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Royal Academy of Nutrition and Health Eating

26. What’s the Real Deal When It Comes to Nutrition Research and Advice?

If you “Google” the word nutrition, you will get a list of about 103,000,000 entries in 0.25 seconds. Obviously, the world is full of nutrition information. Just ask anyone who is trying to lose weight and that person will probably tell you how hard it is to keep up with the latest diet advice - because it seems to keep changing. In the 1970s, waist watchers were told that carbohydrates were the bane of their existence and that a protein-rich, low-carbohydrate diet was the name of the game when it came to shrinking their waistlines. A decade later, avoiding fat was the key to winning the battle of the bulge. By 2000, carbohydrates were being ousted yet again, and protein-rich diets were back in vogue. But now protein-heavy diets seem to be fading out of the limelight and higher carbohydrate diets - with plenty of fiber - are becoming the way to fight weight gain. So . . . are you frustrated yet?

Even though popular wisdom and trends seem to change with the wind, scientific knowledge about nutrition doesn’t change this frequently. While the media publicizes results from studies deemed newsworthy, in reality it takes many, many affirming research studies before a consensus is reached about nutrition advice. News of the results of one study is just that: news. In contrast, advice from an authoritative health organization or committee, such as the American Heart Association or the Dietary Guidelines Committee, which is based on a consensus of research information, is sound information that can be trusted for the long term. Headlines in newspapers, lead articles on websites, and the sound bites on television often report the results of a single, recent research study.

The boxed feature “Evaluating Media Headlines with a Critical Eye” discusses how to scrutinize information about current research findings and not get caught up in the media hype.


Consensus: The opinion of a group of experts based on a collection of information.


27. Sound Nutrition Research Begins with the Scientific Method

Research studies that generate enough information are based on a process called the scientific method. Scientists are like detectives. They observe something in the natural world, ask questions, and come up with an idea (or hypothesis) based on their observations, test their hypothesis, and then see if their idea is correct. There are many steps in the scientific method and many adjustments made along the way before a scientist has gained enough information to support his or her hypothesis. In fact, the entire process can take years to complete. Let’s walk through a nutrition-related study in which scientists used the scientific method to study rickets. Rickets is a potentially severe and even fatal disease in children, whereby the bones throughout the body weaken. For instance, the spine and rib cage can become so distorted that breathing is impaired. The leg bones can become so weakened that they are unable to hold up the child’s body weight, and they curve outward (“bow legs”). In the nineteenth century, parents often relied on folk remedies to treat diseases; in the case of rickets, they used cod-liver oil because it seemed to prevent the disorder as well as cure it, although no one knew how. The first steps of the scientific method are to make an observation and ask questions. Originally, scientists were piqued by the cod-liver oil curing phenomenon.

They asked themselves why cod-liver oil cured rickets. In the second step of the scientific method, a hypothesis is formulated. Because cod-liver oil is very rich in vitamin A, scientists initially thought that this vitamin must be the curative factor.

To confirm this, scientists proceeded to the next step in the scientific method, which was to conduct an experiment. The scientists altered the cod-liver oil to destroy all of its vitamin A. The altered oil was given to rats that had been fed a diet that caused rickets. Surprisingly, the rats were still cured of rickets. This disproved the scientists’ original hypothesis that vitamin A was the curative factor. They then needed to modify their hypothesis, as it was obvious that there was something else in the cod-liver oil that cured rickets. They next hypothesized that it was the vitamin D that cured the rats, and conducted another experiment to confirm this hypothesis, which it did.

The next step in the scientific method involves sharing these findings with the scientific community. What good would it be to make this fabulous discovery if other scientists couldn’t find out about it? To do this, scientists summarize and submit their research findings to a peer-reviewed journal. Other scientists (peers) then look at the researchers’ findings to make sure that they are sound. If so, the research study is published in the journal. (If this relationship between vitamin D and rickets was discovered today, it would probably be the lead story on CNN.)

As more and more studies were done that confirmed that vitamin D can cure and prevent rickets, a theory developed. We now know with great certainty that vitamin D can prevent rickets and that a deficiency of vitamin D will cause this type of deformed bones in children. Because of this, there is a consensus among health professionals as to the importance of vitamin D in the diets of children.


Scientific method:  A stepwise process used by scientists to generate sound research findings. The scientific method is used to conduct credible research in nutrition and other scientific fields.

Hypothesis:  An idea generated by scientists based on their observations.


28. Evaluating Media Headlines with a Critical Eye

Based on this headline, you may be tempted to run out immediately and get yourself a couple of chocolate bars. However, you would be doing a disservice to your health if you didn’t read below this tantalizing headline, to assimilate and analyze the evidence on which the headline is based.

The media are routinely bombarded by press releases sent from medical journals, food companies, organizations, and universities about research being conducted and/or conferences being sponsored by these institutions. These releases are sent for one reason: to gain publicity. Reputable news organizations that report these findings will seek out independent experts in the field to weigh in on the research and, just as importantly, explain how these findings relate to the public. If you don’t read beyond the headlines, you are probably missing important details of the story. Even worse, if you begin making dietary and lifestyle changes based on each news flash, you become a scientific guinea pig.


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29. Research Studies and Experiments Confirm Hypotheses

Scientists can use different types of experiments to test hypotheses. The rickets experiment just described is called a laboratory experiment, as it was done in the confines of a lab. In the fields of nutrition and health, laboratory experiments are often conducted using animals, such as rats. Research conducted with humans is usually observational or experimental.


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31. What Is Nutritional Genomics?

As we learn more about nutrition from ongoing research, we are likely to find even more ways in which what we eat affects our personal health. One exciting area of research now is nutritional genomics.


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