The FastDay Forum

[carorees]

I spotted this report of a study comparing a "low carb" diet with a low fat diet in the BBC news website:
Low-fat diet 'burns more fat', study finds - http://www.bbc.co.uk/news/health-31763205

When I looked more closely though, it became apparent that the sofa called low carb diet was not low carb at all. It was 30% of calories from carbs which you can calculate is a bit under 200g of carbs per day. Low carb dieters know that you need to keep carbs under 100g to lose weight.

So the study appears to be designed to ensure that the low fat diet won. Sigh.

Typical. I am curled up with "Keto Adapted" by Maria Emmerich. This is one of the books that peebles alerted us to as being available for 99 p from Kindle (not sure if it still is 99p, I grabbed it straight away). She recommends 30 g carbs. I hope she has some good recipes for fishetarians.

My breakfast of avocado, 2 eggs, 2 mugs real coffee+double cream is 13g carbs and 19g protein. It's going to be hard to stay under 30g carbs. It will mean no nuts or even 99% chocolate and lots of concentration and counting :0@

So far, this is just a presentation rather than a properly-documented write-up. I do think it reflects the difficulty of designing and funding appropriate clinical trials, particularly those that involve metabolic ward data.

Of course this was trial under-powered in the number of participants, the demographics were narrow (relative youth, amongst other factors, probably indicates that IR is not a confounder here tho' I wished they'd tested for this as the participants are Class I - II obese), and it was far too short in duration for any useful conclusions to be made that might influence Public Health. However, at 30%, that is pretty much the carbohydrate level to which the majority of participants on LC trials drift after 6 months to a year, iirc. (E.g., Gardner's A to Z Study, Table 2: http://jama.jamanetwork.com/article.asp ... eid=205916 )

As Hall writes in the study abstract:

Long term extrapolation of our results is fraught with difficulties...[However,] our data suggest that the greater fat imbalance is likely to persist with the [low-fat] diet, leading to more long-term body fat loss than with the [low-carb] diet. https://endo.confex.com/endo/2015endo/w ... 20716.html

However, very low fat is what competitive Physique Architects/bodybuilders do when they're shredding for competition after a bulk. I'm no fan of bro-science but there does seem to be a solid amount of experience to support this practice. It works - for competitive Physique Architects, which doesn't mean it's grand for anyone else.

It also has to be said that it works for the collection of clinical data offered by the McDougall diet people who eat vegetarian, very high unrefined carbohydrate, very modest protein, and very low fat (all with reduced food reward).

It may well end up as a variation on most diets work if you can sustain them - what works is something that you can live with over time. But, for me, it is worthwhile to explore putative mechanisms/outcomes for macronutrient differences as a whole lot of diet tribalism is founded on the belief that some macronutrient make-ups are privileged over others for weight loss or general health.

My breakfast of avocado, 2 eggs, 2 mugs real coffee+double cream is 13g carbs and 19g protein. It's going to be hard to stay under 30g carbs. It will mean no nuts or even 99% chocolate and lots of concentration and counting :0@

Which is why I probably won't do it but any ideas that will widen my rather limited repertoire of main courses and improve my fat/protein ratio are gratefully received. And wow, avocado and eggs, are they scrambled?

[Tracieknits]

My breakfast of avocado, 2 eggs, 2 mugs real coffee+double cream is 13g carbs and 19g protein. It's going to be hard to stay under 30g carbs. It will mean no nuts or even 99% chocolate and lots of concentration and counting :0@

Which is why I probably won't do it but any ideas that will widen my rather limited repertoire of main courses and improve my fat/protein ratio are gratefully received. And wow, avocado and eggs, are they scrambled?

I'm with you Barbarita. When I've actually eaten very low carb, I've always felt sooooo sick. I can handle it for about three days before my body starts doing revolting things and I can't bear the sight of any more fatty foods. I am also missing a gallbladder, and that may have something to do with it.

[carorees]

Even if 30% of calories from carbs is where many low carbers end up, I think that a fair comparison of low-fat vs low-carb should actually use a low carb diet? And if they choose to use moderate carbs (30%) on the basis that long-term that's what low carbers eat then they should also use the fat level that most low-fat dieters end up eating which is a good deal higher than 7%, so it is still an inappropriate diet comparison whichever way you cut it!

Also as low carb diet tend to work on total g of carbs rather than % of cals, the effectiveness of the study diet likely depends on what the 30% worked out at in g of carbs for each participant.

For me, 30% of calories from carbs is 100g, so quite low but for my husband it is 270g which is quite high.

This is the problem with most Low Carb diet studies that were conducted before the mid-2000s.

Fortunately, there are quite a few that are actually discussing diets that are low enough in carbs to change the way that the body burns fat.

I've eaten the very low carb diet for long periods of time, but agree that a level closer to 60 g a day (which is still ketogenic) is a lot easier on my body than one of 30g. However, it is worth noting that most people count carbs so badly, that they think they are eating 30 g when they are, in fact, eating 60. The problem, as always, is that they can't judge portion sizes. Most people are eating twice as large of a portion of most foods as the portion sized defined in nutritional software and books.

I agree that I would find it pretty hard to stick to 30g carbs daily without feeling deprived. I eat around 70-75g (which is still relatively 'low carb' non?) and get by absolutely fine with plenty of choice as to what I eat. These things have got to be sustainable surely?

[carieoates]

For me eatimg less carbs is easy having done the whole "Atkins, Duran" thing in its day.
But fasting and low carbing now that's hard. Doable but hard.

My breakfast of avocado, 2 eggs, 2 mugs real coffee+double cream is 13g carbs and 19g protein. It's going to be hard to stay under 30g carbs. It will mean no nuts or even 99% chocolate and lots of concentration and counting :0@

Which is why I probably won't do it but any ideas that will widen my rather limited repertoire of main courses and improve my fat/protein ratio are gratefully received. And wow, avocado and eggs, are they scrambled?

Generally I have a small avocado with fresh lemon juice first, then 2 soft boiled eggs with a little iodised salt, and for a bit of zappy luxury 3 squares of 99% chocolate with my coffee and cream. Keeps me going for hours usually :0)

@Loversghost, What many people aren't aware of is that what is ketogenic low carb (which is what most people mean by Low Carb) varies entirely on your body size because big people have a lot more blood than small people and hence they end up with a lower concentration of glucose in their blood eating the same amount of carb.

This is something that people knowledgeable about diabetes know but which never makes it into most of the diet books which are almost exclusively written by doctors who know squat about blood sugar. Even many of the bestselling authors who write books that chatter about blood sugar fall into this category.

So a 150 lb woman needs half the glucose that a 300 lb man needs to achieve the identical blood sugar level when both people have the identical insulin sensitivity.

What this means, then, is that the eating level at which a person goes into a ketogenic state varies greatly with their size. A smaller woman might stop being in a ketogenic state eating at 75 g a day of carb, while that 300 lb man is ketogenic up to as much as 120 g.

I found that 60 g was the sweet spot for me at 145 lbs. You can tell where you are exiting a ketogenic state as you will suddenly put on a bunch of water when you eat enough carbs to put you over that ketogenic boundary. For me, there was a level somewhere in the 70s where if I ate just a bit more carb suddenly I gained three lbs. If I dropped below that boundary a day or so later, I was peeing my brains out for hours. In order to avoid that very unpleasant see-saw, I try to stay either way over or way under that boundary.

When I fast, I noticed that I hit that ketogenic boundary in the evening and would start peeing. And of course I'd gain back a few pounds after a day of eating non-fast, too.

I am thinking that it is the continual going up and down over that boundary that might be causing me the problems I'm having now with carb cravings and weight gain.

Even if 30% of calories from carbs is where many low carbers end up, I think that a fair comparison of low-fat vs low-carb should actually use a low carb diet? And if they choose to use moderate carbs (30%) on the basis that long-term that's what low carbers eat then they should also use the fat level that most low-fat dieters end up eating which is a good deal higher than 7%, so it is still an inappropriate diet comparison whichever way you cut it!

The short version of my extended comment below is that I wonder if it would be more acceptable if the researchers had found a trial arm signifier other than LC with its usual connotation of LC to describe this (NB, the title was Is a Calorie a Calorie? Metabolic Fat Balance Following Selective Isocaloric Restriction of Dietary Carbohydrate Vs. Fat in Obese Adults and in the text they use LC/LF to describe the trial arms which seems reasonable)? Plus, after a look through the numbers, if I were testing the hypothesis for which they were funded, I'm not sure that I could change the design in a helpful way and still test this hypothesis.
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To be clear, that 30% carbs wasn't an explanation that the authors offered but a side note of mine that was a related observation. The energy restricted part of the study was approx. 2000 kcals per day so 30% was approx. 150g of carbs: a lot more than you or I would eat but not outrageous for a LC assessment over that time period.

[I deleted another side note.]

eucaloric baseline diet (50% carbohydrate, 35 % fat, 15% protein) for 5 days followed by random assignment to 6 days of a 30% reduced energy diet achieved solely by restriction of either dietary fat (LF) or carbohydrate (LC)

So, afaict, for the trial design - the researchers premise was to reduce 30% of the overall energy intake from solely one macronutrient: either carbs or fat because the absolute amount of protein remains the same in the eucaloric and the 2 energy restriction arms (it's just a different percentage because of the manipulation of the other macronutrients). Based on their participants, this worked out at needing to eliminate approx. 800kcals which is 200g of carbs or 89g of fat. It wasn't feasible to omit more carbs in this trial design, that would have been more calories and there was a point at which that wouldn't have been possible for the low fat arm. If they'd assessed 50g of carbs in the LC arm, they'd have needed to cut an additional 400kcals from the overall energy reduced diet which wouldn't work for the LF arm because there were only 140kcals from fat in that arm with 7% (leaving aside the issue that they'd have been cutting 1200kcals which would be a 44% energy reduction and may well have had confounding physiological consequences).

In the eucaloric diet, and both of the trial arms, there were 420 calories from the protein. The approx. 2300/1580 other calories were made up carbs and fat, and in their respective trials, 800kcals had to be cut from either carbs or fat but, in the baseline diet (very close to a typical SAD), only 952kcals came from fat.

Given the near impossibility of designing a completely fat free diet and the then difficulty of the number of calories to be excised from the diet this strikes me as a reasonable design. Because, otherwise, they'd have had to opt for a 44% energy restriction in order to accommodate a similar reduction in calories in both carbs and fat. Yes, they could have made the energy restriction less to reach a point of equilibrium but then the changes in fat oxidation would have been negligible and there could be no effect size.

I have no idea why the scientists observed such a difference in fat oxidation rates: it might be interesting if they have some useful discussion of this, if/when this is written up for a journal rather than presented at a conference. It's interesting to note that the data from this may well have some interesting correspondences/differences wrt the same investigator's research into the effect of very low carbohydrate diet and energy expenditure (trial diet is 5% Carbohydrate, 15% Protein, 80% Fat).
https://clinicaltrials.gov/ct2/show/NCT01967563

[carorees]

I guess my complaint then is as you say @SSure that they call it low carb because the media are reporting that a low fat diet is better for burning fat than a low carb diet and this could cause people to get back on the low fat bandwagon and end up omitting essential nutrients (fats) while replacing them with nutrient free carbs.

this could cause people to get back on the low fat bandwagon and end up omitting essential nutrients (fats) while replacing them with nutrient free carbs.

Agreed that unnuanced media coverage is a major annoyance, particularly if it doesn't stress that that study is small and the results as yet only presented at a conference (the conversion rate to journal publications isn't fabulous). I don't know why health editors are so fond of polarisation of issues like this or over-reporting the relevance of work with so many limitations on its contribution to Public Health.

That said, altho' the other trial has its usual irritations and limitations (male participants, lots of exclusions), I will be interested to see the outcome of the very low carb (5%) study and energy expenditure.