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.
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.
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).
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
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%).
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
The 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
As 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).
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.