NEWSBREAKS INCLUDE:

* Processed/Ultraprocessed foods and health.

* Ultraprocessed food policies

* Nutrition interventions

* Global look at dietary quality

PROCESSED FOODS AND HEALTH

The media and journals are filled with articles about the implications of processed and ultraprocessed foods on health. The definition of the term varies from a focus primarily on processing to one involving the ingredients that are used to make the food and whether industry makes them. Those who discuss them usually include packaged foods that have been made by food companies using many manufactured ingredients. Some examples would therefore include hot or cold packaged snacks, pre-packaged meals, sweets and sodas, to name a few. The reason for all the interest is that some studies have found associations between ultraprocessed foods and health, including obesity, and some chronic diseases. If the cause of the trouble isn't just that people are eating more food and thus more calories, but instead it is something in these foods that throws off appetite and satiety mechanism, this would have many public health implications. Several very good papers have been published in the past few months that examine these issues in greater depth.

First up is a document produced by the Scientific Advisory Committee on Nutrition(SACN) a government body in the United Kingdom that focuses on the associations between processed foods and health. It is a long and carefully researched document that exhaustively reviewed the evidence available about these connections. It concluded that it was uncertain that consumption of processed (or ultraprocesse) foods were associated with increased risks of poor health outcomes because the quality of the evidence of causations was poor, since the studies claiming such effects were almost all observational in nature. This type of study makes it difficult to account for factors such as energy intake, body mass index, smoking, and socioeconomic status. A second problem they found was that consumption of the processed foods often seemed to be an indicator of other unhealthy dietary patterns or lifestyle behaviors. That is, diets high in them are often energy dense, high in saturated fat, salt, or added (free) sugars, processed meat and and low in fruits, vegetables, and fiber, all factors that themselves may be associated with poor health outcomes. SACN has evaluated the evidence in other publications on those other nutritional factors and found that may were related to health. Because of these uncertainties, the report concluded that a classification system to better document and monitor the consumption of these foods in diets was needed. More high quality randomized clinical trials and better prospective cohort studies were needed. Studies of the benefits of consuming dietary intakes with a pattern of minimal processing compared to dietary patterns following existing government recommendations would be useful. Finally, SACN recommended examination of processing methods and/or food additives that might be linked to health.

Source: SACN Statement on Processed Foods and Health: Summary Report Office for Health improvement and Disparities. London July 2023 available at:

https://www.gov.uk/government/publications/sacn-statement-on-processed-foods-and

ULTRAPROCESSED FOODS AND OBESITY RISK

Second and another deep dive is an excellent review by a team at Purdue University. These scientists looked at all of the reported mechanisms for why ultraprocessed foods might be linked to obesity, along with a critical look at how strong the evidence was for each. They found for some of the theories that placed the blame on the UPF's fiber content, texture, gastric emptying or gastric transit time, the effects of UPF versus non UPF diets on appetite, food intake or body fatness levels didn't seem to show effects that made sense from the data. For other theories, such as changes in the microbiome or the presence of food additives, there simply wasn't any data available to implicate UPF, while for others like packaging, food cost, shelf life of the food, macronutrient intakes and appetite stimulation, data were scanty. Finally, there were a few examples of UPF with healthful uses, such as artificial sweeteners instead of sugar, or certain additives that decreased likelihood of food borne illness. The bottom line at least for now is that it is too early to make recommendations based on classifications based on processing.

Source Valicente VM, Peng CH, Pacheco KN et al Ultraprocessed foods and obesity risk: a critical review of reported mechanisms Advances in Nutrition https://doi.org/10.1016/j.advvnut.2023.04.006

US POLICIES ON ULTRAPROCESSED FOODS

The last in the trio of articles on UPF is a useful compendium of policies and guidance from various sources in the USA on consumption of processed and UPF. In the USA, there has been little direct policy targeting UPFs, although some documents suggest that they may be contrary to achieving healthy diets. In contrast, in some other countries school food programs and dietary guidelines are more specific. But before making policy about UPF, some of the questions raised about the quality of the evidence available about them and their causative role will need to be answered.

Source: Pomeranz JL Mande JR, Mozaffarian D US policies addressing ultraprocessed foods 1980-2022 American J Prev Medicine doi: https://doi.org/10.1016/amepre.2023.07.006

CREDIBILITY OF NUTRITION INTERVENTION STUDIES

Those of us who spend our time trying to help people change their food habits are always looking for programs that work. But they are sometimes hard to find. What could help a lot is to know, particularly in studies that involve randomized controlled trials of nutrition interventions, what the prespecified outcomes and intended effects of treatment were supposed to be. A group of investigators at the Federal University of Santa Catarina in Brazil took a random sample of trials published in 2019 and 2020 to see if studies were registered in advance and if enough information was provided so that outcomes and intended treatment effects were clearly stated. The good news was that over two thirds of the trials were registered and that they provided additional details. This is a big improvement from years ago, when registers didn't exist at all or were rarely used. However, performance was not so good when it came to the research study authors specifying in advance exactly what they were studying, what the protocol was, and how they expected to analyze results statistically. The bad news was that information on protocols (14%) and statistical analysis plans (3%) were often not available, and almost all of the studies gave only limited information of the type needed to assess risks of bias stemming from the selection of the reported result. The group concluded that the information provided failed to fully specify outcomes and what the intended treatment effects were, making it difficult to get an idea of exactly how credible the results were. The results suggest that those of us who do intervention studies still have a way to go in improving our reporting.

Source: Mello AT, Kammer PV, Nascimento GM et al Credibility at stake Journal of Clinical Epidemiology 2023 doi:https://doi.org/10.1016/j.jclinepi.2023.06.021)

BMI AND BEYOND

What are the pros and cons of using the body mass index (BMI) to measure fatness and of using it as a measure of fatness and health? And are there social as well as clinical implications that arise from its use? The National Academies examined these questions in depth during two workshops earlier this year, and the documents are well worth a read. It is sometimes forgotten that it has only been in the past 30 or so years that BMI cutoffs have been widely adopted as measures of overweight and obesity, and for only about half of that time has intensive behavioral therapy for a BMI of 30 or over been reimbursed by the Centers for Medicare and Medicaid Services in the USA. BMI is increasingly recognized as an imperfect but useful measure of fatness. However, it is only a screening measure and needs to be followed up with further clinical assessment. Also, when BMI changes with treatment, it only imperfectly measures how much of the weight loss is fat and how much lean. Increasingly it has become clear that BMI is an imperfect predictor by itself of future disease or mortality. The workshops discuss a path forward that involves using BMI for screening and evaluating risk factors for various conditions and diseases, going beyond it to other measures that compensate for its limitations.

Source: National Academies of Sciences, Engineering and Medicine BMI and Beyond: Considering A context in Measuring Obesity and its Applications: Proceedings of a Workshop in Brief. Washington DC 2023 The National Academies Press (access at https://doi.org/10.17226/27185

DIETARY QUALITY MEASURES GLOBALLY

Recently a group of researchers at Tufts University examined data from different countries against healthy dietary patterns such as the Alternative Healthy Eating Index (with a range from 0, the least healthy, to 100 the healthiest). They also evaluated them against the Dietary approaches to Stop Hypertension and the Mediterranean Diet Score. Generally, dietary quality was modest worldwide. For example, in 2018, the mean global AHEI was about 40, ranging from 30 in Latin America to 46 in the Caribbean and South Asia. Scores were generally higher among women than men, and higher in more compared to less educated individuals. Although in most regions the scores of children's' diets were similar to those in adults, but in Central /Eastern Europe, central Asia, high income countries, the Middle East and Northern Africa, children had lower diet quality than their elders.

Source: Miller V, Webb P, Cudhea F et al Global dietary quality in 185 countries from 1990 to 2018 show wide differences by nation, age, education and urbanicity Nature Food 3: 694-702 2022