I’ve thought about writing this post for a while. I think about it (while gnashing my teeth) every time I see one nutrition-related scientific study or another badly misrepresented in the media. So now I’m writing it, and the catalyst is the recent brouhaha about the latest low-carb vs. low-fat diet study (aka, beating a dead horse).
You cannot get a good answer to a lousy question.
The larger body of scientific research has already demonstrated that diets don’t work for long-term weight loss, that any food plan that results in a reduction in calories is likely to result in short-term weight loss, and that not all people respond equally to the same macronutrient (carbohydrate, protein, fat) manipulations. Further, the continued reductionist view that all carbs are the same and all fats are the same is problematic. As Katz points out, “everything from lentils to lollipops is a carbohydrate.”
In this study, the low-carb group reduced their carb intake much more than the low-fat group reduced their fat intake. The low-carb group also reduced their overall calories more than did the low-fat group. According to this Reuters article, diet quality appeared to improve among participants in both groups.
Unfortunately, many of the media reports about this study were far less nuanced, and while the study du jour may change, this is a pattern that is unlikely to change. I see several factors contributing to this poor state of nutrition reporting:
- Print journalism is suffering (i.e., bleeding money) and staff sizes are shrinking. Few newspapers have qualified, experienced, dedicated science reporters on staff anymore.
- The immediacy of the news cycle has changed in our internet and social media age. New stories have to be published now, now, now! No time for critical thinking!
- We have more and more voices competing for our attention (also thanks to the internet and social media). Often, the loudest (read: most sensational) voice wins, at least for the moment.
In some cases, the main limitation is that further research is needed to clarify/confirm the findings of the study in question. That’s how science works…if your findings can’t be replicated, then your findings are not valid.
Additionally, when it comes to nutrition, what applies to one demographic may not apply to all. A study using only male subjects may not apply to women; a study using only young healthy subjects may not apply to people who are older or who have chronic diseases. This qualifies as a limitation.
In a nutshell, very few research studies are as groundbreaking as they are portrayed to be in the media, and talk of “paradigm shifts” in nutrition is little more than hot air. Good science just doesn’t move that fast.