Fact Check: Eat Fat, Cut The Carbs and Avoid Snacking To Reverse Obesity and Type 2 Diabetes (Section 1 & 9)

The joint report Eat Fat, Cut The Carbs and Avoid Snacking To Reverse Obesity and Type 2 Diabetes published by selected members of the National Obesity Forum (NOF) and Public Health Collaboration (PHC) has caused quite a stir. A number of the NOF board have now resigned with some distancing themselves entirely from the report and the The Royal Society for Public Health went as far as labelling it a “muddled manifesto of sweeping statements, generalisations and speculation”. Ouch.FireShot Screen Capture #735 - '' - phcuk_org_wp-content_uploads_2016_0.png

I thought it would be worth doing a quick fact check of some of the claims made in this report. To avoid the inevitable strawman criticism which will come my way, I am not asserting that the overall message of the report is right or wrong, nor am I advocating for a particular diet in this post.

What I am saying however is that if you wish to make a coherent argument it should be i) internally consistent and ii) supported by citations which say what you claim they say.

Comments are enabled so let me know if I have made any errors myself, or if you spot anything I have missed. I’ll be happy to correct.

Section 1. Eating Fat Does Not Make You Fat

“Evidence from multiple randomised controlled trials have revealed that a higher fat, lower carbohydrate diet is superior to a low-fat diet for weight loss and cardiovascular disease risk reduction [8, 9]”

The first reference [8] is a meta-analysis by Sackner-Bernstein et al. The cited paper does indeed conclude that Low-Carb diets are superior for weight loss and reducing markers of CVD risk. However the nuance that their superiority is “numerically modest” is excluded from the NOF/PHC report:

superiority

The second reference [9] also supports that claim. A minor gripe here though, if we are making the case about multiple trials showing benefit why is this particular individual Randomised Controlled Trial (RCT) Bazzanno et al  worthy of note when there are meta-analyses available?

“An exhaustive analysis of 53 randomised controlled trials involving 68,128 participants conducted by the Harvard School of Public Health concluded“ when compared with dietary interventions of similar intensity, evidence from randomised controlled trials does not support low fat diets over other dietary interventions for long term weight loss. In weight loss trials, higher fat weight loss interventions led to significantly greater weight loss than low fat interventions.”

No citation is provided for this claim. Sloppy, but not a big problem as it’s a recent and relatively easy to find paper with the information provided: “Effect of low-fat diet interventions versus other diet interventions on long-term weight change in adults: a systematic review and meta-analysis” by Tobias et al. The quote cited does indeed appear in this meta-analysis.

Again, a minor gripe but the Bazzano et el paper cited by the NOF/PHC separately as reference [9] is one of the papers considered within this meta-analysis, so there is a minor element of double counting of evidence here. Its hardly significant, but it is indicative that a systematic approach has not been taken by NOF/PHC in term of identifying and presenting the body of evidence.

bazzano

One other point which we will come back to is that this meta-analysis considers not just low-carb, high fat and low-fat dietary comparisons – where data is available – but also separates the trials into studies aimed at weight loss (with and without weight loss goals) and weight maintenance.

Things now begin to go downhill as they focus on one particular trial:

“Furthermore the Women’s Health Initiative was the largest randomised controlled diet trial ever performed”.

Its not clear why the NOF/PHC feel that this RCT trial in particular needs to be discussed further, especially when it was another RCT which was included within the previously cited meta-analysis by Tobias et al. 

48,835 post-menopausal women were randomised to either their usual diet or a low-fat, calorie reduced diet with increased exercise with the hypothesis that this would reduce cardiovascular disease.

Inaccurate in one important aspect. According to the citation it was a dietary modification trial in which participants were counselled to change the composition of their diet but not to reduce energy intake (i.e. there were no weight loss goals):

FireShot Screen Capture #054 - 'JAMA Network I JAMA I Low-Fat Dietary Pattern and Risk of Cardiovascular Disease_  The Women's Health Initiative Randomized Controlled Dietary Modification Trial' - jama_jamanetw

“The intervention achieved an 8.2% energy decrease in total fat intake and a 2.9% energy decrease in saturated fat intake, but did not reduce risk of CHD or stroke.[10]”

Correct.

While not specifically a weight loss trial, nevertheless, the reduction in dietary fat and total daily calories (361 calories/day reduction) also failed to produce any significant weight loss over the duration of the study.

It was not a weight loss trial, it was a weight maintenance trial.

The reduction in daily calories does not appear in the cited paper anywhere. There is however a separate paper from the Women’s Health Initiative trial titled “Low-Fat Dietary Pattern and Weight Change Over 7 Years” so it looks like a citation error. The reduction in calories is taken from Table 2 of this paper and it represents the final nutrient intake (baseline minus follow-up) estimated by Food Frequency Questionnaire (FFQ):

FFQ

It is extremely misleading to take a figure from the follow-up FFQ  and present this as if this was a calorie deficit which was achieved and maintained for the duration of the trial (“361 calories/day reduction”). It gives a false impression that large and sustained energy deficit was achieved, yet significant weight loss was not. We also don’t know, of course if participants were at energy balance at baseline.

It is even more misleading when you consider that data obtained from FFQs are well known to have weaknesses and that the authors of the paper explicitly highlights this issue to prevent misinterpretation:

FireShot Screen Capture #057 - 'JAMA Network I JAMA I Low-Fat Dietary Pattern and Weight Change Over 7 Years_  The Women's Health Initiative Dietary Modification Trial' - jama_jamanetwork_com_article_aspx_artic

This isn’t the first time the PHCUK have misused self reported data without acknowledging the uncertainty in the measurement – even when the dangers of this are explicitly stated by their source.

As for the claim that Women Health Initiative trial failed to “produce any significant weight loss over the duration of the study” I’ll leave you to decide if that claim is true:

figure 2

figure 1key

(But the answer is: no, it’s entirely untrue).

As an aside, the dietary pattern and weight change paper is well worth reading in full because it also includes statements like the one below which are, ahem…let’s say inconvenient to the pro-fat argument that the NOF/PHC are trying to craft:

FAT

“This rejected the notion that the low-fat diet is either beneficial for cardiovascular disease or weight loss.”

I think the NOF/PHC have a problem here with the consistency of their argument. It’s rather strange to put forward the argument that low fat diets are “not beneficial for cardiovascular disease or weight loss” based solely on one (albeit large) RCT when they have already cited other evidence which tends to refutes that claim.

Remember the Sackner-Bernstein et al meta-analysis cited at the start of this section of the NOF/PHC  report which they used to argue for the superiority of low-carb diets over low-fat diets? It concludes:

PLus one

What about the Tobias et al meta-analysis – which includes the WHI study – and looks at weight loss and weight maintenance? It shows that the low fat diet is superior to the standard diet for weight loss (with and without goals) and for weight maintenance, and that they were broadly not significantly different from higher fat diets unless they also restrict carbohydrate.

“We recommend that guidelines for weight loss for the UK should include an ad libitum low refined carbohydrate and a high healthy high fat diet (i.e non-processed foods or “real” foods) as an acceptable, effective and safe approach for preventing weight gain and aiding weight loss.”

It is unclear which data is being used to support the use of low refined carbohydrate diets for long term weight maintenance. According to the Tobias et al meta-analysis cited by NOF/PHC “no long-term non-weight loss or weight maintenance trials compared low-fat with low-carbohydrate dietary interventions”:

FireShot Screen Capture #734 - '' - www_adipositas-stiftung_de_cms_images_stories_pdf_Effect_of_low-fat_diet_interventions_versus_other_diet_interventions_on_long-term_weight_change_in_adults_-__p.png

Section 9. Snacking will make you fat (Grandma was right!)

There have been two major changes in our dietary habits since the 1970s, prior to the onset of the obesity epidemic. The change to a high carbohydrate, low fat diet has been well documented and has played an important role in causing obesity.

Assertion and questionable language. The change to a high carbohydrate diet is causing, or is associated with increasing obesity? (Answer: the latter, if you care about not committing the post ergo propter hoc fallacy).

The other change, the increase in meal frequency plays an equal if not larger role and has been largely ignored. In the 1970s, the average number of eating opportunities was three – breakfast, lunch and dinner. Fast-forward to 2005 and that number has almost doubled. [40]

If I’ve understood this properly the position taken by the NOF/PHCuk is that obesity in the UK has been driven not by increasing calorie intake, but by an increase in insulin secretion caused by frequent high carbohydrate meals. The citation leads to this cross sectional study. The cited study does indeed confirm that frequency of eating opportunities has increased since the 1970’s, but in the USA.

If we accept that the UK and USA are broadly similar we are still left with a couple of issues before we accept the above argument: i) cross-sectional studies cannot show causation ii) the citation makes the case that the increase in eating opportunity in the USA also correlates with an increase in overall energy intake (i.e. not one of the two major changes to diet identified by the NOF/PHC):

FireShot Screen Capture #053 - 'Does hunger and satiety

To further developing the idea that meal frequency is one of the major factors in increasing obesity the following claim is made:

“Eating continuously from the moment we arise to the moment we go to sleep does not allow our body to digest and use some of the foods that we eat. The entire day becomes an opportunity to store food energy without a chance to burn it. Eating six times a day does not result in weight loss (41), but tends to increase overall consumption of food.”

The third sentence is interesting and the citation for this is “Increased meal frequency does not promote greater weight loss in subjects who were prescribed an 8-week equi-energetic energy-restricted diet” by Cameron et al. This is a small RCT (n=16) looking at the hypothesis that a high meal frequency (MF) might lead to a greater weight loss than that obtained with a low MF under conditions of similar energy restriction.

The absolute claim that “eating six meals a day does not result in weight loss” is directly contradicted by the citation. Over eight weeks participants in the high-MF group (3 meals/day and 3 snacks/day) did in fact lose weight:FireShot Screen Capture #050 - '' - www_researchgate_net_profile_EWeight loss is entirely unsurprising, since despite having six meals per day the protocols were designed to achieve an energy deficit in both low-MF and high-MF groups:

FireShot Screen Capture #052 - '' - www_researchgate_net_pr

The claim that six meals per day “tends to increase overall consumption of food” might be true, but due to the design of this study, which involved the participants actively trying to lose weight by adhering to a prescribed calorie deficit, it cannot support that claim.

Authorship and Peer Review

While initially the document was issued without any acknowledgement of authorship we now know via a statement on the NOF website that a large number of individuals were co-authors. Some of these have competing interests (e.g. David Haslam sits on the scientific advisory board for Atkins Nutritional, Sam Feltham has a diet book for sale based on the principles in this report) and for transparency these really should have been identified in a statement of competing interests.

It seems unusual that there was also an “expert panel” who “supported” the paper as well as “peer reviewing” it before publication? Where is the line drawn between support and co-authorship? – this isn’t at all clear.

Some of the people are listed as “co-author” and “peer reviewer” (is that even possible?) while others are clearly not experts – “Film maker and health activist”, “Best-selling author and health activist”. authorsreviewers

I think it would have been better to simply say the paper has not been externally peer reviewed and leave it at that.

Conclusion

Having reviewed a couple of sections of the report in detail and skimmed the remainder the bias within this document is plain to see and there are serious issues about the way this report was authored and checked.

There is little evidence that a systematic approach has been taken to identify and appraise relevant evidence to inform their claims and it relies quite heavily upon simple unreferenced assertion to make the case for higher fat diets.

The benefits of high fat and low-carb diets are presented in a way which would lead the casual reader to expect major benefits and superiority over alternatives, when in fact this is often shown to be marginal, or there is simply insufficient data to justify the conclusions drawn by NOF/PHC  (e.g. low-carb diets for weight maintenance).

It’s apparent that there is a sloppy approach to citations, and some of the claims made are just plain wrong. It’s baffling that this large cohort of co-authors and an equally large cohort of “peer reviewers” didn’t check the claims they were making sufficiently, or possess sufficient understanding/expertise or impartiality to interpret the data in a more even handed manner.

The NOF/PHC need to acknowledge and correct the obvious errors within this report.

Advertisements

The Public Health Collaboration UK: Wrong about energy intake

Yesterday saw the launch of a funding campaign on indiegogo to establish a new charity called the Public Health Collaboration UK.

Without wishing to pre-judge, this group of doctors and low carbohydrate diet proponents who aspire to:

……collaborate our efforts into one singular organisation to inform the public and empower the medical community on the science and solutions of health. 1

……seems to look suspiciously like a thinly disguised lobby group who’s activities will produce opinion papers which will – inevitably – be sexed up to the level of fact on the BBC Breakfast sofa and in press releases, by the media savvy members to promote their diet de jour.

So what are they claiming?

…….in the UK 25% of adults are obese, the highest prevalence in Europe, and type 2 diabetes has risen by 65% in the past 10 years with no sign of slowing down. Together they cost the NHS £16 billion a year and the UK economy at large £47 billion a year. 1

Strong start.

These perilous percentages and shocking statistics have presented themselves despite the fact that as a population we are closely following the dietary advice that is being recommended to us. 1

Forgive me just one argument from incredulity, but really? We’ve followed the guidelines closely? 

I’m going to need some evidence for that.

Based on the latest National Diet and Nutrition Survey published in 2014 by Public Health England, our total food consumption is on average 383 calories below the recommended……1

Jesus. They appear to have taken the data literally.

A quick skim through the National Diet and Nutrition Survey report itself reveals the following:

Dietary surveys are reliant on self-reported measures of food intake. Misreporting of food consumption, generally underreporting, in self-reported dietary methods is a well-documented issue. The under-reporting of energy intake (EI) is known to be an issue in past and current NDNS, as for all dietary surveys and studies. This is an important consideration when interpreting the findings from this survey.2

The energy and nutrient intakes presented in this report have not been adjusted to take account of underreporting 3 

It is not possible to extrapolate this estimate of underreporting to individual foods and nutrients because they may be affected differentially. 3

The report also discusses how the doubly labelled water technique was used to validate the figures for a sub set of the surveys and it highlighted potentially large discrepancies between reported energy intake (EI) and total energy expenditure (TEE):

In the NDNS RP, estimates of EI from the four-day diary were compared with measurements of total energy expenditure (TEE) using the DLW technique in a sub-sample of survey participants. The results of this analysis indicated that reported EI in adults aged 16 to 64 years was on average 34% lower than TEE measured by the DLW technique, 12% lower in children aged four to ten years, 26% lower in children aged 11 to 15 years, and 29% lower in adults aged 65 years and over.  3

In short, these figures might show trends or where intakes of certains aspects of diet are below recommended levels but they are not robust enough to conclude that the UK is getting more obese and (T2) diabetic despite eating less. And if you must use the data state the level of uncertainty in the data. I raised the issue on twitter with the collaboration of experts but none were willing to acknowledge or correct the erroneous claim on energy intake which does not bode well for a wannabe charity.

It is also quite surprising to see the collaboration citing this as evidence when Exit Door favourite Aseem Malhotra has previously stated on national television that this type of survey is:

….heavily flawed because it relies on personal reporting which we know classically under reports calories consumed….

I’m not detecting much of a collaborative effort here – did Aseem even read this before release, and if so – did he recognise the mammoth level of hypocrisy involved in putting his name to this?

The call for funding goes on make further broad, unsubstantiated ideologically driven claims without even attempting to evidence them:

…..the Eatwell plate and simple calorie restriction, that have been used for the past 20 years with no improvements in public health 1

All of which is irrelevant conjecture until you have completed the monumental first step of demonstrating that the population have been following the guidelines throughout this period (good luck with that one).

I sense entertainment lies ahead – it will be interesting to see who of the experts are willing to be a trustee of a charity which is already playing fast and loose with the evidence, and more interestingly one whose begging bowl approach to funding seems to places their dubious claims within the remit of the Advertising Standards Authority.


References

1 https://www.indiegogo.com/projects/public-health-collaboration#/

National Diet and Nutrition Survey Results from Years 1, 2, 3 and 4 (combined) of the Rolling Programme (2008/2009 – 2011/2012) p74 

National Diet and Nutrition Survey Results from Years 1, 2, 3 and 4 (combined) of the Rolling Programme (2008/2009 – 2011/2012) p75 

 

Nina Teicholz, Health Ministers and the Swedish “Government” Low-Carb Diet Guidelines

I’ve not yet got round to reading The Big Fat Surprise by investigative reporter Nina Teicholz, but her recent tweets in support of her thesis (the claim that the science says that a healthy diet includes large amount of fats from butter, meat and cheese) have become increasingly bizarre.

Here is an example:

Now, lets stop for a moment and think really hard about what she might be implying here.

Could it be that Teicholz knows in detail about the particular diets of these individuals (Maggie De Block, Belgium; Gabriel Wikström, Sweden and Gaetan Barrette, Quebec) and is implying that by observation alone we can see that one particular diet is the best for weight?

Even if that were true – and I can find no evidence to support the idea that Gabriel Wikström achieved or maintains his weight using LCHF – how does an uncontrolled observation based on three individuals with a multitude of other differences tell us anything about diet?

It also raises the ugly spectre of cherry picking – why were these particular members used as examples and not say the UK’s Jeremy Hunt, another country which hasn’t adopted low-carb dietary guidelines?

jeremy-hunt-wild-things

For the avoidance of confusion, Jeremy Hunt is the svelte chap on the left. No, the use of Health Ministers implies something else…….

Could it be then, that Teicholz is implying that you cannot be a health minister on merit, if your BMI isn’t acceptable?

Hmm, while there may be an element of offensive fat shaming involved, I think her further tweet eludes to her real meaning:

Teicholz seems to be implying that the health ministers are in some way the physical manifestation of the success of the dietary policies of the nations or province.

Aside from the fundamental daftness of this idea, and the fact that the Swedish Council on Health Technology Assessment was only written just over a year ago (thus having limited time to effect the health of an entire nation), she gets fundamental facts about it totally and utterly wrong.

It is not a Government Report or set of consumer guidelines, it is a Swedish Council on Health Technology Assessment.  This report has been misrepresented so much that Swedish National Food Agency even took the step of clarifying this matter:

Sweden does not have any guidelines on low-carb-high-fat diets. The information that Sweden has guidelines on low-carb-high-fat diets is based on incorrect information circulating on the Internet.

Has this investigative reporter heard of Google? Did she not think it weird that no-one has actually produced this set of paradigm shifting guidelines?

Also I cannot see how the report itself can be interpreted by Teicholz, or anyone to mean the Swedish Government is the first to:

…formally ditch the low-fat diet.”

I mean even with just the press release in English it seems pretty clear to me that the report states that Low Carb is the best for short term weight loss (<6 months), but is one of a number of comparable options for longer term weight loss which includes low fat and Mediterranean diets:-

In the short term (six months), advice on strict or moderate low carbohydrate diets is a more effective means of achieving weight loss than advice on low fat diets. In the long term, there are no differences in the effect on weight loss between advice on strict and moderate low carbohydrate diets, low fat diets, high protein diets, Mediterranean diets, diets aimed at achieving a low glycaemic load or diets containing a high percentage of monounsaturated fats.

Further the only diet for weight maintenance with sufficient evidence is low fat, in preference to either LC or Mediterranean:

Maintaining reduced weight. When obese individuals have lost weight, they can maintain their weight more effectively with advice on low fat diets with a low glycaemic index and/or high protein content rather than low fat diets with a high glycaemic index and/or low protein content. There is no data available to assess whether advice on low carbohydrate diets and Mediterranean diets, for example, is effective to prevent weight increase after weight loss.

For someone who is an investigative reporter there is a staggering amount of poor reasoning and a lack of fact checking here.

Its time for the zombie fact about the Swedish Low-Carb guidelines to be put back in its grave for good, and Nina can start that process with a retraction of what is clearly misinformation.

Updated 31/10/2014

In response to comments from Jacques Rousseau on twitter (do read his excellent blog post here) Nina Teicholz’s claims:

Firstly on the issue of policy, Health Technology assessments are authored by the independent Swedish SBU and the reports produced:

…could, for example, be an important source of information for other decision-making authorities, such as the National Board of Health and Welfare, the Medical Products Agency and the Dental and Pharmaceutical Benefits Agency. Professional associations of health care personnel, such as doctors, nurses and dentists, can use SBU reports as a basis in preparing their own guidelines. An SBU report can also be used at an individual health centre or clinic to provide guidance on the possible benefits for patients of introducing, prioritising or, in some cases, excluding methods.

Note the use of the words could, and can. The purpose of a HTA is to act as an independent guide to decision making. Yes the recommendations can be adopted within separate guidelines (or used to devolve decision making all the way down to individual doctors and nurses) but it is not and never will be a Government Policy. If Sweden had translated the HTA into guidelines rejecting the LF diet, where are they?

This are, of course moot points, because Nina Teicholz totally misrepresents the content of the report.

The idea that the authors were biased to keep in line with established wisdom is laughable – I mean just read the report itself, each decision was graded based upon specific evidence presented by the SBU and the evidence for LCHF was simply lacking, or absent in many area. If you don’t believe me feel free to read a translated summary here.

Faced with this refusal to amend her false claim I issued a simple challenge which would take no more than 10 minutes on google:

..and further offered to set the record straight if I am wrong:

After a number of requests Nina Teicholz simply blocked me on twitter.

 

The Action on Sugar Drinking Game*

With the SACN Working Group on Carbohydrates about to report on sugar, and the continued efforts of Action on Sugar to ensure that it is featured in every news report, debate and jerry-built opinion piece in the newspapers I thought we may as well have some fun from it.

Accordingly I am proud to present the Action on Sugar Drinking Game. The game can be played with the alcoholic beverage of your choice* or perhaps more aptly, Coca-Cola.


Take 1 finger of drink when any representative of Action on Sugar says:

  • “obesity”
  • “refined carbohydrate”
  • “no nutritional value”
  • “sugar sweetened beverage”
  • “sugar tax”

Take 2 fingers of drink for:-

  • “big food”
  • “is the new tobacco”
  • “legislate”
  • “increased risk of type 2 diabetes”

Take 3 fingers of drink for:-

  • “cripple the NHS”
  • “study from Stamford”

Half a pint for:-

  • “energy you don’t want and don’t need”

Finish your drink whenever Dr Aseem Malhotra expresses his concern for ‘the children’.

 

*Drink responsibly kids.

Action on Sugar: Operation Sugar Tax

Having frightened the living shit out of the general public during the initial phase of their campaign which established the narrative that sugar is a granular health menace which hides in plain sight in pretty much everything produced by the food industry, Action on Sugar now enter phase II of their campaign – Operation Sugar Tax.

Operation Sugar Tax basically involves more of the same – a round of interviews, press releases, scaremongering – with the ultimate aim of lobbying for, and attempting to justifying a sugar tax as a nice easy solution to the multifactorial problem of obesity, which we can conveniently lay at the door of the food industry.

Action on Sugar have some very specific stated aims which do admittedly include pushing the Department for Health for legislative measures but it is also worth noting these two less confrontational aims which presumably, should be attempted first

To reach a consensus with the food manufacturers and suppliers that there is strong evidence that refined added sugar is a major cause of obesity and has other adverse health effects.

To persuade the food processors and suppliers to universally and gradually reduce the added sugar content of processed foods

I have no idea why Action on Sugar included these aims because they clearly have no intention of working with the food industry, like many public health campaigners their mind is already made up regardless of the evidence, and they see no need to use a carrot when a stick will do.

They could of course prove me wrong and confirm which food companies they have been attempting to ‘persuade’ and ‘reach a consensus’ with. I’d wager that since formation they haven’t met a single one.

This is of course a moot point because when your ‘Science Director’ is regularly making derogatory hyperbole riddled statements about the Food Industry mostly based on flawed science they are unlikely to even want to sit on the same sofa as him, let alone engage in reasonable debate about the issues.

 

Update 07/03/2014

Barely had the ink dried on this post when Malhotra was at it again in this Daily Mail article in which he again alienates the food industry and falls only slightly short of accusing the government and their advisors of being outright corrupt. I presume he thinks this is the best way for Action on Sugar to achieve the following stated aims

To conduct a Parliamentary campaign to ensure the Government and Department of Health take action, and that, if the food industry do not comply with the sugar targets, they will enact legislation or impose a added sugar tax

and

To ensure the body of scientific evidence about the dangers of excessive refined added sugar consumption becomes translated into policy by the Government and relevant professional organisations.

It looks like Action on Sugar will be going it alone.