Tag Archive

To many, meta-analyses are seen as a research tool that is often regarded as the pinnacle of evidence in nutrition science. But is this accurate? What exactly makes a meta-analysis reliable or flawed? How can we distinguish between a well-conducted study and one that might mislead even the most well-intentioned reader?

In the realm of nutrition science and health, understanding the intricate relationship between various factors and health outcomes is crucial yet challenging. How do we determine whether a specific nutrient genuinely impacts our health, or if the observed effects are merely coincidental? This intriguing question brings us to the core concepts of correlation and causation. You’ve likely heard the adage “correlation is not causation,” but what does this truly mean in the context of scientific research and public health recommendations? Can a strong association between two variables ever imply a causal relationship, or is it always just a statistical coincidence?

Regression to the Mean (RTM) is a statistical phenomenon where extreme values on one measurement tend to move closer to the average on subsequent measurements due to natural variability. In this Premium-exclulsive episode, Danny gives an explanation of this concept with some examples in nutrition research.

Dr. Deirdre Tobias is a nutritional epidemiologist at the Brigham and Women’s Hospital and Harvard Medical School in Boston. She is an Assistant Professor in the Department of Nutrition at Harvard. In this episode we discuss the much-maligned food frequency questionnaire (FFQ) and it’s use in nutrition research.

There has been much debate about the role of nutritional reductionism in research. This approach generally aims to study diet’s effects by breaking down the intricate web of dietary factors into smaller, more manageable components. But critics have asked does this approach truly capture the full picture of nutrition’s influence on our well-being?

Effectively reading nutrition studies requires a nuanced understanding of statistical concepts and methodologies used in various studies. Developing this understanding can be challenging, especially for individuals without a background in statistics or research methodology.

Numerous nutrition studies present findings of “no effect,” but interpreting such results requires caution. A null finding, indicating an absence of impact from a nutrient or exposure, may not necessarily suggest a lack of effect overall. Instead, it could stem from issues related to the study’s design, the nature of the exposure, or participant characteristics.

Danny takes a look at some of the criticisms that gets levelled at nutrition epidemiology. Are they fair or misguided?

Food frequency questionnaires (FFQs) have been widely employed in nutrition research to assess dietary intake patterns among study participants. However, debates surrounding the reliability of FFQs have persisted both inside and outside the academic community.

The ‘exposure of interest’ refers to the variable or factor that is being studied to determine its relationship with a particular health outcome.
In this episode, Danny and Alan go through the most crucial aspects to understand about the exposure of interest in nutrition, hopefully leading to an enhanced understanding of interpreting nutrition research.

Introduction When thinking about the effect of eating or not eating a certain food or nutrient, we can’t consider this in isolation. Meaning, we need to evaluate the impact within the context of what such an inclusion/exclusion does to an individual’s overall diet pattern. Thinking about this concept, the phrase “compared to what?” has been colloquially used. And while this is an important idea, there has been some misapplication of this principle. In nutrition science, this is related to the concept of food or nutrient “substitution”. And this concept is crucial to understanding the issues that can arise in nutrition …

Never before has there been greater access to information about nutrition and health. But never before has there been such a low barrier to being seen as an “expert”. There are large numbers of people getting information from, and basing their health decisions on, people who don’t have direct expertise in the field in which they are talking about. Moreover, some promote the lack of domain expertise as a feature, not a bug. They claim that those that were conventionally seen as domain experts are either brainwashed, lazy in their thinking, or outright corrupt. And the solution is instead to look to those with a fresh perspective that can illuminate us on the “truth”. In this episode, Alan and Danny discuss this “death of domain expertise”, how it plays out online, and its ramifications for people’s ability to get good information.

Stable isotopes have been used as tracers in human nutritional studies for many years. But what are they? Why do we use ‘tracers’ in nutrition studies? And what are some practical examples?

In this episode, Dr. Alan Flanagan explains what stable isotope tracers are, how they are used to answer nutrition science questions, and some examples that you may come across.

In this ‘Ask Me Anything’ episode, Alan & Danny answer a range of listener questions. Topics include obesity rates, lowering blood pressure, cholesterol drugs, PCOS, and what issues they have changed their minds on.

While we’ve never known more about diet and health, there remain many unanswered questions in nutrition science. However, there is often disagreements on how best to answer these questions, particularly in relation to informing practical diet advise that meaningfully improves health.

Prof. Norman Temple is one academic who has written on a number of these issues. One issue he highlights is the large discrepency in the practical value we have attained from cohort studies and RCTs, relative to mechanistic research. Another is the limitations of RCTs for nutrition-specific research questions.

A recent study reported a higher risk of developing melanoma in people who ate a relatively high intake of fish. This study caused headlines and it was picked up by many outlets. In this episode, Alan and Danny dig into the nuances of this study to see if the headlines are justified.

In this episode Alan Flanagan discusses the concept of the GRADE system, and specifially how it applies to evaluating nutrition research and coming to conclusions for practice.

What is a biobank? How are biobanks used in nutrition science? Dr. Niamh Aspell explains all with examples of research using biobank data.

Dr. David Nunan, PhD is a Lecturer and Senior Research Fellow in the Centre for Evidence-Based Medicine at the University of Oxford. There, he is the Director of the Postgraduate Certificate in ‘Teaching Evidence-Based Health Care’ and the lead tutor for the internationally-renowned ‘Teaching Evidence-Based Medicine’ course.

He is a principal investigator with research interests in prevention and treatment of lifestyle-related conditions, improving the understanding and use of research evidence, and meta-epidemiology (research on research). David has experience in a breadth of methodologies including diagnostic studies, statistical analysis, qualitative research and clinical trials.

We discuss how machine learning could solve some current research limitations, as well as potential problems with its increased use.

Anthony Fardet, PhD is a nutrition science researcher in the Human Nutrition Unit at Université Clermont Auvergne, France.

His work has focused on a number of related areas; the consequences of the reductionist and holistic approaches applied to nutrition research, the relevance of a new classification of foods based on their degree of processing, and the role of the complex structure of the food in its health potential (“matrix effect”).

In this episode nutritionist Simon Hill discusses the barriers to eating a healthy diet, steps that can be taken to shift both individuals and the general population to a healthier dietary patten, and a number of other topics.

Dr. Mario Kratz is a clinical researcher in the areas of nutrition, obesity, and cardiometabolic disease, with more than 20 years of experience running clinical studies in a variety of populations. He is a former research associate professor at the University of Washington in the departments of Medicine and Epidemiology. And is also formerly an Associate Professor at the Fred Hutchinson Cancer Research Center in Washington state.

Prof. David Jacobs, PhD is Professor of Public Health, in the Division of Epidemiology and Community Health, at the University of Minnesota. He has published highly inflential work in nutritional epidemiology and health epidemiolgy for decades. A number of his papers have brought up crucially important ideas about how to do good nutrition science. Specifically, he has talked about think of whole diet or foods as the exposure of interest, rather than individual nutrients. Essentially warning against the pitfalls of applying a biomedical lens to nutrition research.

We take a look at three more “quacks” who spread misinformation; Dr. Michael Greger, Eric Berg, and Dr. Paul Saladino. We give reference to some specific examples.

To celebrate our 400th episode, we take a look at two “quacks” who spread misinformation; Dr. Aseem Malhotra and Dr. James DiNicolantonio. We give reference to some specific examples.

Dr. Leigh Frame, PhD is Director of Integrative Medicine at George Washington School of Medicine and Health Sciences in Washington DC. Dr. Frame received her PhD in Human Nutrition, as well as a Master of Health Science degree in Molecular Microbiology and Immunology, from the Johns Hopkins Bloomberg School of Public Health.

In this episode Danny and Alan talk with Dr. Deirdre Tobias about nutrition epidemiology, study design and diet collection methods.

Guest BioBrenda Davy, PhD, RDN Dr. Davy, is a Professor in the Department of Human Nutrition, Foods and Exercise at Virginia Tech. She conducts research investigating the role of diet and physical activity behaviors in the prevention and treatment of obesity and related comorbidities, beverage consumption and weight management, and dietary assessment methodologies. Dr. Davy received a BS in Nutrition in 1989 and an MS in Exercise Physiology in 1992 from Virginia Tech, and a PhD degree in Nutrition from Colorado State University in 2001. Dr. Davy is a Fellow of the American College of Sports Medicine and The Obesity Society, …