Junkfood Science: How about some science to go along with your cereal?

October 04, 2008

How about some science to go along with your cereal?

Are added sugars and foods low in fiber bad for kids and lead them to become fat?

Researchers with the Dortmund Nutritional Anthropometric Longitudinally Designed (DONALD) Study — the large German study that began recruiting waves of infants in 1985 and has recorded detailed information on the diets, growth and development, and metabolism of more than 1,200 children from infancy to adulthood — specifically examined the effect of carbohydrate quality and fiber intake on the development of body fat composition in early childhood.

Hundreds of media stories around the world have been reporting that breakfast cereals with milk and their cartoons characters loved by generations of kids are now villains for promoting “unhealthy” diets and contributing to an epidemic of obesity. But this study has received nary a blip in the news.

So, on behalf of children and worried parents, here’s the research media ignored.


This study* was led by Anette E Buyken, Ph.D., with the Research Institute of Child Nutrition, Rheinische Friedrich-Wilhelms-Universität Bonn in Dortmund, Germany and published in the American Journal of Clinical Nutrition. Each year, about 40-50 newborns are entered into the DONALD study and examined at 3-6 months of age and then, from the age of 2, every year they receive complete medical examinations, measurements, and 3-day dietary assessments where all the foods and drinks they consumed are weighed and recorded. For this analysis, the researchers used 380 infants born term who had reached the age of 7 and had complete information. As the authors noted, the BMIs of this cohort were representative of the German population of children.

Professor Buyken and colleagues examined each food the children ate looking for added sugars, as defined as: white sugar, brown sugar, raw sugar, corn syrup, corn-syrup solids, high-fructose corn syrup, malt syrup, maple syrup, pancake syrup, fructose sweetener, liquid fructose, honey, molasses, anhydrous dextrose, and crystal dextrose, as well as fruit syrups used as sweeteners in Germany. They also identified dietary fiber as defined by the Institutes of Medicine, to include the fiber from grains, breads, cereals, pasta, rice, baked goods, fruits and vegetables. Finally, they calculated the glycemic index and glycemic loads for the children’s diets which, the authors noted, some believe to be indicators of the quality of carbohydrates and high levels to contribute to the development of obesity. In other words, they wanted to see if refined sugars and refined grains were more fattening for developing bodies, than low-sugar and wholegrain, high-fiber foods, as popularly believed.

As the authors noted about this study design:

The present study has considerable strengths, including its prospective nature, repeated detailed measurement of both anthropometric and dietary data, and the ability to adjust for numerous major potential confounders. The repeated-measures regression analysis allowed us simultaneously to compare cross-sectional and longitudinal aspects of our prospective data and also to account for within-person correlations. In particular, the “change-on-change” analysis has been proposed to possess features of a quasi-experimental design, in which some participants are assigned to a change in dietary GI, GL, added sugar intake, or fiber intake, and other participants are not so assigned.


To summarize, the authors could find no relationship between the added sugars, dietary fiber, glycemic index or glycemic loads, the children consumed while toddlers at age two or throughout early childhood, and their percentage of body fat or BMIs at age seven. These null findings held regardless of how they analyzed the data (cross sectional, prospective, and changing each dietary variable). Even after adjusting for mother’s overweight, educational status, smoking, birthweight, weight gain from birth to age two, breastfeeding, age solid foods were introduced, and body fat at age two, they still could find no link between the added sugars or dietary fiber in the children’s diet and their BMIs or percentage of body fat. Without even a link, then scientists know that it's without merit to consider them as possible causes.

They said:

To our knowledge, the present study is the first to provide prospective evidence on the relevance of carbohydrate quality to the development of body composition in early childhood. In the present study, dietary GI, GL, added sugar intake, and fiber intake showed no overall association with the development of body composition in childhood, whether cross-sectionally at age 2 years, prospectively until age 7 years, or concurrently. In the present study, we did not observe any independent association of added sugar intake with the development of body composition… It is interesting that our analyses indicated potentially protective influences of added sugar intakes on BMI SDS before adjustment for dietary covariates.

Concerning fiber, they noted that it’s been suggested that insoluble dietary fiber may fill children up, reduce their appetites and could play a role in reducing weight gain. While they found that meal frequency was slightly reduced among the children consuming the highest fiber, it had such little measurable effect on their body fat or BMI it was not of clinical relevance. They also noted that “fiber intake was not related to weight change in the only prospective study in children and adolescents that is available to date.”

While some propose raising fiber intake in toddlers and children to reduce obesity or believing dietary fiber to be healthy, the authors noted that the benefits of fiber for children are unsupported in the medical literature, with scarce evidence to date. Such suggestions have been extrapolated from data on adults, they said. They also cautioned that “in early childhood, the optimal intake of dietary fiber is still subject to debate, because potentially adverse effects of a high dietary fiber intake on growth and mineral absorption have to be balanced with the presumed benefits.”

As they concluded:

On the whole, the present study does not support the common view that the quality of carbohydrate may be implicated in the current obesity epidemic in childhood. At least among healthy young children eating 6 times/day, carbohydrate quality does not appear to be relevant to their body-composition development between ages 2 and 7 years, whether cross-sectionally, prospectively, or concurrently.

Body of evidence

The results of this study were not unexpected. This study only adds to the body of the soundest evidence which, for some fifty years, has continued to demonstrate that sugars in any form do not lead to obesity or chronic diseases, such as diabetes and cancers. The scientific literature also shows that “healthy eating” for kids does not necessarily mean low-sugar or high-fiber.

Sugars do not make children ‘obese’, lead to chronic diseases of aging, cause hyperactivity, or do most of the other bad things popularly attributed to them. If anything, most studies show that children and adults with higher sugar consumptions have lower BMIs and better nutritional status.

Nor are sugars as enjoyed by generations of children around the world 'empty calories' or been shown to adversely affect nutritional status. In fact, the Food and Nutrition Board of the Institute of Medicine, upon reviewing the scientific literature while drawing up the Dietary Reference Intakes, had concluded there was insufficient evidence to support even setting limits for sugar intake. Not only have most parents and kids been eating sugars at reasonable levels without evidence of nutritional or health concerns, the amount of carbs in our diets haven't appreciably changed in a century.

The evidence on sweeteners has been covered at length, for example: Science of sweets (high fructose corn syrup, brain food, role in chronic diseases, 50 years of evidence), More bad carb myths, Traffic tickets for sugar (latest evidence examining if sugar is linked to higher body weights), Do you fear sugar might cause cancer?, Sweet kids and hyperactivity (including the empty calorie myth), and It will rot your teeth out. Sadly, many continue to incorrectly fear that sugars lead to obesity and chronic diseases; and little kids, who have sweeter tastes than grown-ups, are being taught to fear that sugar is bad for them and are being put on low-sugar diets.

Decades of research on the development of childhood obesity has been slow to reach mainstream media or even many healthcare professionals. The truth of the matter is that regardless of their diets or physical activity, children naturally grow up to be a wide range of heights and body weights. Regardless of how intuitively incorrect it might seem, the strongest body of both clinical and epidemiological research has continued to show that fat children as a group normally eat no differently than their thinner counterparts.

An earlier DONALD study had clinically followed children, weighing them and recording their diets at least ten times a year and followed them thusly for 17 years. It found that no matter what the children ate during childhood or adolescence, they naturally grew up to be a wide range of weights. While there were great differences in the children’s diets, these differences weren’t at all related to their weights.

Multiple researchers, using a variety of methodologies, have failed to find any meaningful or replicable differences in the caloric intake or eating patterns of the obese compared to the non-obese to explain obesity, concluded David Garner, Ph.D. and Susan Wooley, Ph.D., in their classic 1991 review of 500 studies on weight.

As a 1996 AHA Scientific Statement for healthcare professionals concluded, after reviewing all of the evidence: “Studies of diet composition in children do not identify the cause of obesity in youth.” So, it’s little wonder that even the most intensive and comprehensive efforts to address obesity by dietary interventions have continued to fail to have an effect on childhood obesity.

Despite the science, beliefs are being popularized that healthy eating for young children means low-sugar, low-salt, low-fat, low-calorie and high fiber, and that the diets of today’s children are dreadful and that interventions are imperative because eating habits set in childhood are for life. [Click on links to the research on each issue.] Rarely mentioned are that the resulting interventions are far from harmless, nutritionally and in heightening food fears and lifetimes of disordered eating, or that there is no evidence that such interventions are effective.

Favorite kid cereals

Tony the Tiger to Captain Crunch, which generations of kids have grown up with, have been targeted this week as villains for making kids fat and promoting unhealthy foods. Cereals said to have too much sugar (12-15 grams, only 2 to 3 teaspoons per cereal bowl) were rated as “the worst” by Consumer Reports. This consumer magazine also judged the healthfulness of cereals based on their sodium, fiber and calories. Lucky Charms, for instance, rated far above Fruit Loops.

Consumer Reports also said that adults eat more than half of children’s cereals and they should be concerned, too. Kellogg’s Organic Raisin Bran and Mueslix have 16 grams and 17 grams sugar, respectively, but these cereals didn’t make the bad list. They’re not as much fun, perhaps?

Dr. Orly Avitzur, M.D., at the Dept. of Neurology of Yale University School of Medicine, and medical advisor for Consumer Reports and Medscape/WebMD was quoted in WebMD saying that cereals higher in fiber and “not full of sugar, which is just empty calories,” are better.

Marlene Schwartz, Ph.D., Deputy Director of the Rudd Center for Food Policy and Obesity, was quoted in ABC News as saying: “We found that kids' cereals were worse on every count.” They’re higher in calories and sugars and lower in “things you would want like fiber,” she said.

Identical stories blaming long-time children’s cereals for contributing to childhood obesity were also reported in the UK this week, with the group “Which?” calling for bans on cartoon characters marketing cereals to children. Despite such claims of cereals as fattening and unhealthy, fortified cereal with milk and juice have begun busy days for countless kids, since long before the "childhood obesity epidemic." Kids who eat breakfast have better overall nutritional status and there's no evidence that cereals are unhealthy or dangerous.

Anytime we see such orchestrated marketing, especially when it’s weak on science, there’s usually more to the story. What was not disclosed by the media, is that Consumers International, which publishes Consumer Reports, has a global lobbying campaign to get the World Health Organization to ban the marketing of all unhealthy food and develop an international code restricting all advertising and marketing of foods high in sugar, fat or sodium to children, accusing these foods of making the world’s children fat. CI is using the “obesity pandemic,” and this initiative was actually authored by the International Obesity Task Force of the International Association for the Study of Obesity.

Scary stories about the dangers of certain ingredients or foods that kids and families have enjoyed for generations are not really about sound science, obesity or health. Sadly, worried young people and parents may not realize that. The best protection for consumers isn’t found in a magazine or media story, but in the science.

© 2008 Sandy Szwarc

* Study disclosures: “The Ministry of Science and Research of North Rhine Westphalia, Germany, supported this study. None of the authors had a personal or financial conflict of interest.”

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