“Evidence-Based” Diets: Sound Science or Practically Impractical

May 3, 2016 by EnlightenU Nutrition Consulting, LLC 1 Comment

True or False: Popular Diets (such as Paleo, Atkins/Low carb, and Intermittent Fasting) are all based on evidence-based research.

The answer is TRUE!  There really is some interesting research that demonstrates how each of these nutrition interventions can result in weight loss, fat loss and even improved health and cognitive functioning.

But, does that mean these diets should get a “seal of approval” as an appropriate intervention for weight loss or achieving optimal health?  Let’s chat about that…

Recently I watched a TED Talk by the Chief of the Laboratory of Neuroscience at the National Institute on Aging, Mark Mattson. He is also a professor of Neuroscience at The Johns Hopkins University and a leading researcher in understanding the mechanisms behind neurogenerative disorders, such as Parkinson’s and Alzheimer’s disease. Mark and his team from John Hopkins have published several papers that discuss how fasting twice a week could lower the risk of developing these types of neurogenerative diseases.

Pretty impressive, right? I mean that’s a big deal!

Then, there’s The Paleo diet, based on years of research conducted by Loren Cordain, PhD who bases his nutrition recommendations on the premise that there are some fundamental characteristics of our hunter-gatherer ancestors that will “optimize your health, minimize your risk of chronic disease and lose weight.”

I’ve also been learning more about the research behind Intermittent or Alternate Day Fasting (restricting intake to no more than 500 calories every other day) and the significant effect it can have on weight loss and other markers of health. Some of the most notable work on this approach has been done by research from the University of Illinois in Chicago.   And, of course documented in the popular book, The Every-Other-Day Diet: The Diet That Lets You Eat All You Want (Half the Time) and Keep the Weight Off.

What a great idea! Pretty much every individual I work with – midlife female, recreational or competitive athlete, professional dancer, or disordered eater – would like to optimize their health, lower their risk of chronic disease, most desire to lose weight, and would prefer the option of being able to “eat all you want” – even if it is only half the time.

And, of course, there’s all the latest research coming from the labs of Dr. Stephen Phinney, MD, PhD and Dr. Jeff Volek, PhD, RD about the “Art and Science of Low Carb Diets.”

Well, if you know me, you know that I LOVE science and am fascinated by research. I’m constantly digging into the latest literature in popular scientific journals or looking up supporting research on Pubmed about various topics in nutrition and beyond.

My question is always, “Why?”…Why do things work the way they do? Why are midlife women gaining weight when seemingly nothing else has changed? Why do some athletes perform better than others? Why doesn’t energy in = energy out for most of my clients?

Ultimately, I want to know: “What’s the best solution to the problem?” and “What will be the most effective nutrition intervention for my client?”  

So inherently research should be able to give us the answer – right?  Well, not entirely. Yes, we learn a lot from this research and the science can be extremely fascinating, but there are a number of problems with these diets that potentially cause more problems than what the dieter started with.

The use of evidence based medicine is important in any clinical practice – including nutrition. However, after working with 100’s of individuals who have gained and lost hundreds of pounds from these “evidence based” diets; who often know enough about nutrition to have a degree themselves; and who ultimately continue to struggle with food, eating and weight, I’ve learned that clinical judgement and practical application are critical to an appropriate and effective nutrition recommendation.

And, as obvious as that may seem, it’s very interesting how often folks (including well-meaning researchers and providers) get enthralled with the “science” and seem to miss asking an important question of “how will this recommendation work out in the long run for this individual?” and ultimately whether the application of this “science” is even practical.

Remember:  Clinical judgement is something you don’t learn in school, from an online course, or from reading Pubmed articles. It is something you learn in practice!

In fact, we are reminded in an editorial about Evidence Based Medicine: What it is and What it Isn’t, that “Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients.”  In other words, it’s important that researchers and clinicians work together to develop realistic, practical and do-able approaches to health and well-being.

As an illustration of this point, let’s take a look at just 5 reasons why it might be “practically impractical” to use an intervention like Intermittent or Alternate Day Fasting.

Problem #1:  This is not normal eating. Rigid diets that rely on counting and restricting calories is just plain and simple disordered eating. At the very least, the majority of dieters will not be able to sustain this plan for the rest of their life (ultimately sustainability is important, right?). Many will likely suffer guilt and shame when they go over their 500-calorie limit; and consequently continue the cycle of dieting that, research has demonstrated, leads to even more weight gain, depression and a worsened health condition. There’s a lot more we could say about this point, but hopefully you get the gist.

Problem #2: How do you sustain your mental stamina, focus and not suffer from dizziness on a 500-calorie day?  The researchers state that your body “gets used to it” and you aren’t hungry on the fasting days. In a study published in the Journal of Nutrition looking at the  effect of alternate day fasting (ADF) on disordered eating behaviors, researchers noted that “Subjects undergoing ADF experienced mild gastrointestinal issues, occasional problems with staying asleep, and minor dizziness/weakness.” Bad breath seemed to be the most annoying symptom to which it was recommended for dieters to chew sugar-free gum in between meals. It’s also important to note that 20% of the study subjects dropped over the course of the 8-week study.

I just want to stop for a moment and remind the reader that tax payer dollars from the National Institute of Health are funding much of this research as an effort to “improve our health.”

Problem #3: How can an individual participate in stress-relieving, mood-stabilizing exercise on a regular basis, especially on a 500-calorie day? Researchers have a recommendation for that too. They suggest that the dieter get exercise or activity out of the way in the morning on the fasting days. What if you are an afternoon or evening exerciser – because of work, responsibilities, or that’s just what you prefer? Also, I’m a pretty active person who enjoys my exercise in the morning, but then I might also work in the yard for a few hours after lunch or I stay active running from appointment to appointment. It’s not an option for me to just “plop” for the rest of the day – nor do I want to or recommend as a solution!

Problem #4:  How does the dieter manage social events on the 500-calorie day? I’m guessing that if you tried to implement this plan consistently; at one time or another, you are going to have an event with food like a grad party, wedding, birthday party, work event, gala, etc on the calorie-restricted day. Are you just supposed to abstain from eating at these events? If the answer is yes, that’s unfortunate. And, if you decide to throw in an exception here or there, how’s that going to work in the long run? I know for most of my clients who are trying to make behavior change, not learning how to navigate these kind of events is many times the reason for sliding into old behaviors.

Problem #5: Eating doesn’t need to be this difficult. In a small, non-scientific survey I completed with a number of individuals of various ages, not one person thought they could (or would want to) implement this diet consistently. A common response was that it “sounded like a lot to think about” and they “weren’t sure they could keep the days that organized”.  I have plenty of clients who are just fine with the feeling of control they get from counting calories, but even these folks admit it’s distracting and a very compulsive and obsessive behavior, and frankly would rather not to have all those numbers in their head.

I’m completely aware that there is always the possibility that none of these scenarios would pose a “problem” for you. If that’s the case, and this sounds like a useful approach for managing food, eating and weight, then it may certainly be an option.

Ultimately, the decision about what nutrition intervention would be best for an individual hoping to lose weight, optimize their health and decrease their risk of chronic disease needs to be a collaborative effort between the health care provider and patient.

Being fascinated by science is a cool thing. And, providing sound, evidence-based nutrition recommendations is an important principle in any practice. But, science alone should NOT become a replacement for critical thinking and experienced clinical judgment about what is appropriate for each and every individual client or patient.