Conflicts of interest part 1
Are conflicted nutrition professionals the reason we have pretty crap diets?
An article last year in the Washington Post described how the food industry pays dietitians to promote their products.
Alongside this, high profile books about nutrition science and food industry consistently highlight the financial relationships between nutrition professionals and food industry as a/the reason behind our weak dietary guidelines. Both because “industry-conflicted” dietitians and nutrition scientists sit on guideline committees and because industry-funded research creates biased outcomes in favour of industrial food products.
As always I think there is a lot of nuance to whether and how nutrition professionals can/should work with/for industry, and thought I would express my views. Ultimately I think this is a complex issue and I have close colleagues I respect who think my views are too strict; and others who think we should be more strict about this.
I think this is an important area that (rightly) attracts a lot of interest and I thought I would offer my views.
I’ll cover this one in three parts.
Part 1: Are conflicted nutrition professionals the reason we eat pretty crap diets?
Part 2: Is a need for attention an ENORMOUS conflict of interest? (Yes).
Part 3: Should nutrition professionals interact with industry? And how?
Let’s break this first part down into guidelines, the research base, why people eat what they eat; and finally where the real issue lies - POLICY.
Do I think conflicts of interest on the part of nutrition professionals have influenced dietary guidelines?
No, not really. At least I don’t think it does. IMO our guidelines aren’t as forthright as they could be but if conflicted nutritional scientists are playing a role, it is minuscule compared to the following factors:
Nutritional research is really hard to do. We largely rely on observational studies and long-term free-living trials where we don’t really know what people are doing. There is so much noise and confounding in these studies, we really can’t get much precision out of them. Plus, there’s probably a lot of wiggle room for “unhealthy” foods within a healthy diet. Therefore, guidelines tend to be a bit wishy-washy.
Guidelines aren’t only based on what the evidence says!
For example, in the US, the committee of nutritional experts (Dietary Guidelines Advisory Committee (DGAC)) writes the report of recommendations based on an assessment of the evidence which then gets sent to the U.S. Department of Health and Human Services and the Department of Agriculture where it can be modified and is then published. This conflict between what nutrition scientists recommend and what gets published following review by departments subject to substantial lobbying has been criticised in the past, including by nutritional scientists themselves.
In the UK, a modelling process adjusts the recommended food group sizes after taking the current intakes of the most commonly consumed foods in the UK to make the fewest possible changes needed to achieve the proposed recommendations.
Let me give you a practical example of how challenging writing guidelines is:
I think the dietary guidelines for people with type 2 diabetes should specify that a high-protein, low-carbohydrate diet can lower glucose without weight loss because independent research groups have shown really big reductions in glucose with this diet in very short-term (5 to 10 week long) very well controlled trials. Although these studies are short in duration, an advantage of this is that they can control for confounding factors much more.
But…. ultimately what causes early mortality of people with type 2 diabetes is heart attacks and strokes; and the longer-term evidence is a bit grey and some of it points towards (it’s much weaker evidence) a high-protein, low-carbohydrate diet being associated with higher mortality.
So as a dietary guidelines committee what do you do? Recommend a diet that lowers glucose in the short-term but might worsen other elements of cardiometabolic health? Or make a non-committal (but balanced) statement that “from this [mixed] evidence there is no reason to recommend any specific ideal proportion of macronutrients”. Honestly, this isn’t objectively wrong, is it? Personally, I might have stuck my neck out and highlighted why different types of evidence are stronger than others, and would have added some nuance by recommending a “plant-rich” high-protein, reduced-carb diet to help lower blood pressure, lower LDL-cholesterol to take into account overall cardiometabolic health. But you can see from this example that even as an advocate of one type of dietary approach, I can see it’s never a slam dunk with the limitations of nutritional evidence we have to draw on.
And as much as people point to the example of how the sugar industry’s funding of scientists and other bodies has meant guidelines left sugar alone as a nutrient of concern, I don’t really think it has. The sugar sweetened beverage industry has certainly worked ruthlessly to influence academics, and to promote studies showing their products in a more favourable light in the general press and amongst the public (which likely swayed how people voted on whether a soda tax should be implemented). But since the first American dietary guidelines were issued in 1977, they have recommended reducing added sugar intake to fewer than 10% of overall calories, a recommendation which has been further reduced and strengthened over time. (And largely I think this has followed what controlled trials have shown). Now should dietary guidelines recommend no sugar at all on the basis it has no positive nutritional value? Maybe* but this wouldn’t be reflecting the empirical evidence which shows at low intakes it has no detrimental impact on anything meaningful we can measure.
Note - guidelines are not the same as policy which I’ll cover in the last section, and which has undoubtedly been influenced by lobbying.
Do I think industry-funded research has weakened the evidence base we can draw on to make conclusions about the relationship between food, nutrients and health?
Even if industry connections on the part of nutritional professionals have not altered the quality of dietary guidelines, it’s definitely possible that industry-funded scientists and research means that we have a biased evidence base to draw on in the first place.
It’s true that industry funded studies are more likely to find a beneficial outcome from whatever product or food is being tested - whether almonds, sugar, artificial sweeteners or dairy products. Personally, I’m doubtful that a Hass avocado-funded study which shows that avocados improve the lipid profile; or a Dairy Council funded study showing yoghurt doesn’t worsen insulin sensitivity are meaningfully altering how we understand the impact of diet on health. And many are too poor quality to be included in dietary guidelines anyway. I do acknowledge that maybe the cumulative effect of this research is an overall more “positive” evidence base and this biases guideline committees views towards individual foods and food products? But my sense is that overall, the “conflicted” research achieves equipoise: BigNut, BigFruit, BigMeat, BigDairy and BigWheat all basically cancel each other out, haha.
Furthermore, the really impactful (or controversial) research questions have been the ones to attract funding from governmental agencies - eg dietary patterns on health; sugar intake and obesity/cardiometabolic health; the energy density of the diet and weight gain; and low-carbohydrate diets on weight loss (in fact I think this question has been beaten to death despite very few data indicating they do anything metabolically special).
The one area that I do think is interesting is whether the nutrition science world has been too slow to study the impact of processing on food intake and weight gain/cardiometabolic health. And whether industry-funding has played a role in this? Personally, I think that it has been a blind spot, but since the issue of degree of processing began being discussed in the scientific literature around 2010 research has exploded in this area.
In summary, we may have an evidence base which has been shaped by industry funding to a certain extent, but I am skeptical as to how much this has had a meaningful impact on the quality or accuracy of the guidelines.
Do I think conflicts of interest on the part of nutrition professionals are the reason people have very unhealthy diets generally?
No. I know I am an industry-conflicted nutritional professional but hear me out:
The first point is that guidelines have minimal impact on dietary behaviours in the vast majority of people. (They do influence what foods an institution might present to people though, especially in schools). But purchasing and intake is primarily driven by price, taste and convenience. “Information” or “knowledge” actually has a tiny role in dietary intake.
For example I do laugh when I hear people say “we need to put ultraprocessed warning labels on foods so people know they’re unhealthy”. Every week millions of people enter McDonalds which sells salads and apple slices and every week 99% of these people choose fries, coke and a McFlurry.
The Food Standards Agency in the UK reviewed the impact of food labelling purchasing behaviour and concluded “where nutritional labelling systems alone have been used to shift behaviour, studies consistently show that this method alone has no reliable effects”.
What about those social media videos of dietitians promoting sugary foods** like chocolate, ice cream and lollipops (I kid you not), having been paid by industry? To be clear, I wholeheartedly condemn this - there are very few black and white areas in nutrition but sugary snacks have to be one of them. They have no nutritional benefit; people have far too much; and promoting them is just morally wrong in my opinion. Honestly I view this type of thing as credential-pulling… But (and maybe I am naive) I can’t fathom that your average member of the public watches one of these (honestly kind of cringe?) videos and says “oh gee, I thought doughnuts were bad for me but now I’ve changed my mind….?”. You might be thinking well why would BigSugar pay for these ads if they’re not effective? Perhaps they’ve got billions and chucking a couple of thousand at some dietitians is worth a shot? (HONESTLY CYBER-PUNCH ME IN THE COMMENTS IF YOU DISAGREE).
Likewise I disagree with there being any financial relationship between professional nutrition organisations and food industry. Mostly because it is really tiresome going to nutrition conferences and seeing cocacola or danone sponsoring it, or having to sit through some industry-sponsored symposium on a new high-protein yoghurt. From experience (I am UK and US registered), it is worse in the US, and I actually left the Academy of Nutrition and Dietetics because of all the industry sponsorship. So it’s not that I agree with this type of stuff or that I think it has zero impact (see below in policy), it’s just that I don’t think its remotely impactful compared to other issues.
Ultimately, the biggest reason our diets are pretty unhealthy is because there is palatable, well-marketed, delicious convenient unhealthy food constantly available pretty everywhere; and humans cannot resist it. In particular, this affects the poorest in our society, who also have the highest risk of obesity and ill health.
And even if you’re lucky enough to live in a nice area and have a comfortable life, if you consider what you’re exposed to as your navigate your days, what’s the default option for food? It’s basically the rubbish food isn’t it?
And this comes down to policy.
Food and public health policy could really improve what we eat but this is incredibly hard to do - because there is lots of complexity around larger issues like trade, employment and tax income, but also because there is a ton of lobbying aiming to prevent any meaningful policy changes.
I note some of the points about how hard it is to get food policy right in my post on ultraprocessed foods because there are some grey areas.
However, there is no doubt that lobbying by the food industry has stymied even the most lukewarm efforts to improve the nation’s/world’s diets. Restricting advertising of sweet stuff to kids, taxing sugary drinks? You name it, food industry has lobbied against it.
And here there is evidence that food industry has paid professional societies, which - in some shocking cases - have watered down their positions against, for example, sugar and dental health or even the soda tax. I also think that nutritional, medical and health organisations need to speak with one voice on these issues where we are very clear about the evidence because food industry will exploit any “well actually hydration is important and coke provides fluids, so they’re not completely bad” greyness.
But ultimately the views of nutritionists (literally noone cares what we think haha) and medical societies pale in comparison to the fiscal drivers of any policy. Like I stated above, nutrition experts write what they believe should be the US dietary guidelines and then they get turned into the actual guidelines and then policies by everyone else.
Here is a brilliant review summarising the systemic challenges in changing food policy which encompass globalisation, farming policy and production practices, national and international trade agreements, and ecosystem influences.
I am pretty sure I remember Chris Van Tulleken recounting that Matt Hancock (or whoever the health minister was at the time) had said to him “oh yeah Chris, we absolutely know we know the food industry is a major driver of the nations’ poor health but they employ millions of people and pay millions into the treasury and we can’t risk the impact on the economy”. I’m paraphrasing because I can’t find that clip now, but this is what it ultimately comes down to. Nutrition professionals are a tiny (negligible?) driver of food and public health policy compared to larger fiscal and political interests***.
Next post:
The reason I am writing all this is because if we want effective food and public health policy, we have to accurately understand the key drivers of those policies.
And I hope I have laid out why “conflicted” nutritional professionals plays a minuscule role. The reality is a lot more complicated; and we need the public to understand how and why we need to change our approach, as ultimately politicians are mostly going to be influenced what people vote for at the ballot box.
In other words, we could have a big campaign to cease all financial relationships between nutrition organisations and food industry (I am for this); and prohibit industry from working with or funding nutritional professionals (I disagree and will cover this in post 3); and it would change diddly squat.
So my next post is going to focus on the dangers of over-simplifying the narrative in order to sell a book. HAHAHAHAHA.
* In general I think firm clear guidelines are better than waffle; but guidelines (information) actually do precious little to change behaviours anyway.
** I’ll come to the rest of the products promoted in that Washington Post article in part 3.
*** In part 4, I am going to get to what I would do to change food intake (if I were powerful), and libertarians are going to hate it.
Nutritionists do have an impact -- they are frequently guests or quoted in media spots that normies listen to and watch on the regular. Sadly, too often, the nutritionists I've seen do media spots don't inspire much confidence in the profession.
Some really useful perspectives, I hadn't previously considered. Looking forward to the next parts.
One thing to consider is what's meant by 'nutrition organisations': there are a number of independent organisations who provide credible, evidence-based advice yet have affiliations to food companies. Like you say, the topic is immensely complex.