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Good diets promote good health, but diets are composed of nutrients which are consumed as foods. SI technical director Mort Satin explains why it's important to consider the whole diet -- both for individuals and public health nutrition policy-makers in the latest number of Salt and Health.
I recall an old colleague of mine in the United Nations who kept a sign on the wall behind his desk,
“Don’t Just Do Something, Stand There!”It was his way of trying to get people to think things through thoroughly, before rushing headlong into an intervention.
Legislation on food labeling, recommendations on Daily Values and the Dietary Guidelines are all examples of interventions that would have benefitted from my friend’s advice. About the only thing that everyone can agree upon is that they are all largely ineffective and hold scant benefit for the consumer.
In a recent article entitled, “A Call for Higher Standards of Evidence for Dietary Guidelines,” Am J Prev Med 2008: DOI: 1016/j.amepre.2007.11.017., authors Marantz, Bird and Alderman make the case that with their weak standards of evidence and tendency to focus on individual nutrients, the national dietary guidelines might actually do consumers a lot more harm than good.
As an example, they used the guidelines developed against the consumption of dietary fat, promulgated in the late 1970s. The authors noted that people were inadvertently led into believing that if they limited their fat intake, they could then go ahead and pig out on carbs - a phenomenon which may have contributed to the current epidemic of obesity and overweight in the U.S.
The flaw in reasoning was that no one believed that the guidelines could cause any harm, therefore only the weakest evidentiary support was needed to promulgate them. Indirect evidence, expert opinions and scientific “reasoning” were the main drivers of the guidelines. After all, they were only guidelines – what could be so bad?
In fact, once published, they took on an aura of credibility that far exceeded any scientific justification. Once promulgated and given the blessing of the medical establishment and the government, they were looked upon by the public, by the media and by teachers no differently than if they had been irrefutably proven by the most rigorous scientific experimentation. And government guidelines don't simply affect one or two of us - we are all influenced by government guidelines.
The authors write that in 2000, the Dietary Guideline Advisory Committee reversed an earlier 1995 recommendation to lower fat intake, indicating that it may have been premature and ill-advised. The Committee stated that "an increasing prevalence of obesity in the United States has corresponded roughly with an absolute increase in carbohydrate consumption."
Marantz et al also point to the advice given on salt intake as another example of the unintended consequences of a seemingly innocuous recommendation, noting that any blood pressure benefits may be trumped by the stream of harmful effects on plasma renin, insulin resistance, sympathetic nerve activity, and aldosterone levels. They further point to a recent finding of no difference in total mortality between randomized sodium-intake groups.
The authors final conclusion for a dietary guideline recommendation reminded me of my dear old friend;
“When adequate evidence is not available, the best option may be to issue no guideline.”
Almost 30 years after the UN International Year of the Child , 2008 is shaping up to be a banner year focused upon improving the health of our children through the provision of nutritional information and recommendations for improvements to their lifestyle.
It seems a bit odd to be referring to lifestyle improvements for children; after all, don’t children do what they’ve always done?
Wrong!
The lifestyles of children have changed dramatically and most of these changes are not positive for their health. Eating a breakfast bar during the morning bus commute to school is OK but it is not the same as sitting down at the kitchen table, having breakfast and then marching off to school. Playing the Wii game for a few hours a day in front of the widescreen is a lot of fun, but it is not the same as running your heart out chasing a soccer ball. Not the same for a child's mind nor a child's body.
Having a pizza delivered, with double everything and cheese product extruded into the crust might be great to order one night, but unless someone insists that everyone take a 5 km run afterwards, the extra calories have only one unflattering place to go. Do that or something similar a few times a week and you are beginning to talk about some pretty serious caloric and nutrient imbalances.
Maybe referring to children’s lifestyle issues is not such a bad idea, after all.
The recent GMA Industry Health and Wellness Report highlights the goal of reducing obesity rates and encouraging healthy lifestyles for children. Not only do children have to be encouraged to pursue a fully balanced diet as shown in MyPyramid, but they should be taught the simple concept of energy balance and encouraged to do far more aerobic physical activity to keep their weight in check and their metabolic processes toned up.
In a recent paper entitled, “Children's diets: looking at the bigger picture”, Charlotte Musgrove, a nutrition scientist at the British Nutrition Foundation in London states that previously, the main focus was to provide enough energy and nutrients to meet the needs of a growing child. However, today there is a stronger emphasis on making sure that children are having a varied and balanced diet, and an active lifestyle. Of particular interest, is the finding that the message to eat at least five portions of fruit and vegetables a day appears to be gaining ground. Although many children are still not consuming the recommended amount of fruit and vegetables, their intakes have increased over recent years. In 2000, children were on average eating only 2 portions of fruit and vegetables a day. One in five children did not report eating any fruit, and three in five children did not report eating any green leafy vegetables over an average week. Between 2001 and 2004, average intakes of fruit and vegetable portions per day increased slightly, with boys consuming 2.5 portions per day, and girls consuming 2.6. Data from 2005 shows the average number of daily portions of fruit and vegetables eaten was 3.1 (for both boys and girls) and there was an increase in the proportion of children eating five or more portions per day (Health Survey for England 2005). Good news, but still a long way to go.
Together with the balance of nutrients from the rest of the diet, with physical fitness programs to ensure their bodies are kept in tune and a social environment where they can flourish with support and mentoring, our children will thrive in good health.
Slowly, slowly, we are moving away from the single, silver bullet solutions to children’s health problems, because although they seem easy and they have made many rich and famous – they don’t work – they never have. Life is just not that simple. It’s the whole diet as part of the whole lifestyle that will direct us to good health for our children.
Everything should be made as simple as possible, but not simpler - Albert Einstein
Anyone promoting the addition or reduction of any single nutrient as the key solution to children’s diseases is little different from the snake-oil salesmen of days gone by.
The problem is, they sold an awful lot of the stuff.