown territory, when it has been around for a very long time - look up Banting - and what about the thousands of patients of Dr Atkins? The medical profession seem to have been applying the Nelson effect to low carb for a very long time and it is not to their credit.
 

I was mentioning my concerns regarding a potential lack of fibres effect upon the microbiome - not so much bowel movements. It would take longer than 1 month to see the effects of gut bacterial dysbiosis due to poor fibre intakes. As mentioned, this is an area we are only at the beginning of understanding however fibre is intimately connected to its health. Regardless, as a previous poster mentioned - he/she gets more fibre on their ?ketogenic diet than they did previously so adequate fibre intake is probably possible. I'd advise anyone on these diets to carefully consider their fibre intake, optimising it if otherwise indicated (some people simply do not tolerate fibre).
 

 
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