With so many news options available to listeners, tweeters, readers and viewers, news reporters compete aggressively to draw in their audience. Whether in the form of a headline, a tweet or a 'Tonight’s Top Stories!' blurb, the press entices you to tune in to their page, hashtag or channel.
News editors and bloggers have many tricks to grab your attention with a headline and lead you to a desired conclusion even before you read, listen or explore further. One of the cleverest is creating a controversy by making a statement that contradicts what you’d expect – after all, why would you want to check out something you already know? Headlines or titles like Fat makes you Thin or How to Embezzle Legally, are much more intriguing than the 'duh factor' behind Fat makes you Fat or Embezzling will get you Arrested.
Headlines serve another purpose in our modern world of information overload. According to David Ogilvy, a legend in the advertising world, "five times as many people read the headline as read the body copy.” Thus, some bloggers or tweeters are happy for the public to absorb the main message from their title, knowing that it’s unlikely they’ll have time to delve into the information behind their catch phrase.
A prime example of this in the field of nutrition is the reporting surrounding the research on low-calorie sweeteners (LCS). A variety of LCS have been around for years and evaluated extensively for safety. While it’s logical to assume that replacing sugar, or other caloric sweeteners, in your diet with LCS would result in a lower caloric intake and weight loss (and many studies have shown that to be the case), some epidemiological and a few basic science studies have suggested the opposite - that LCS may trick our brains or metabolism into overeating and gaining weight.
To draw in their audiences, bloggers, news editors and tweeters have focused more on this limited, but more controversial research, by selectively featuring research that concludes “Low-calorie Sweeteners make you Fat” rather than on research supporting the less intriguing research that “Low-calorie Sweeteners help with Weight Loss.”
In contrast to the news media’s penchant for reporting the more controversial research, the scientific community has continued examining all aspects of LCS. In a study published in the September 2014 issue of the American Journal of Clinical Nutrition (ACJN)1, Drs. Paige Miller and Valerie Perez conducted an extensive meta-analysis of independent research examining the relationship between LCS and weight control in generally healthy human subjects.
A meta-analyses is a formal quantitative approach for grouping scientific data reported from many independent studies, thus allowing the aggregated data to achieve a higher statistical power for the treatments being measured than is possible in the single studies.
In one of the most comprehensive scientific evaluations to date of LCS, weight and body composition, Perez and Miller specified a rigorous set of eligibility criteria for a study to be included in their meta-analysis. The first element in their criteria was that the study design had to be either one of two types: 1) a randomized controlled trial (RCT) - the recognized gold standard in evidence-based research; or, 2) a prospective cohort observational study.
An extensive PubMed search, covering almost four decades (1976-2013) of research, produced over 500 studies. Among these, 15 RCTs and 9 prospective cohorts met the eligibility criteria for inclusion in the meta-analysis, pooling data for nearly 2,000 subjects in the RCTs and more than 100,000 participants in the cohorts.
The analysis of the observational data showed a slight positive association between LCS and BMI, but no relationship with body weight or fat mass. The authors concluded that interpreting the results from the cohort studies was limited by the lack of control of important confounding variables such as energy intakes, and baseline weight and body composition differences between users and non-users of LCS.
In contrast, the RCTs, which provide the highest quality data for examining the possible causal relationships between LCS consumption and weight parameters, showed that the use of LCS resulted in a modest but significant reduction in body weight, fat mass, BMI and waist circumference.
In an editorial, published in the same AJCN issue as the Miller and Perez study, James O. Hill, a recognized expert in the study of obesity and weight management, said the conclusions of the meta-analysis were "clear and powerful". So what does this mean for the consumer, he asked and then answered: It means that LCSs seem to be doing exactly what they were designed to do: helping reduce total energy intake while providing the sweet taste we value. This is good news for people trying to lose or not to gain weight.
Unfortunately, the good news this study reports is often underreported in the popular mass media, leaving consumers uninformed about the solid science that might make a positive difference in their weight management efforts. For now, the burden is on the consumer to read beyond the headlines and explore the science behind them. And, perhaps, more critically, the burden also rests with scientists who must find their own way to intrigue consumers away from the imbalance of the hot headlines, and show them how well-founded science can make a real difference in their lives.
1. Low calorie sweeteners and body weight and composition: a meta-analysis of randomized controlled trials and prospective cohort studies.
Miller and Perez Am J Clin Nutr September 2014 100: 3 765-777
Susan Adams MS RD is a Seattle-based dietitian serving the food, nutrition and related medical needs of the elderly. She is a former national media spokesperson for the Academy of Nutrition and Dietetics and regularly provides expert counsel to the Aspartame Resource Center.