Why diet studies are so often inconsistent ?

Whether it’s eggs, milk, fish or meat, scientific studies often contradict each other on the advice to follow to be healthy. But why ? English researchers have looked into this question, their results have just been published in the journal American Journal of Clinical Nutrition. They believe that it could come from statistics and methodology.

Methodological differences between studies cause misleading results

“It is well known that different nutritional studies tend to yield different results, believes Georgia Tomova, one of the authors, in a communicated. One week a food is apparently harmful and the next week it is apparently good for you.”.

In fact, scientists from the university of leeds and of the Alan Turing Institutethe National Institute for Data Science and Artificial Intelligence, found that the methodology commonly used to study the health benefits of foods often yields misleading results.

The authors believe that, from a methodological point of view, several things can skew the results or make them very different from one study to another. The first point is that the total energy consumption of the participants via food, and therefore calories, is not always controlled.

Improve the methodology of future studies

Second, researchers don’t always check for volunteers’ consumption of other foods when conducting a study. “Unfortunately, since most studies have different approaches to controlling the rest of the diet, it’s likely that each study estimates a very different amount, making the average rather meaningless.”, says Georgia Tomova.

“Different studies may provide different estimates for various reasons, but we believe that this statistical issue alone may explain much of the inconsistency, points out Dr Peter Tennant, Associate Professor of Health Data Science at the University of Leeds Medical School. Fortunately, this can be easily avoided in the future”.

The authors of the study hope that their work will help future researchers to better refine their methodological criteria and thus conduct more reliable food studies.

There is one thing that is certain: per day, the amount of calories an adult needs on average is between 2,400 and 2,600 calories for a man and 1,800 to 2,200 calories for a woman.