Field Notes

Impact of Marketing Unhealthful Foods and Beverages on Kids

Research from McMaster University in Hamilton, Ontario, Canada, shows that advertisements for unhealthful foods and beverages high in sugar or salt have an immediate and significant impact on children and lead to harmful diets.

The study, published in the scientific journal Obesity Reviews, examined 29 trials assessing the effects of unhealthful food and beverage marketing and analyzing caloric intake and dietary preference among more than 6,000 children. Researchers found that the marketing increased dietary intake and influenced dietary preference in children during or shortly after exposure to advertisements.

Behnam Sadeghirad, PharmD, lead author of the study, says that these findings demonstrate the influence that these advertisements, a growing epidemic, have on children’s food choices.

“The rates of overweight and obesity among children are rising worldwide,” says Sadeghirad, a PhD student in clinical epidemiology and biostatistics at McMaster.

“This is the first systematic review evidence based on 29 randomized trials, and it shows that the extensive exposure kids have to marketing of unhealthy foods and beverages via product packaging (superheroes, logos), TV, and the internet increases their short-term caloric intake and preference for junk food,” he says.

For the study, Sadeghirad’s team looked at previous studies that examined advertising of unhealthful foods and beverages through television and movie commercials, video games, use of branded logos, packaging with licensed characters, and booklet/magazine ads.

When children were exposed to unhealthful advertisements, they consumed significantly more unhealthful than healthful calories, the study found. The findings also suggest that younger children (≤8 years of age) might be more susceptible to the impact of food and beverage marketing in terms of quantity and quality of calories consumed.

The researchers hypothesize that younger children might be more vulnerable to the influence of advertisements and associate the marketed products with positive features of commercials and subsequently try to imitate the behaviors they see.

The researchers say these findings are particularly important considering recent studies revealing that children are exposed to an average of five food ads per hour, with unhealthful foods accounting for greater than 80% of all televised food advertisements in Canada, the United States, and Germany.

“Overall, our analyses show the need for a review of public policy on child-targeted unhealthy food and beverage marketing,” adds Bradley Johnston, PhD, PDF, corresponding author of the study, an assistant professor in the department of clinical epidemiology and biostatistics at McMaster, and director of SORT (Systematic Overviews through advancing Research Technology) at The Hospital for Sick Children.

“The increasing prevalence of obesity seems to further coincide with marked increases in the food and beverage industry’s budget for marketing aimed at children and youth, with data showing that energy-dense, low-nutrient foods and beverages make up the majority of commercially marketed products,” Johnston says.

— Source: McMaster University


Moderate Exercise May Combat Prediabetes

Walking briskly on a regular basis may be more effective than vigorous jogging for improving glucose control in individuals with prediabetes, according to research from Duke Health.

The findings, published online in the journal Diabetologia, are the result of a randomized, six-month study of 150 participants, each of whom was designated as having prediabetes based on elevated fasting glucose levels.

Study participants were randomized into four groups. The first group followed an intervention modeled after the Diabetes Prevention Program (DPP), considered a gold standard that aims to achieve a 7% body weight reduction over six months. The program requires cutting calories, eating a low-fat diet, and exercising. Study participants in this group adopted the diet changes and performed moderate-intensity exercise equivalent to 7.5 miles of brisk walking in a week.

Other study participants were randomly assigned to receive exercise only using different amounts and intensities: low amount at moderate intensity (equivalent to walking briskly for 7.5 miles per week), high amount at moderate intensity (equivalent to walking briskly for 11.5 miles per week), and high amount at vigorous intensity (equivalent to jogging for 11.5 miles per week).

“We know the benefits of lifestyle changes from the DPP, but it’s difficult to get patients to do even one behavior, not to mention three,” says William Kraus, MD, the study’s lead author and a professor of medicine in the division of cardiology at Duke University School of Medicine.

“We wanted to know how much of the effect of the DPP could be accomplished with exercise alone,” Kraus says. “And which intensity of exercise is better for controlling metabolism in individuals at risk for diabetes.”

On average, participants in the DPP group had the greatest benefit, with a 9% improvement in oral glucose tolerance—a key measure of how readily the body processes sugar and an indicator used to predict progression to diabetes.

One of the exercise-only groups came in a close second. Participants in the moderate-intensity, 11.5-mile group saw a 7% improvement in glucose tolerance on average. The moderate-intensity, 7.5-mile group had a 5% improvement on average.

The lowest improvement was seen among those in the vigorous-intensity, 11.5-mile group, with only a 2% average improvement.

“Another way to say it is that a high amount of moderate-intensity exercise alone provided nearly the same benefit on glucose tolerance that we see in the gold standard of fat and calorie restriction along with exercise,” says Cris Slentz, PhD, a study coauthor and an assistant professor of medicine in the division of cardiology at Duke.

Kraus and Slentz say the study’s results could reflect the different ways in which high- and moderate-intensity exercise impact the body.

“High-intensity exercise tends to burn glucose more than fat, while moderate-intensity exercise tends to burn fat more than glucose,” Kraus says. “We believe that one benefit of moderate-intensity exercise is that it burns off fat in the muscles, which relieves the block of glucose uptake by the muscles. That’s important because muscle is the major place to store glucose after a meal,” Kraus says.

The authors note that only a diabetes outcome study could determine whether moderate-intensity exercise is actually superior to high-intensity exercise at preventing patients with prediabetes from progressing to diabetes. Still, Kraus said the study’s results could provide manageable alternatives for prediabetes patients.

“When faced with the decision of trying to do weight loss, diet, and exercise vs exercise alone, the study indicates you can achieve nearly 80% of the effect of doing all three with just a high amount of moderate-intensity exercise,” he says. “I was heartened by the fact that I found out that I can give patients one message and they can get nearly the same effect as when required to exercise, diet, and lose weight all at the same time.”

— Source: Duke Health