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”:

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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.

Action on Sugar, Salt, Saturated Fat, Advertising and Supermarket Layout

“Campaign group” Action on Sugar yesterday launched their Childhood Obesity Action Plan, as requested by Jeremy Hunt MP and having read it I am again confused, baffled and befuddled, in fact nearly as much it seems, as they are.

I highlighted the many obvious problems with the Action on Sugar campaign previously noting their narrow focus and failure to acknowledge obesity as a multifaceted issue. I also more recently pointed out that their campaign had singled out sugar as uniquely damaging while espousing the virtues of fat and that this was a bad idea.

It doesn’t take a genius to work out that an obsessive focus on a single macronutrient (fat) is one of the reasons that we are where we are today, and that claims that reducing added sugar alone in processed food would solve the obesity crisis are ridiculous.

It seems however that something, somewhere has changed.

The Childhood Obesity Action Plan produced by Action on Sugar finally acknowledges that there are wider issues than just sugar reduction and that a range of measures will be required. Its not exactly a step change, the suggested measures are impractical and they still seems determined to blame the food industry for everything, but its an improvement of sorts.

However if you read the detail of the action plan you might raise an eyebrow – as unfeasibly high as Roger Moore during the 1980’s – at some of the contents.

Take Action 4 for example

Fat is a major source of calorie intake; we propose an incremental fat reduction programme similar to the salt and sugar reduction programme, to reduce fat by 15% by 2020 in all products.

Hallelujah!

Its taken them nearly six months to realise that calorie dense foods containing fat – which has about twice the calories of sugar – also need to be considered if you are to offer a joined up solution to obesity. Yes the suggest reduction constitutes only roughly 30kcal/day for 11-18 year olds but why did no one realise this for so long?

Even more surprising however is the rationale for targeting reductions in saturated fat

This should particularly focus on saturated fat, as this is the major factor controlling cholesterol levels (which is the third cause of death globally, through the vascular disease it causes, which leads to both strokes and heart attacks and peripheral vascular disease

Surprising because Action on Sugars Science Director Aseem Malhotra is the very person who wrote an article in the BMJ expressly refuting each and every statement in this rationale.

Does the Science Director not set the campaigns approach based upon the consensus view of the evidence? Has he had an epiphany since last year? How are decisions taken at Action on Sugar: A coin toss? The direction of the wind? A spur of the moment decision by the author of the press release?

Does anyone really think that Action on Sugar – now seemingly Action on Sugar, Salt, Saturated Fat, Advertising and Supermarket Layout – can come up with a coherent joined up solution to obesity when their very name shows how little they understand the issues, and they have a science director who doesn’t even subscribe to the views they promote?

 

 

The BMJ withdraw “incorrect figure” on statin side effects

The BMJ today took the step of withdrawing statements about statins

…suggesting that adverse events occur in 18-20% of patients

These statements in two articles published last October in the BMJ – one by John Abramson and colleagues focusing on new proposals to extend the routine use of statins to people at low risk of cardiovascular disease, and one by Dr Aseem Malhotra which repeated the figure – have been withdrawn because they

….exaggerated concerns over side effects.

Now I should firstly acknowledge that I agree that there is an entirely valid debate to be had about the wider use of statins for primary prevention and, that there are valid concerns that serious adverse effect data has not been fully disclosed in the manner which would satisfy all of the critics. The issues around statins are highly complex, and while there are many who can seem to approach these matters in a balanced reasonable manner there any many who are blind to evidence, or incapable of a disinterested evaluation of both sides of the argument.

No-one epitomises the myopic, black and white thinking about statins better than Zoe Harcombe – who today excelled herself – making spurious claims and attempting to deflect attention away from these headlines without acknowledging any errors had been made.

This is so serious – barely days after Australian dissent was silenced, UK freedom/truth is under attack 😦

Perhaps Zoe is reading a different BMJ editorial to me but I just don’t understand how this could be considered an attack on freedom or truth. A claim was made. The claim was queried. The authors responded. The claim was investigated by the BMJ. The writer of cited paper (Zhang) confirmed the authors incorrect interpretation. The authors fully co-operated and a retraction was made by the authors and BMJ. Its not complicated! Am I missing something?

This is so serious…[…]….The CTT won’t release Serious Adverse Effect data so how can we know?

The simple answer is that until –  or indeed if – that data is released we cannot know for sure about serious adverse effects. But that isn’t a good argument for not retracting a claim we now know is incorrect, is it?

This is the official BMJ article. The BMJ was alerted by Rory Collins – the top dog who refuses to share the SAE info

This is certainly true, but Zoe neglects to mention that other rapid responses had also queried the figure. Also, the source and motivation for the complaint is largely an irrelevant distraction because it was found by the BMJ, and willingly conceded by the authors to be an entirely valid one.

Not content with that Zoe tweeted the  BMJ editor Fiona Goodlee with

Will this panel have the power to force CTT to release the SAE data on statins that they refuse to disclose?

Yes Zoe – I’m sure a panel set up specifically to decided whether retraction of the two articles in full – as opposed to the specific statement in question – is justified, will spend a lot of time meddling in things totally outside their remit.

If you go back to one of the original rapid responses to Dr Aseem Malhotra which challenged his claim, you will find some now prophetic words from Chris Lawson which I think sum up my feelings on this issue nicely

The saturated fat hypothesis needs challenging, the effectiveness of statins as a large-population intervention needs challenging, and pharmaceutical company data needs challenging, but not like this

Amen to that.

Action on Sugar: A spoon full of evidence would help the medicine go down

Hidden Sugar or Total Sugar?

Action on Sugar launched yesterday, and ignoring the awful hyperbole which accompanied it I thought it was worth looking at what they are actually proposing in detail because the press release poses more questions than it answers. Fresh from ‘dealing’ with salt CASH state

A similar programme can be developed to gradually reduce the amount of added sugar with no substitution in food and soft drinks by setting targets for all foods and soft drinks where sugar has been added.

They published a high street food ‘Survey’ to illustrate this. I say survey but its actually a very small list, cherry picked to including some extreme examples of foods which by their nature and formulation may have high sugar levels. Does it really take over a dozen Professors and Doctors to point out that Frosties Coca-a-cola, Pepsi and Mars contain a lot of sugar?

Also if Action on Sugar are aiming to highlight the issue of unnecessary added sugars why on earth have they chose to illustrate it using the figures for total sugar content?  Probably because they have jumped the gun and set targets for “added sugar”  despite food labelling being inadequate to monitor such targets.

There are also practical issues can something made mainly of sugar contain “added sugar”? Should there be an arbitrary decision on what is necessary, who would decide this?

Well Action on Sugars proposals go much further than targeting hidden sugar in pasta sauce, as this article shows they also want confectionary and high sugar items to meet an overall 20-30% reduction target as well. This is despite the fact that these are products well know by consumers to be high in sugar, they are clearly labelled as such and the prevailing advice is to consume these in moderation.

Finally why is it so important to remove rather than to substitute? If the ultimate aim is to reduce calories why preclude for example, the use of artificial sweeteners on day one?

The Numbers Don’t Add Up

Action On Sugar has calculated that a 20 to 30% reduction in sugar added by the food industry which, given a reasonable timeframe (3-5 years) is easily achievable, would result in a reduction in calorie intake of approximately 100kcal/day and more in those people who are particularly prone to obesity.

Its good to know that a bunch of academics have deemed that reformulating every food and drink product in the UK containing added sugar is easily achievable within 3-5 years from their ivory towers. If they get their way I may retrain as a food scientist because there will certainly be a lot of work to go round. Monitoring compliance of such major changes would I imagine be equally easy and cheap.

This reduction in calorie intake is predicted to reverse or halt the obesity epidemic

For such major change the outcomes appears uncertain. Reverse or halt?

Sarcasm aside, its worth thinking about what these figures actually mean in practice. Using Sucrose (table sugar) as an example to achieve a 100 kcal per day reduction this would require a reduction in the consumption of added sugar of approximately 25g/day. Working backwards using their assumption that this can be generated by a 20-30% reduction at source we can see that Action on Sugar believe that the average person unwittingly consumes 86-129g of added sugar per day in processed food.

Is this realistic? We can get an idea from the National Diet & Nutrition Survey (NDNS) because this has survey data on Non Milk Extrinsic Sugars (NMES) – basically all the added sugar, honey, syrup and fruit juices in the diet. Although these figures are based on a small survey (and probably include a degree of under reporting) it becomes clear that there are major differences in the NMES intake by gender and age group, and only one group (males aged 11-18) are likely to come anywhere near achieving a 100kcal/day saving based on a 30% reduction in total NMES.

[Edit: Please see additional note below which provides another source of UK data on NMES].

I say total NMES because these figures I mention would make an underlying assumption that all added sugar in the diet comes in the form of ‘hidden sugar’ which we eat unwittingly in processed food and which can be removed without anyone noticing. What about the added sugar people knowingly choose to consume? There is no way of controlling this – I like a Tunnocks Caramel and a drizzle of honey on my Weetabix after all. What about sugar people add to hot drinks themselves?

In simple terms, reducing the sugar in soup or pasta at source cannot stop people eating too many Mars Bars, even if Action on Sugar got their way and they were made with 20-30% less sugar.

The failure to acknowledge obesity as multi-faceted issue by this group which also requires behavioural change and the insistence on this being as simple as cutting supply is staggeringly out of touch.

Errors, Misinformation and Poor Logic

There are a lot of errors, obvious misinformation and poor logic in the press release. While these are not significant in themselves they are indicative of people with shoddy reasoning

No other mammal eats added sugar…

Totally irrelevant.

I hadn’t ever considered whether other mammals eat added sugar in their diet before, probably because most of them are yet to invent processed food. If however they mean no mammal eats sugar they are quite wrong: bears, racoons are opportunist feeders who will undoubtedly exploit calorie rich food sources like honey when available. Eating sugar is not a unique human activity.

…and there is no requirement for added sugar in the human diet.

Firstly, its not required in the sense that you can choose what to eat. The real question though is whether it is harmful and if so in what amounts.

This sugar is a totally unnecessary source of calories…

Again meaningless assertion about necessity without any context.

….gives no feeling of fullness…

Good god Milky Way’s USP was a lie – all sugary snacks can be eaten without ruining your appetite!!

I’m joking of course, this statement which Dr Aseem Malhotra made repeatedly yesterday is blatantly false (sugar does have a satiating effect however small) and is one good example of why appointing him as Science Director when he has no experience in the field and has published no research is a really bad idea.

Where is the research and evidence?

The above is not the only issue with evidence, Malhotra again…

… and is acknowledged to be a major factor in causing obesity and diabetes both in the UK and worldwide.

You read that right. Dr Malhotra appears to be claiming a causal relationship between sugar and type 2 diabetes. Yes it is associated with obesity and this is a risk factor in type 2 diabetes but no direct causal relationship has been established. I think its telling that Action on Sugar have sections on their temporary website for ‘press’ but nothing for ‘research’ and ‘evidence’. Is this the standard of evidence we can expect?

Conclusion

These appear to be poorly thought out proposals which would have uncertain benefits and the campaign seems to be more about misinformation and winning hearts and minds via the daybreak sofa than driving change through robust evidence. I will be putting some of these issues to Action on Sugar and will add their response, if any below.

In the meantime, ask them for evidence yourself.

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Update 12/01/2014

Via twitter another source of data for UK NMES was provided (big thanks to Phil Thompson @UKLowCarb) which is the Department for Environment, Food & Rural Affairs Family Food Datasets. These are presented as averages per person per day and helpfully include both household and eating out energy and nutrient intakes.

Apart from showing a general downward trend in NMES from 92g/person/day in 2001-2 to 77g/person/day in 2012 these would also suggest that a 20-30% reduction is unlikely to provide a 100kcal/person/day reduction in calories. This may explain why one day after launching with these numbers in their press release, Dr Aseem Malholtra is now referring to  a 40% reduction to achieve this target.