Beyond the Headlines

Sorting Out Nutrition Science

As sports dietitian—a registered dietitian who specializes in sports nutrition—not a day goes by that I’m not dealing with science: biology, biochemistry, physiology, exercise science, medicine, nutrition ... the list goes on and on.

As a runner looking to improve your performance, you too need to deal with the science. No, you don’t need to make a career out of it, but learning how to interpret and make sense of scientific information that impacts your daily eating and training habits is imperative. Otherwise, you are doomed to worrying needlessly about every "breaking" nutrition and health-related story, as well as to falling victim to erroneous advice about supplements and fad diets.

Understanding the Scientific Process

To the non-scientist, diet and health-related scientific news is often frustrating. Almost daily, we read or hear about what appears to be contradictory information about performance-enhancing supplements or the best diet to follow. Do carbohydrates give you energy or do they really make you fat? Should runners be following the classic high-carbohydrate, low-fat, moderate-protein diet (and what is high carbohydrate by the way—55% of your total calories, 60%, 70%?) or would eating more protein and fewer carbs help us drop those last stubborn pounds and pick up some new PRs? Will a pill a day give us more energy?

The scientific process—how studies are designed, conducted and reported—is a road of discovery, a road that is not necessarily straight. Spend an evening with a group of runners describing the ideal training schedule for a marathon or what constitutes the "best" running shoe and you have the idea. The scientific process hinges on gaining knowledge about a subject through observing measurable evidence. To uncover facts, researchers often need to explore in different directions, causing the road to twist, turn and sometimes even backtrack. As is often the case with food and health-related information, these facts may still be only part of a larger, partially understood phenomena, thus requiring even more research be conducted before answers can be found. The refrain "two steps forward, one step back" is common in the scientific world.

As a result, the scientific process generates a great deal of debate. Tracking the debate, which can take considerable time and effort, is the key to putting new research into context.

First, new findings as published in scientific journals should be viewed as discussions among scientists. Almost no one gets the final word in these discussions, as it’s rare that any one study provides a final, complete answer. In other words, researchers publish their results (the gold standard is in a peer-reviewed journal) expecting that debate will ensue. Other scientists trying to duplicate the results will confirm or contradict the results. This process is crucial in adding to the body of literature on a subject as well as in shaping future research.

Second, keep in mind that certainties only emerge through repeated research and analysis—like a runner having to try out several sports drinks before finally settling on one that works consistently. Coming up with certainties for an entire population as a whole (e.g., the ideal sports drink for all runners) takes even more time and effort. It’s also possible that old, accepted research results will be revisited and discussed again and even seen in a new way as new information or technology comes to light.