What Do We Really Know About Diet And Exercise?

Every month I consume over 100 professional journal articles, magazines, books, emails, blog posts, and podcasts in the health, wellness, fitness, rehab, nutrition, and related fields. I do this because it is one of my major interests and relaying accurate information on these topics to my clients is my job. Because diet and exercise, in particular, are some of the most media-intensive, fad-driven, marketing-hyped topics in our world, I’m sure you see much of the same data. It is sometimes difficult to sort fact from fiction, and this challenge was recently highlighted by an article in The New York Times.

The article, by Gina Kolata, entitled “We’re so Confused: The Problems With Food and Exercise Studies”, described the difficulty that exists when trying to sift out accurate information in the fields of diet and exercise. We are in the midst of incredible times as truly brilliant work is being done. Research and theory are literally pouring into our presence and inundating our communication mechanisms. And much of it is contradictory.

One of the first things to understand is the difference between correlation and causation. In correlative studies, associations are identified, such as between the consumption of a food product like carbs, fat, meat, blueberries, etc., and markers of bodyweight, blood sugar, blood pressure, longevity etc. (you get the picture – it’s a busy one). A major shortcoming of any correlative study, particularly regarding nutrition, is dietary recall. Even when study designers or participants are well-meaning, how does anyone remember exactly what they ate a week ago.? And many of those studies don’t use daily recording and analysis of intake. For data to be evidence-based, causation needs to be shown. Very few studies have been done where people are locked into a hospital ward for 3 months and their intake/output is measured intensively. Additionally, a study on mice with an N of 5 just doesn’t quite allow us to make the leap to assume causation in humans. More randomized controlled trials are being done every day, but we have to view them with a discerning eye.

This brings us to consider funding. Research isn’t cheap, and adequate monies are required to produce experiments. The challenge is that much of the food-related studies are industry-driven, or funded, and when a study is funded by, for example, a producer of GMO corn, it is 8 times more likely to show a favorable finding that one funded by an impartial, outside source.

Then we get to the uniqueness of the human condition. It is a dynamic, multifactorial existence that is ever-changing and adapting. Few would disagree with this point. But when we attempt to isolate one dependent variable, which is necessary in most experimental design, we can get into trouble. Researchers have to be careful in saying that, based on a study’s results, that (again, an example), eating a certain food causes disease. In reality, our movement habits, our stress levels, our sleep patterns, our specific genome, and our other food intake all inter-relate and affect the outcome of any given health variable.

As rational and collaborative beings we need to agree on several points: We don’t and never will know everything, and we don’t always have to agree. Having stated this, I should point out that we have great data coming in and moving toward consensus on many health topics. But every person is both similar and unique, and there is room for individual interpretation and application with any health practice. Our genetics, our personalities, our cultures, our body types, and many other things drive these differences and can help us to understand how, within general categories, one dietary practice or exercise habit might get a little better result with one person than another.

We need to remind ourselves to be good consumers of health advice with the proper mix of hunger for knowledge, and respect/class/tact when dealing with service providers, colleagues, family, and friends. Right now, we are seeing several topics being turned upside down by good science. Cholesterol is no longer a nutrient of concern with respect to heart disease. Polyunsaturated oils may not be as good for us as saturated fats. Calories may not matter as much as we once thought. Excessive carbohydrate intake is in part related to our illness/diabesity epidemic. Inflammation management is the key to disease prevention/treatment and is accomplished by balancing hormones and managing metabolism (and this is easily, yes easily, done with simple lifestyle practices). We probably don’t need as much official exercise for health benefits as we once thought, and we should really just move more. But when we work out, it should be (in a safe manner), briefer and more intense that what we once thought.

There are many more of these conflicting, but indeed interesting changes going on RIGHT NOW in not just the diet and exercise world, but in health, wellness, success, and happiness subject areas. They are indeed inseparable. While this may have been a bit of a rant, I’m not sorry about it. I’m passionate about it. I will only provide you with authentic information, whether reviews of cutting-edge brand-new science, or original work of my own. Take everything you see, hear, and read with a grain of salt (yes, pun intended), preferably sea salt or Himalayan pink salt. Even if it comes from me.

Share a comment or question!

This site uses Akismet to reduce spam. Learn how your comment data is processed.