How to Understand All of Nutritional Science – with Marc David

Have you noticed that there’s an abundance of well regarded nutrition experts with dietary systems and approaches that are vastly different –  and yet they have scientific validation and a lot of passion to back it all up? Have you ever been frustrated by these contradictory messages, and wished you had some clarity and some answers? Join Marc David, founder of the Institute for the Psychology of Eating in this informative and uplifting video blog – “How to Understand All of Nutritional Science.” You’ll come away with a renewed understanding of the complex field of nutrition, and perhaps you’ll be able to relax a little and smile as you empower yourself with some fresh insights and information.

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In the comments below please let us know: How do you empower yourself when you hear contradictory nutrition information from the experts? We love hearing your thoughts!

Here is a transcript of this week’s video:

Greetings friends, this is Marc David, founder of the Institute for the psychology of eating

Today’s topic: How to Understand All of Nutritional Science

That sounds like a pretty big promise doesn’t it? When I think about it, it really is. But I’ll do my best to make good on that promise. In five minutes or less, I’m going to outline some important and fundamental distinctions that will help you look at the science of nutrition, and all the information that you’re constantly exposed to – in a whole new way. You’ll have more insight, clarity, less confusion, and a greater sense of empowerment. In fact, you’ll probably have more understanding of the field of nutrition in the broadest sense than many experts in the field.

Let’s get going.

First, let’s take a big picture look at the field of nutrition:

  • It’s the wild west
  • It’s a young science – meaning nutrition is still developing, and we still have our training wheels on when it comes to truly understanding the depth of the nutritional process
  • Experts disagree – and it’s okay
  • For every PhD, there’s an equal and opposite PhD – meaning we will always always always find opposing viewpoints – even when you’re not looking for them
  • No field in Science operates with universal agreement – that’s just the way it is. You need to build up your tolerance for disagreement
  • Scientists can be very passionate, very religious, and very dogmatic. Scientists are just like you and me – they’re human beings. Be patient with them, love them, thank them for their hard work and their passion, and please don’t be intimidated by them!

Nutrition is vastly influenced by personal preference – by fallible scientists. When I was in college in the 1970s I interned at Sloan-Kettering Cancer Institute in New York City. I was very fortunate to be working on the most famous floor in their research laboratories. Every scientist on this floor was a well-known name in cancer research. It was an exciting time for me, I learned a lot, and I had the opportunity to be up close and personal with how some great scientific minds truly work. There was one particular scientist who I would run errands for who especially took a liking to me. He was fascinated by all the strange foods that I would eat – I’m talking about sprouts on my salad, seaweed, odd looking organic dried fruit from the health food store, and my green drinks. Actually, he was less fascinated and more amused, and he truly thought I was a nutritional buffoon, and he had no hesitation to tell me so. He was convinced that food had little to no effect on your health, and that any scientist who was studying the role of nutrition in cancer was wasting valuable money and resources. What I love the most about him was that he would pontificate about all of this while drinking about seven or eight Diet Cokes every day. He was addicted. I could tell when he was coming down off of his Diet Coke. He’d get moody and irritable and forgetful. I’d have to go into the lobby and get another can of Diet Coke from the machine. Think about it for a moment – he had a personal relationship with food, and personal beliefs about it that dramatically impacted – and limited – his scientific approach.

Back to our important distinctions to help us understand all of nutritional science:

Today’s nutrition facts are often tomorrow’s fallacies – in other words, many of the nutritional injunctions you hear about likely have a brief shelf life. We used to think margarine was good for you. We thought sugar was safe. We thought that high carbs and low protein and fat was the best diet to follow. We thought that it was okay to put artificial colors in food. We thought that all protein was the same, and all fat was the same. So it’s probably helpful to not get too attached to whatever nutritional facts you believe are immutable and permanent and applicable to all people for all time.

Understand this: Humans are still growing and evolving – and so is our nutrition. So it makes perfect sense that science will continue to change because the universe, the solar system, the earth, and all its creatures and organisms are in a fantastic state of flux and unfoldment.

Next, it’s also quite useful to note that innovation in the field of nutrition often comes from the outside. Meaning, most of what you practice when it comes to what you eat and the healthy foods that you purchase didn’t originate in some high-end scientific laboratory or in the hallowed halls of an Ivy League school. Nutrition and dietary innovation is largely a grassroots affair. Think of these examples – macrobiotics, the Atkins diet, the Mediterranean diet,  the Pritikin diet,  the zone diet, the Paleo diet, veganism, raw foods, cleansing programs, orthomolecular nutrition, the use of supplements and herbs – all of these were brought to you by outsiders, some through ancient wisdom, some from people who have no formal university and scientific education, and some from doctors and experts who were considered to be on the quack-like fringe.

So here’s the bottom line:

There’s a whole spectrum of nutritional systems that can work for people depending on their age, their health, genetics, environment, season, preferences, lifestyle, cultural preferences, and so much more…

The perfect diet likely does not exist, and it’s always a moving target in terms of what works best for any one person at any time.

So, relax into the uncertain turf of nutrition.
Do your best to be okay about living in uncertain times.
Let the evolution of nutrition be what it is.

Stop moaning and groaning that everybody says something different when it comes to the best nutritional approach.

Welcome the craziness of it all, celebrate it, smile at it, contribute your two cents to any argument, and have yourself a meal that feels good.
I hope this was helpful, my friends.

To learn more about us please go to

The Institute for the Psychology of Eating offers the most innovative and inspiring professional trainings, public programs, conferences, online events and lots more in the exciting fields of Dynamic Eating Psychology and Mind Body Nutrition! In our premier professional offering – the Eating Psychology Coach Certification Training – you can grow a new career and help your clients in a powerful way with food, body and health. You’ll learn cutting edge skills and have the confidence to work with the most compelling eating challenges of our times: weight, body image, overeating, binge eating, digestion, fatigue, immunity, mood and much more. If you’re focused on your own eating and health, the Institute offers a great selection of one-of-a-kind opportunities to take a big leap forward in your relationship with food. We’re proud to be international leaders in online and live educational events designed to create the breakthroughs you want most. Our public programs are powerful, results oriented, and embrace all of who we are as eaters – body, mind, heart and soul.

Please email us at if you have specific questions and we will be sure to get back to you.

Again that is

This is Marc David, Founder of the Institute for the Psychology of Eating.

Thanks so much for your time and interest

In the comments below please let us know how do you empower yourself when you hear contradictory nutrition information from the experts? Marc personally reads every comment and does his best to respond. We love hearing your thoughts!


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  • Brilliant statement. So true, Mark – “For every PhD, there’s an equal and opposite PhD – meaning we will always always always find opposing viewpoints.” Thanks for this wise post.

    • Hi Julie,

      So glad you connected with that!

      Thanks for reaching out…


  • Carla

    Hi Marc
    First of all thanks for your brilliant work and insights. It is eye opening and refreshing!

    Keeping in line with the confusion surrounding contradictory information from experts I was wondering about your insights about the weight ‘set point’… i.e. the theory that the set point is the weight range in which your body is programmed to weigh and will fight to maintain that weight?

    • Hi Carla,

      Thanks for watching! I’m glad that you enjoyed the video. The set point theory simplifies various complex factors that are in play to allow the body to maintain homeostasis. There are numerous hormones that are secreted when the body loses weight too quickly that are secreted to try and keep the weight in a set range. This is one of the many reasons why slow and steady wins the race.

      I hope that helps!

      Marc David

  • There is another reason for all of the confusion around nutrition. All studies of nutrition are illness based. We don’t study the ‘health’ of nutrition (without reference to illness) and we have no idea where to start.

    When all studies are illness based, it makes sense that results will be contradictory. Results can only be published when an illness is involved. Published research presents a very distorted view. I challenge anyone to find published research about HEALTH, that does not reference illness. Health is whole, illness is a hole in your health. Our so called ‘nutritional science’ is the study of holes, not the study of health. The closer you look, the worse it gets. Many of our ‘foods’ are specifically designed and grown to be ‘unhealthy’. Unhealthy plants and animals grow faster, cheaper, and are less likely to spoil – because healthy animals avoid them.

    When we combine this with the simple fact that any nutrient can cause illness in excess, and many nutrients can cause illness when deficient – you have a recipe for nonsense. I don’t think we should relax, we need to wake up.

    • Hi Tracy,

      Great points – right on the money…
      I’ve been on this one for a long time.
      I love your line: “I challenge anyone to find published research about HEALTH, that does not reference illness.”
      I also agree we need to wake up big time, and for me, part of waking up for so many people is relaxing into listening to your own body’s needs, while letting go of the stress that so many people experience around nutritional confusion.

      Thanks for reaching out and sharing your excellent insights…


  • John Burke

    Hi Marc – my approach to the avalanche of conflicting data has been to try and consolidate a core consensus of agreement-
    For example:
    -Exchanging grains and beans for more greens
    -Garlic powder, Cayenne powder, Ginger powder, and Turmeric powder are highly anti-inflammatory
    -The importance of the endothelial lining and nitric oxide

    Then I watch for cutting edge confirmations, etc. – always striving to ensure that the core gets more and more solid-
    -Turmeric research all positive
    -A recent questioning on pure organic aloe vera juice noted by Michael Greger

    Marc – what is your personal take on Dr. Esselstyn’s “no oil” approach
    and Monica Reinagel’s anti-inflammation formulation?
    Definitely worth your valuable time and attention-
    The overlapping foods agreeable to both approaches makeup quite a solid core array

    Thanks Marc

    • Hi John,

      It sounds like you’re doing some excellent research – bravo! I’m not familiar with Dr. Esselstyn’s “no oil” approach or Monica Reinagel’s anti-inflammation formulation. I will check it out when I have some time – which isn’t much these days.
      Thanks again for your insights…



  • Committed/Nutritionist/Vegan

    Thanks you Marc, for referencing this from one of my postings on one of your recent videos!!!!!

    As “seekers of truth”/we are conditioned to seek “the Way/the Truth/and the Light!!!!”/We want THE Ten Commandments of Nutrition/So help me God!

    There are times, in fact, that as the saying goes: WWJD, I think we should, perhaps, in fact, consider what Jesus ate/or would eat, especially if he knew what we now know/Ethically/Environmentally and for our health/the way OUR bodies are designed/and compared to other primates/Large Mammals

    While i have been exposed to nutrition for 50 years/it is interesting/what with all the science….We put a Man on the Moon/ it is considered in its infancy.

    As you indicated, Discovery is exciting. And as I like to say/and I do think it is generally quite true: “We are each an experiment of one.”

    If it sounds reasonable, based on ones knowledge, give it a try. If it works, run with it. If not, for heavens sake stop!!! Insanity is expecting different results while repeating the same behavior!!!!

    Again, thank for this GREAT video/and for all the work that you and Emily do on behalf of ALL sentient creatures here on earth. Your efforts are needed now more than ever; and with the projections I have seen/heard about/in India and China for example/your efforts will be needed even more so as the decades ahead of us unfold.

    May God Bless you and yours throughout this Holiday Season and through and beyond the fresh New Year that is about to present itself to us.

    David K.

    • Thanks for sharing your thoughts David. Best wishes to you in the New Year! Warmly, Marc

About The Author
Marc David

Marc David is the Founder of the Institute for the Psychology of Eating, a leading visionary, teacher and consultant in Nutritional Psychology, and the author of the classic and best-selling works Nourishing Wisdom and The Slow Down Diet. His work has been featured on CNN, NBC and numerous media outlets. His books have been translated into over 10 languages, and his approach appeals to a wide audience of eaters who are looking for fresh, inspiring and innovative messages about food, body and soul. He lectures internationally, and has held senior consulting positions at Canyon Ranch Resorts, the Kripalu Center for Yoga and Health, the Johnson & Johnson Corporation, and the Disney Company. Marc is also the co-founder of the Institute for Conscious Sexuality and Relationship.