It seems that nearly every week, a new study on nutrition comes out that contradicts the latest health trend. Eggs are nutritional miracles; eggs are cholesterol-laden artery constrictors. Fat is the number one weight-loss enemy; fat is the key to weight loss.
Why is nutrition advice so contradictory and ever-changing? In a word, research. In theory, good science and research is driven by hypotheses, ideas, and concepts that need to be proven or disproven. It should be simple. But in nutritional science, that is rarely the case.
Here are some reasons why research on nutrition can go so far awry, and how to know what information to trust.
Not All Studies Are Created Equal
The quality of a study is influenced by many factors. Here are some of the big ones:
Good-quality research can be hard to apply to nutrition questions. Unfortunately, the most reliable research methods are difficult to apply to many questions about what constitutes healthy eating.
Randomized controlled trials are considered the most accurate way to gather evidence in medicine. These involve groups of participants who are selected randomly and then divided into two groups: the test group and the placebo (control) group. The idea is that since the participants were randomly selected, any difference in the results will be because of the treatment.
Problems applying information from animal research to human health are inevitable.
However, many such studies are done over a period of only weeks or months, meaning they don’t reflect real life or how a particular dietary choice might impact the body over decades. There will always be a gap when research relies on short-term studies for answers on chronic, long-term issues.
It’s also not practical, and possibly unethical, to do the types of nutrition studies that would lead to the most accurate results—for example, locking people up and observing every meal they eat for 25 years, sequestering newborns for testing, or repeatedly feeding subjects unhealthy food to see how their bodies react. read more…