The PHC Guidelines – A Critique

The Public Health Collaboration (PHC) is a fantastic idea. Rates of obesity are increasing and it’s clear that something needs to change in order to stem the tide. The problem? This has descended into a political style battle between two sides of the same the coin.

Politics

It seems we have long since lost faith in politics in this country. Reports and studies can be spun to fit a side’s agenda. Democracy is now a petulant battle between leaders perched upon ivory towers, each desperately trying to ‘connect’ with the electorate. Battles are not won with logic or reason. Battles are won through fear and discrediting the opposing argument.

PHC vs PHE

The impression given by the PHC is that they seem hell-bent on picking a fight with Public Health England (PHE) and current dietary advice. Challenging the status quo is a good thing. Science should always challenge. There are flaws in the current government guidelines and a number of evidence-based holes. We’ll discuss a few in a minute, but first, let’s acknowledge a big elephant in the room.

Emotive responses

The PHC have the politician thing down. They do a fantastic job at telling us what we want to hear. It’s our fault we’re overweight, it’s the government’s. Their guidelines are wrong. We’ve been deliberately misled by those in high office who seek to line their pockets with food industry payoffs. I mean animals are fed grains to fatten them up. Surely the government are feeding us grains to get fat too!

Government guidelines – what’s wrong?

“Current efforts have failed – the proof being that obesity levels are higher than they have ever been, and show no chance of reducing despite the best efforts of government and scientists.” Prof. David Haslam

Current efforts have failed, but can that really be blamed on the government guidelines? They’re certainly flawed. But how many people are actually following them? Randomised controlled trials seem to indicate that when they are followed, favourable health outcomes are seen (Reidlinger et al., 2015).

Eatwell plateAccuracy of reporting

If you believe that the population is consuming an average of 383 calories below the recommended daily amount and less than the recommended 35% of calories from fat, then you have a lot more faith in the government statistics than I do. Self-reporting of dietary intake is widely recognised to be inaccurate and subject to substantial under-reporting. The Energy Balance Working Group (Dhurandhar et al., 2015) go so far as to suggest that scientific and medical communities should discontinue their reliance these on methods.

PHC guidelines – any better?

I like many aspects of the PHC guidelines. Again, an emotive response based on the factor that it more closely resembles my diet versus the eat-well plate. Who doesn’t love a little confirmation bias? The main things I like…

  • It places greater emphasis on eating unprocessed foods
  • It better acknowledges the importance of protein
  • It doesn’t seek to limit foods based solely on fat and saturated fat content

PHC Contention#RealFoodRocks

I like the hashtag #RealFoodRocks. Granted, it’s a massively subjective and un-scientific term, but that’s the point. It’s designed to be an emotive and empowering statement. It’s a great message and a positive one at that. My problem is that they’ve pitched this as a ground-breaking, anti-establishment message. It’s not. What they’ve done is spun this in a better way the current guidelines. Fair play to them for doing so, I think it’s the right way to go.

Low carb is a viable approach

The government guidelines don’t seem acknowledge the fact that a low carbohydrate diet is a strategy that can work well if implemented sensibly. The PHC reports places a lot of emphasis upon a recent review by Mansoor et al. (2016), which suggested that rates low carbohydrate diets (20% of kcal) led to greater weight loss. However, the authors did also report increased LDL cholesterol with the low carbohydrate diets.

Low carb isn’t the only way either

In reality, low carbohydrate may be a better option for some. To say it’s better for all would not be correct. An American Medical Associated review (Johnston et al., 2014) demonstrated no difference between the effectiveness of low carbohydrate and low fat diets for weight loss. Even where individuals demonstrate insulin resistance, low carbohydrate and low fat interventions appear equally effective in achieving weight loss and improving symptoms of metabolic syndrome (Gardner et al., 2016).

Saturated fat – not all bad?

I like that are challenging the idea that foods should be limited solely because of saturated fat. Recent re-evaluation of the Minnesota Coronary Experiment from the 1970’s, upon which many recommendations were subsequently based, has drawn into question the purported adverse health effects of saturated fat. Upon re-examining the data, Ramsden et al. (2016) reported that replacing saturated fat in the diet with linoleic acid (i.e. vegetable oils) effectively lowers serum cholesterol but does not support the hypothesis that this translates to a lower risk of death from coronary heart disease or all-cause mortality. Previous meta-analysis, such as the often cited Siri-Tarino et al. (2010), reached similar conclusions.

Saturated fat – are there still links with CV events?

The above is all very well. However, precede with caution. The reduction of saturated fat in the diet is associated with “small but potentially important” reduction in cardiovascular risk according to a recent Cochrane review (Hooper et al., 2015). The report demonstrated that a reduction of saturated fat intake (to below <10% kcal recommendation) was associated with a reduction in the risk of cardiovascular events by 17% (95%CI: 4-28%).

Full-fat dairy

Another problem I have with government guidelines is the advice to choose reduced fat sources of dairy. Reviews associated full fat dairy consumption with reduction in adiposity (Kratz et al., 2013) and prevalence of metabolic syndrome Drehmer et al. (2016).

Free-reign on fat

Big fat lieThe fact that fat is not bad for us does not mean we can eat as much as we like. Sadly, this is not how the media have reported things. Even more worryingly, the PHC do not appear to have taken issue with such media reports. They seem to see these articles as a badge of honour

Cholesterol isn’t all bad

The cholesterol issue has been a contentious one for a while. More sparks are certainly flying in the light of a new review suggesting that LDL (aka ‘bad’) cholesterol may be inversely associated with mortality (Ravnskov et al., 2016). NB – we’ll be featuring this the next Research Review! Also, the Centre for Evidence Based Medicine have posted a critique of the studies methods here.

Cholesterol might not be all good though

A newly published meta-analysis (Li et al., 2016) suggests that high- (394 mg/d) vs low-cholesterol (138 mg/d) consumption is associated with a 29% increase (95%CI: 6-56%) in the risk of breast cancer. A dose-response relationship between dietary cholesterol and breast cancer became statistically significant when the cholesterol intake was greater than 370 mg/d (approx. 1 egg).

High-fat and diabetes – the good

The PHC are pretty vocal about the use of high fat diets in the management of type II diabetes. Indeed, reviews do tend to suggest a benefit to low carbohydrate, high protein diets vs control diets (Ajala et al., 2013). It’s not all one-way traffic through…

High fat and diabetes – the bad

von Frankenberg et al. (2015) reported that a four-week high-fat diet (55% fat, 25% saturated fat, 27% carbohydrate) decreased insulin sensitivity. Conversely, a low-fat diet (20% fat, 8% saturated fat, 62% carbohydrate) did not. Changes in VLDL cholesterol (often referred to as the ‘bad’) negatively correlated (r = 0.71-77; P < 0.02) with changes in insulin sensitivity – VLDL went up, insulin sensitivity got worse. This study isn’t a one-off. For example, low carbohydrate and high fat diets have been associated with higher HbA1C concentrations by Shadman et al. (2013).

I love the quote from the recent Williams and Wu (2016) review, “insulin is a hormone of caloric prosperity.” Finding a way to combat excess energy intake is the most important factor and this can be achieved using a number of different approaches.

Demonisation of sugar

SugarAs much as the Western diet is full of sugary junk food with no nutritional value, does the research really support the demonisation of sugar? It doesn’t appear so. Meta-analyses do not support a unique association between sugar and obesity, metabolic syndrome, diabetes, risk factors for heart disease, or non-alcoholic fatty liver disease (Rippe & Angelopoulos, 2015).

Moving forward

It’s good that the PHC are challenging the status quo. Hopefully the pressure they apply will lead into the evolution of dietary guidelines that are better matched with the evidence base. However, this is missing the point. We’re in a state not because of guidelines but in spite of them. We need to find ways to change the psychologies and behaviours that surround eating. People instinctively know what are ‘healthy’ and ‘unhealthy’ foods, even if controversies such as red meat and fat content may cloud things slightly. Progress needs to come through working together and tackling these issues. Not by having pointless debates on BBC Breakfast.

 

References
Ajala O, English P, Pinkney J. Systematic review and meta-analysis of different dietary approaches to the management of type 2 diabetes. American Journal of Clinical Nutrition. 2013: 97: 505-516.
Dhurandhar NV, Schoeller D, Brown AW, Heymsfield SB, Thomas D, Sørensen TIA, Speakman JR, Jeansonne M, Allison DB, Group EBMW. Energy balance measurement: when something is not better than nothing. International Journal of Obesity. 2015: 39: 1109-1113.
Drehmer M, Pereira MA, Schmidt MI, Alvim S, Lotufo PA, Luft VC, Duncan BB. Total and full-fat, but not low-fat, dairy product intakes are inversely associated with metabolic syndrome in adults. The Journal of Nutrition. 2016: 146: 81-89.
Gardner CD, Offringa LC, Hartle JC, Kapphahn K, Cherin R. Weight loss on low-fat vs. low-carbohydrate diets by insulin resistance status among overweight adults and adults with obesity: A randomized pilot trial. Obesity. 2016: 24: 79-86.
Hooper L, Martin N, Abdelhamid A, Davey Smith G. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database of Systematic Reviews. 2015: 6: CD011737.
Johnston BC, Kanters S, Bandayrel K, Wu P, Naji F, Siemieniuk RA, Ball GD, Busse JW, Thorlund K, Guyatt G, Jansen JP, Mills EJ. Comparison of weight loss among named diet programs in overweight and obese adults: a meta-analysis. Journal of the American Medical Association. 2014: 312: 923-933.
Kratz M, Baars T, Guyenet S. The relationship between high-fat dairy consumption and obesity, cardiovascular, and metabolic disease. European Journal of Nutrition. 2013: 52: 1-24.
Li C, Yang L, Zhang D, Jiang W. Systematic review and meta-analysis suggest that dietary cholesterol intake increases risk of breast cancer. Nutrition Research. 2016: 36: 627-635.
Mansoor N, Vinknes KJ, Veierød MB, Retterstøl K. Effects of low-carbohydrate diets v. low-fat diets on body weight and cardiovascular risk factors: a meta-analysis of randomised controlled trials. British Journal of Nutrition. 2016: 115: 466-479.
Ramsden CE, Zamora D, Majchrzak-Hong S, Faurot KR, Broste SK, Frantz RP, Davis JM, Ringel A, Suchindran CM, Hibbeln JR. Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73). British Medical Journal. 2016: 353: i1246.
Ravnskov U, Diamond DM, Hama R, Hamazaki T, Hammarskjöld B, Hynes N, Kendrick M, Langsjoen PH, Malhotra A, Mascitelli L, S MK, Ogushi Y, Okuyama H, Rosch PJ, Schersten T, Sultan S, Sundberg R. Lack of an association or an inverse association between low-density lipoprotein cholesterol and mortality in the elderly: a systematic review. BMJ open. 2016: 6: e010401.
Reidlinger DP, Darzi J, Hall WL, Seed PT, Chowienczyk PJ, Sanders TA. How effective are current dietary guidelines for cardiovascular disease prevention in healthy middle-aged and older men and women? A randomized controlled trial. American Journal of Clinical Nutrition. 2015: 101: 922-930.
Rippe JM, Angelopoulos TJ. Sugars and health controversies: what does the science say? Advances in Nutrition. 2015: 6: 493S-503S.
Shadman Z, Khoshniat M, Poorsoltan N, Akhoundan M, Omidvar M, Larijani B, Hoseini S. Association of high carbohydrate versus high fat diet with glycated hemoglobin in high calorie consuming type 2 diabetics. Journal of Diabetes & Metabolic Disorders. 2013: 12: 27.
Siri-Tarino PW, Sun Q, Hu FB, Krauss RM. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. American Journal of Clinical Nutrition. 2010: 91: 535-546.
von Frankenberg AD, Marina A, Song X, Holly S. Callahan HS, Kratz M, Utzschneider KM. A high-fat, high-saturated fat diet decreases insulin sensitivity without changing intra-abdominal fat in weight-stable overweight and obese adults. European Journal of Nutrition. 2015.
Williams KJ, Wu X. Imbalan ced insulin action in chronic over nutrition: Clinical harm, molecular mechanisms, and a way forward. Atherosclerosis. 2016: 247: 225-282.
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2 comments


  1. David Nunan

    Hi,
    You write: “If you believe that the population is consuming an average of 383 calories below the recommended daily amount and less than the recommended 35% of calories from fat, then you have a lot more faith in the government statistics than I do.”

    You may want to read this. Not sure it’s the government stats that we need to worry about: https://slippdigby.wordpress.com/2016/06/15/fact-check-eat-fat-cut-the-carbs-and-avoid-snacking-to-reverse-obesity-and-type-2-diabetes-section-1-9/

    • Maloney Performance

      Thanks David. I retweeted Slipp’s piece a while back. One issue of many with the PHC ‘reports’.

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