Junkfood Science: Feeding our children well

December 11, 2006

Feeding our children well

A recent post mentioned the growing body of research showing obesity fears and “healthy eating” messages have taught children that low-calorie and fat-free foods ARE good nutrition. Even adults, especially women, have come to believe low-fat, low-calorie (and low everything) means healthy eating. But a story in the news today demonstrates how extreme the fears of fat have become, not only among parents, but even degreed professionals caught up in the anti-obesity frenzy. It points to very real dangers possible for their children and others following their example.

The Rudd Center for Food Policy and Obesity at Yale awarded a mother from South Jordan, Utah, $1000 for coming up with “A+Lunches” — ideas for parents to give their preschool and school children to “battle the ‘global obesity epidemic.’”

It is typical of the menus increasingly being recommended by anti-“childhood obesity” activists. The lunch includes no sweets, no meat and no “fattening” foods, only foods believed to be “healthy”: carrot and celery sticks, a few apple wedges and berries, a small dollop of peanut butter between flower-shaped pieces of bread, and skim milk. The mother tested it on her four-year old.

A brief nutritional analysis of this lunch menu revealed that it supplies less than 20% of the energy needs (calories), dietary fats and iron recommended even by the government’s Dietary Guidelines for a typical four-year old, let alone an older school child. It demonstrates the increasingly overzealous adoption of “healthy” diets, arising from the belief that if a little restriction of “bad” foods is good then more is better.

But unbeknownst to most parents, such diets not only have no sound evidence to support them, but they have been shown to result in harm to children’s health....

Sadly, most parents today are probably unaware of the controversy that’s raged in the medical community for more than two decades over the lack of evidence and potential harm of recommendations to restrict fats and sugars in children’s diets. [Not to mention the same situation among adults’ diets.] Let’s take fat as an example.

While there is great concern among public and private anti-obesity groups about the apparent excessive amount of fat our children are eating, that’s not what the government’s dietary statistics show. The total fat intake of kids is currently about 32%. That is well within even the 25-35% recommended for children by the 2006 Dietary Guidelines. So the tremendous energies and initiatives being undertaken to get children to eat “healthier,” low-fat diets are based more on fear marketing than facts.

Still, even the government's recommendations are controversial. While the National Cholesterol Education Program, American Academy of Pediatrics, American Heart Association and various official-sounding sources advise restricting children to 30% of their calories from fat, many health professionals have voiced concerns about both the effectiveness and safety of applying these adult recommendations to children. They believe evidence should be behind such advice.

A comprehensive examination of the evidence surrounding dietary fat for children was conducted by researchers for the American Society for Nutritional Sciences. They scrutinized the role of dietary fat in the growth, development and long-term health of children and presented their findings at a workshop held September 17–18, 1997 in Bethesda, Maryland. They found that researchers have repeatedly tried and failed to demonstrate benefits from lower fat diets beginning in childhood. Their report states that the focus on fat and the nutritional messages to limit fats are unhelpful and actual causing harm.

The disparagement of dietary fat sometimes obscures the fact that children and adults need fat in their diets.It supplies essential fatty acids and aids in the absorption of fat-soluble vitamins A, D, E and K. It is a substrate for the production of hormones and mediators. Fat, especially in infancy and early childhood,is essential for neurological development and brain function. Mother's milk and infant formula supply 40–50% of their energy as fat.

Another review of the science by researchers at the Center for Food and Nutrition Policy at Georgetown University School of Medicine, noted that low-fat diets have never been proven to be beneficial and potentially could be unsafe for children. Robert E. Olson, MD, PhD, of the Department of Pediatrics at the University of South Florida, wrote of the dietary fat obsession of public health professionals. Their “most irrational” recommendations for the population, he wrote, are those restricting fats, cholesterol and added sugars. They are to such low numbers they “in effect, eliminate a large number of foods...The goal is ostensibly to prevent atherosclerosis and cancer,” he said, but that belief has “not been demonstrated in any of the many clinical trials conducted in the United States and Europe.” His review of the evidence, published in an article titled “Folly of restricting fat in the diet of children,” concluded:

On balance, the risks of lowering the fat and cholesterol content of children diets so outweigh the benefits as to totally invalidate the recommendation of the expert panel of the NECP and the 1992 Committee on Nutrition of the AAP. Although it is clear that many children consuming diets containing 30% of calories from fat will not suffer growth failure if their energy content is adequate, the idea of promoting low-fat diets for all children without evidence of benefitwill increase the risk of malnutrition in some of them.

Since it may be possible to get sufficient nutrients with closely supervised low-fat diets, some believe that means recommendations for everyone are supportable. However, in reality, the number of cases of children not getting sufficient calories and nutrients as a result of their parents imposing low-fat diets are being reported in the medical literature with troubling and growing frequency. The concerns go beyond the risks already discussed on this site, such as eating disorders, health problems and tripling the risks for later developing obesity.

For years, pediatric specialists have cautioned:

Expert panels recommend reduction of dietary fat and cholesterol, because excessive fat intake may lead to known health hazards....The results of such diets may be suboptimal growth and development.

Since 1980, Dr. Fima Lifshitz, MD, and colleagues at the North Shore University Hospital in Long Island have been identifying children with short stature and delayed puberty, “mostly from affluent families, as a result of fears of obesity and the desire to be slim.” The parents aversion to fat was so strong that even when they were told of the need for their children to eat more, “some parents were reluctant to offer more food.”

Among children showing non-organic (no medical reason) failure to thrive, researchers find the problem is often rooted in the mother’s own fears of fat and belief in “healthy” eating. Mistakenly, the parents believe they can prevent their children from becoming fat. A study by doctors at the Park Hospital for Children in Headington, found most of these children were being fed what the parents called “healthy” diets, but which were, in fact, too low in energy and fat. Half of the mothers were restricting their children’s intake of “sweets” and another third were restricting foods they considered “fattening” or “unhealthy.”

Michael T. Pugliese, MD,Nassau County Medical Center, Division of Pediatric Endocrinology in New York, is another researcher who’s reported on the harmful effects of restricting calories and fats in children. In one evaluation with Dr. Lifshitz, nearly 10% of growth-retarded children they saw were the result of the parents fearing their children might become fat. All of these children had “deteriorating linear growth... preceded by at least 1 to 2 years of inadequate weight gain.”

Children are high energy little beings and they benefit from fats and sugars to supply all of the energy they need. Their little tummies can’t fit in enough calories eating low-fat, low-calorie foods.

But what about heart disease?

While there is no scientific evidence to support beliefs that restricting dietary fat can reduce childrens’ risks for heart disease, cancer or other chronic diseases as adults — or that childhood diets even influence adult eating habits — such beliefs continue to be popular.

Most parents would be surprised to learn that recommendations to reduce fat in children’s diets are based on findings on middle-aged men at high risk for heart disease. The few studies that have been done on children have found that a fat-restricted diet has little or no effect on blood cholesterol levels, even among children with high cholesterol. More worrisome, is that some evidence suggests these diets could pose greater risks for heart disease in adulthood.

The American Society for Nutritional Sciences’ review found no evidence linking childhood nutrition to heart disease in adulthood, for instance. They found that many of the correlations reported proved to be weak and “provide little support for drawing firm causal inferences...childhood serum cholesterol values do not predict adult levels very well.”

An additional point is worthy of note. That lunch menu recommended by Rudd Center supplied only about 1.75 mg iron, considerably less than the RDA of 10 mg for toddlers and preschoolers. It exemplifies the concerns highlighted by researchers at North Shore University Hospital, Manhasset, NY, surrounding popular fears of animal products, which often accompany fears of obesity. They found lower fat diets that avoid or severely limit animal products may not supply enough energy or micronutrients such as iron, zinc and calcium to support normal growth and development in children. Plant sources of iron are absorbed by the body at about 5%. In contrast, meat, chicken and fish (heme iron) is absorbed at 15-30%. Even though vitamin C improves absorption of non-heme iron, it is decreased by calcium-rich foods children need, such as milk. Children getting primarily non-heme iron, in the real world, are at high risk for iron-deficiency anemia.

Voices of reason

When pediatric nutrition and health experts recognized that children were not just little adults and had special nutritional concerns, Health and Welfare Canada with the Canadian Paediatric Society formed a working group to weigh the evidence. They considered children’s nutritional needs for growth and development, as well as dietary influences on adult-onset disease. They found that “there is no evidence that implementation of a diet providing 30% of energy as fat... would reduce illness in later life or provide benefit to children as children.” They noted considerable evidence showed that low-fat diets left children short on nutrients as well as calories to supply the energy they needed.

Their conclusions in a scientific statement just released this past February, were that foods should not be restricted or eliminated because of fat content during the preschool and childhood years. Only after linear growth has stopped, should adult recommendations be applied. A gradual tapering from 50% at age 2 to 30% by adulthood was advised.

This information is so contrary to everything we hear anymore, it’s no doubt unsettling to learn. But exploring all of the best evidence-based information available can only help us make the best choices for our children.

© Szwarc 2006

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