When You Eat is as Important as What You Eat

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Rhythm is everywhere. Each particle of our being moves and pulsates, dances and sings, and keeps to the beat of a brilliantly conceived symphony. The whole of our biology is a fantastic clockwork of precise chemical and hormonal rhythms whose timing is critical for our survival and well-being. Your heart beating is a rhythm. Your lungs breathing, inhaling and exhaling vital atmosphere, is a rhythm. The electrochemical pulsation of the brain is a rhythm. So too is the menstrual cycle, waking and sleeping, digesting and eliminating, and the contraction and expansion of every cell, vessel, and organ in the body. Interfere with any of these and disease or death can follow.

Master rhythm and you master metabolism.

Indeed, much of what ails us from a nutritional perspective – weight gain, fatigue, digestive complaints, carbohydrate craving, overeating – can be resolved by entraining with the kinds of rhythms that naturally and effortlessly regenerate us. Lets take a look at how we can better understand and harness this important metabolic force.

One of the simplest and most reliable ways to measure the metabolic rate of the human body is to take its temperature. The hotter you are, the more metabolic you’ll be. The Latin name for our midsection-solar plexus-means “gathering place for the sun.” This highlights how we’ve long known that the basic design of the human form is a capturing device for the sun’s energy. The more efficiently we harness the sun’s warmth, the better we digest, assimilate, and calorie burn.

It’s no accident that we use temperature metaphors to describe what excites us. An energetic person is called “a fireball,” an attractive person is “hot,” we “warm up” to some people while others leave us “cold.”

As evolutionary fate would have it, body temperature has a rhythm that is consistent and predictable for most everyone, and this daily rhythmic fluctuation reveals some important insight into unleashing our metabolic potential. During the evening and early morning hours when we sleep, body temperature drops. It makes sense that our bodies are cooler at this time because were not busy hunting for animals in the jungle or hunting for bargains at the mall. Our muscles have little work to do at this time; the body is in a state of rest, healing, and repair. We do burn calories as we sleep, but not at the amount we use up in our waking hours.

The moment your eyes open in the morning, body temperature automatically begins to rise.

This is the same thing as saying your metabolism wakes up when you do. It makes biological sense because now the sun is up, and it’s time to find food, find a mate, do battle, and perhaps do a few good deeds. Even if you stayed in bed all day and didn’t move, your temperature/metabolism would still elevate because we’re programmed to entrain with the rhythms of the sun.

Since you’re naturally heating up in the morning, eating at this time is a smart bet if you’re trying to lose weight. Adding food to your gut will increase metabolic rate even more and provide your body with the nutrients its already preparing to process. Think of your gut as a furnace. When you add fuel, the heat rises.

There are, of course, exceptions to every nutritional rule. I’m presenting this information as guidelines – not absolute facts for everyone. Many people who live in hot-weather climates do great with no breakfast, a light breakfast, or a fruit breakfast. You’ll also find that you might do well on a substantial breakfast in the colder months, but will be drawn to eat lighter in the early hours during the warmer seasons. You may also go through periods where the first meal you eat isn’t until after lunch, and that too works fine, until your metabolism shifts into its next phase.

Body temperature continues a slow, steady rise and subsequently peaks around noon. It will exactly reach its apex the very moment the sun finds its high point in the sky – this is a little known scientific fact that shows our profound connection to the cosmos. Our digestive force is therefore hottest at lunchtime. It makes sense, then, that our largest meal would be best consumed at this time, when our ability to pulverize food is strongest.

After our metabolic peak at high noon, body temperature dips for the period between approximately 2:00pm and 5:00pm. It shouldn’t surprise you that just as we feel more awake when body temperature is rising, we feel sleepy when it’s falling. So if you’ve ever felt that there’s something wrong with you because your energy drops somewhere between 2-ish and 5-ish, don’t worry – you’re perfectly normal. Most people you ask will tell you that they feel tired during this time. It’s the human rhythm. Lions love to lounge around and absorb after their big kill. So do you and I.

Body energy – in the form of blood flow and oxygenation is rerouted to digestion after our midday meal.

The result is that we feel even more tired. People in many European and Latin American countries typically have their biggest meal at lunchtime – the peak metabolic time slot of digestion and calorie burning. Then they take a siesta. Businesses shut down, social activity goes quiet, and people snooze. They are honoring and working with the natural rhythms of the body. Entire cultures are designed to function in relation to digestive rhythms.

Except ours.

In America, most of us tank up on caffeine or sugar during the metabolic decline of 2:00 to 5:00 PM, pushing through our fatigue in service to a way of life that values the overdrive gear more than any other speed. Can you imagine what life would be like if you could relax during this time and let go of achieving and conquering? Numerous studies have shown that one or two fifteen- to twenty-minute rest periods during the day will profoundly increase cognitive function, physical performance, mood and energy. You don’t even need to sleep during this time. It’s simply about rest, stillness, closing off outside sensations, and recharging your batteries.

Simply put, resting is a metabolic enhancer.

At around 4:00 to 6:00 PM body temperature starts to rise again. This is when most people feel their energy return. It’s also when the English stop for teatime. It makes perfect sense to do your caffeine at this point, when metabolism is picking up anyway. By around nine o’clock, body temperature begins another downward trend in preparation for sleep. Indeed, sleep research reveals that we cannot fall asleep soundly unless temperature is dropping. Anything, then, that would raise body heat in the late evening would be counterproductive to good sleep. Recall that the act of eating raises body temperature. A big meal before bed could therefore interfere with your slumber. Once again, though, Americans have it backward. We tend to do a small to nonexistent breakfast, a moderate sized lunch, and a more often than not, a big dinner before bed. And this is exactly what you ought to do if your goal is restless sleep and weight gain.

When you eat is as important as what you eat

In a typical study, researchers put a group of people on a 2,000 calorie diet. In the first part of the study, test subjects could only eat their 2,000 calories at breakfast. They ate nothing else for the rest of the day. With this one meal in the morning, everyone either lost weight or maintained their existing weight. In the second phase of the study, the same exact people ate the exact same 2,000 calories diet, except this time, they could only eat it at dinner. With this one meal for the entire day, eaten in the evening, every single person in the study gained weight. Can you see why counting calories to lose weight can be a waste of energy if we don’t take into account when we eat those calories?

Timing is everything. Sumo wrestlers have known for centuries that large meals eaten in the late evening hours will give them the physical advantage they covet most – flab. Simply put, we calorie-burn less efficiently in the late evening hours.

So, if you want to get the ultimate metabolic benefit of eating, don’t eat your most substantial and nutrient-dense meal when your digestion is on a downturn in the late evening hours. Unless you’re seriously considering an unusual career change, I suggest that you relinquish the Sumo diet immediately. Eating little food during the day and much in the evening will never take you where you want to go when it comes to optimizing energy and burning calories.

I would love to hear your experiences with eating and rhythm.
Please let me know your thoughts below – I don’t always get a chance to comment on each one but I do read them.

My warmest regards,
Marc David
Founder of the Institute for the Psychology of Eating
© Institute For The Psychology of Eating, All Rights Reserved, 2014


The Slow Down Diet: Eating for Pleasure, Energy, and Weight Loss

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  • gibson

    In an effort to lose weight after a long post-menopausal stall, I began eating a protein breakfast in the morning instead of waiting until noon. I did lose a few pounds, but my waistline grew smaller and my rings became loose. Daily calories didn’t change, as far as I can tell. My evening meal is usually greek yogurt. Sometimes I add fruit and/or nuts. I’m very comfortable with this routine and don’t usually need a snack between meals.

    • KarnaN


      Thank you for sharing your experience! I am glad that you found a way to nourish yourself that works for you. Being in tune with our bodies is the first step to holistic health. It sounds as though you have made that connection! Being comfortable with our daily routine generally helps motivate us to keep the healthy habits going. Thanks again for your input!


  • cathy ferree

    I’m trying to gain weight but I don’t think it’s healthy to not eat all day. It would play havock with my blood sugar and make my stomach too acidy. Any other suggestions. I know this is not what you were advocating but I’d still appreciate some ideas. I can’t eat a lot, I have to stay away from dairy for the most part and I do stay off of wheat and gluten as best as I can. I have weak digestion overall and get very constipated. I take enzymes, fiber, probiotics and other supplements I have diverticulosis, reflux and IBS. My pcp wants to put me on thyroid but I hate to do that. He thinks it might improve the digestion, anxiety and constipation. I agree that might be true but hate to take a synthetic. He won’t prescribe Armour. Let me know if you have any ideas. I realize this is more than just a comment. LOL! have a great day!

    • KarnaN

      Hi Cathy,

      Karna here at IPE. Thank you so much for sharing your experience! I can’t agree more that it is unhealthy to avoid eating all day. The key piece of this, is eating when your body is naturally hungry. Being in line with our bodies natural cycle, as well as experimenting with diet to find one that supports you could help to resolve many of those unpleasant bodily reactions that you’re dealing with. Here at IPE we also believe there’s an underlying lesson behind your symptoms, and our coaches are trained in helping you explore what that may be for you. In our experience this process may be difficult to do on your own and I would be happy to refer you to one of the counselors in our network if you are interested.
      If you’d like to receive a referral please email us at info@psychologyofeating.com with your age and some details about your main concern and we’ll get back to you.

      Warm regards,


    • Linda dc

      I am also trying to gain weight and have similar symptoms,sounds like you are taking too many supplements. I have cut out processed food,eat a vegan plant diet and have increased my raw food intact. All this has helped me a lot,I also do yoga and walk everyday. It is important that you visit a naturopath for your diet and exercise. When taking supplements you also need to increase your water intake as they can cause constipation. Pawpaw is excellent,you can buy in dried form too.

  • fae

    enjoyed your article. well spoken. thank you. fae

  • http://foodiestudie.blogspot.com Jennifer Brownfield

    Great advice,
    It took me years of being away from my family home (where large dinners were the norm) to allow my body to adjust to the way it likes to eat naturally. I listened to when I was most hungry, and fed my body accordingly. Not surprising, when I was on a good sleep pattern, my body was most hungry in the mornings and lunch, not late in the evening. Now the early hours of the day are my happiest and most productive, I get to enjoy the suns’ rays as well as its energy!

    • Marc David


      Its amazing what can happen when we tune into body wisdom. Recognizing that our body has its own natural rhythm and allowing it to dictate our eating habits helps us to stay energized and in a state of optimal digestion. Keep up the great job of working with your body and listening to its messages!

      Warm regards,

  • Jo Ann Broquie

    This information just makes me want to cry it is so full of truth and so grounded in reason and reverence for the elegance symphony that is the human body. Finally, finally a resource centered on body wisdom. A resource willing to tell the truth about our culture’s lack of understanding for the body and the processes that are inherently designed to bring healing, wholeness and health. There is no monetary value for you personally, Marc, to tell us the truth. No book you are pushing, no latest supplement to ingest. Just honest, beautiful information on how to honor our body. Your genuineness is a breath of vital fresh air against the unfathomable amount of toxic pseudo-information on health and nutrition that exists. IPE is a beacon of light, truth and wisdom for those of us searching to reconnect our soul with our health. Please, please keep up the great work.

    • Marc David

      Hi Jo Ann

      Thank you so much for your kind and beautiful words. It’s so important that we all continue to speak the truth, share the love, and find ways to live and nourish ourselves that are heartfelt and natural. The world needs a lot of healing and wisdom. The good work that we do never ends….

      Warm regards,


  • Joe Grosso


    Your wisdom continues to enlighten me. What you say makes perfect sense. Since we are products of the sun and universe. Your nutritional advice always is logical, true and my own personal experience.
    Thank you and may god bless you.

  • Marc David


    Thank you so much for your comment. I am glad that the article resonated with you!


  • Sheila

    Hello Marc,
    I took your Food Psychology Coaching course, I assumed it would be about nutrition and got so much more than I bargained for. You have opened my eyes to the right way of eating. I am indebted to you! Embracing the feminine principle resonated with me as well as the circadian rhythm of when to eat and who we are as eaters.
    Thank you for gifting us with the Psychology Of Eating. This new way of looking at our relationship with food will change our approach to eating forever.

    • http://www.psychologyofeating.com Marc David

      Sheila, I am so glad that this course has made such an impact on your life. It is amazing the positive effect this information can have on you both personally and professionally when you dive deeper with eating psychology. Thank you for your comment! Warmly, Marc

  • Tara

    Could you site that study?

    What type of weight was lost/gained in each example? Fat or muscle?

    It’s easier to store fat when cortisol levels are high, and cortisol levels tend to be highest in the morning.

    • Lindsay Young

      Hi Tara –

      Lindsay here at IPE.

      You’ll have to go to the original research to have those questions answered for yourself. This post was an excerpt from Marc David’s book, The Slow Down Diet (2005 ed.), which has references for each chapter in the back. You can purchase the book here.

      Below, I have also included a few studies I know Marc references in this chapter on “Eating Rhythm” for you.

      · David Lloyd, Ultradian Rhythms in Life Processes (New York: Springer-Verlag, 1992).

      · B.C. Johnson, “Nutrient Intakes as a Time Signal for Circadian Rhythm,” American Institute of Nutrition, 122, no. 9 (April 28, 1992).

      I’m not sure if fat/muscle-weight loss was distinguished in these studies.

      I hope this helps!



  • http://wherecanibuygarciniacambogia.com Sarah Newman

    Excellent article.

    My grandmother use to say that in order of importance and size breakfast is the king, lunch is the queen and the evening meal is the prince.

    She also said “always leave the dinner table wanting more.” My grandmother lived till she was 96.

    • http://psychologyofeating.com/ Marc David

      Smart, Woman – You’re grandmother!

  • Cynthia

    Hi, I am intrigued with the following scientific fact: “It will exactly reach its apex the very moment the sun finds its high point in the sky – this is a little known scientific fact that shows our profound connection to the cosmos.”

    I have been searching for a citation to no avail. Can you help me?


    • http://psychologyofeating.com/ IPE Staff

      Hi Cynthia,

      This is Lindsay here at the Institute for the Psychology of Eating.
      Great Question! This is from “Chapter Four: The Metabolic Power of Rhythm” in Marc’s book, The Slow Down Diet, and all his references are available in the back of the book by chapter!
      Hope that helps!

      Lindsay | IPE Staff

  • Abbey

    Interesting article. Made a lot of sense to me. I’m wondering what would you suggest would be a good “schedule” for someone who works the night shift (11pm to 7:30 am) part-time? I typically nap a couple hours right before work on my first night back, then stay up until around 3pm, so I can sleep straight (instead of waking up constantly/hourly if I go to bed earlier. Then I get up go to work, only eating before if I have time. Also, my first night back to work,I feel like I’m constantly hungry since I am awake and am constantly snacking that night even though I already had my regular meals and snacks during the day.
    Thank you.

    • https://psychologyofeating.com Marc David

      Hi Abbey,

      Great question. Night shifts are difficult, as I’m sure you know.
      We cannot provide personal health or dietary information without asking about 100 relevant questions. There are many possible directions here. That said, we want to suggest that working with an Eating Psychology Coach may be very helpful for you.

      Have you seen our new Graduate Directory? It is searchable by location as well as by specialty.
      I highly recommend you use this tool to discover someone close by or someone who is willing to work with clients over the phone or skype. There’s always a way to find the health you’re seeking.

      Here’s the link to the directory for your convenience.

      Best wishes to you on your healing journey,

  • Linda dc

    so great to read this article,it confirms my ‘strange’ eating times is actually not strange at all. I eat breakfast at noon(a big one) eat lunch at around 4pm(a huge raw salad) and at 7 or 8 pm I have a cooked meal. But I do need to cut out my 10 pm snack I think,even though I am trying to put on weight.

    • https://psychologyofeating.com Marc David

      Hi Linda,
      Thanks for joining in here.
      As some food for thought, if you ate breakfast earlier, and had lunch around noon, you might not need that 10pm snack, because you have nourished your body through the daylight hours.
      It’s always good to experiment with what works best for you!


  • http://alison@thespecific.com Alison Bremner

    Really good read, thanks for posting this!

    • https://psychologyofeating.com Marc David

      Hi Alison –
      So glad to hear you enjoyed this!


  • Bev

    Hi – I found this article very intriguing to me. I am considered an ‘at risk’ obese person, even though I am physically active and eat healthy meals, I tend to keep on the weight anyway. I’ve had everything tested, believe me, and all my tests are normal. I tend to have a breakfast drink mix in the morning – except a ‘real’ breakfast on weekends (with a meat, a carb, some fruit), then either a protein fiber bar or piece of fruit (such as apple) at around 10 am. At lunch, if I am going for a walk, I just have a protein drink and if not, then a cup of soup. All day I drink water. Usually I am hungry again around 3 ish, so I will have another piece of fruit or some heart-healthy nuts. We usually have a cooked meal at dinner but perhaps I need to switch that to have a cooked meal at lunch and a light protein drink or some yogurt for the evening meal. I’ve struggled with weight issues all of my life. I am going to try to switch those meals and see how it goes!

    • https://psychologyofeating.com Marc David

      Hi Bev,
      Glad to have you here with us and thank you for sharing some of your story – I can imagine this must have been frustrating.

      I’m glad to hear you’re taking some steps to align your eating times with most established and beneficial times to eat, metabolically speaking. I would also highly recommend you consider working with an Eating Psychology Coach.

      Have you seen our new Graduate Directory? It is searchable by location as well as by specialty.
      I highly recommend you use this tool to discover someone close by or someone who is willing to work with clients over the phone or skype.

      Here’s the link to the directory for your convenience.

      My warmest wishes to you on your journey…

  • Ingrid Kuhlman

    Dear Marc,

    Thank you for your article that certainly gave me new insights. I live in Iceland and at this time of year, and until the beginning of May, we have very few hours of daylight. At the darkest we usually have only about four hours of daylight (from 11am until 3pm). This must have a profound effect on our body temperature. During summer however, we have daylight 24 hours a day for 3 months or so. Does this mean that we have to change our eating patterns during winter and summer time?

    • https://psychologyofeating.com Marc David

      Hi Ingrid,
      Wow – Iceland – I’ve always wanted to visit there!
      I would imagine that the extremes in seasonal light that occur in your region would have a tremendous impact on bodily cycles – it’s definitely something to consider and experiment with to see what works best for you and your body, what provides you the most energy, or the most calm.
      I wish I had more insight to offer but I don’t have experience with this. What a truly unique environment you are in! Also, I wonder how traditional Icelanders managed their nutrition in the different seasons. Probably some great clues there…

      Best wishes,

  • Giselle

    Hello Marc! Thank you so much for this article I really loved it & it was just what I needed!
    These last week I’ve been feeling such a mess for eating at irregular times & have noticed that I can’t sleep well when I eat too much at night, so this article has helped me a lot.
    Thank you.
    P.S. Can’t wait for Monday’s conference, it’ll be great!

    • http://psychologyofeating.com/ Marc David

      Hi Giselle,
      I’m glad you connected with the article. Hopefully you have found some insight that will help your sleep patterns. Thank you for reaching out!


  • Amy

    Hi Marc,

    I love this article, it just makes so much sense!

    But I did have a question… I really struggle with what to have for breakfast… all cereals are full of sugar, I don’t really have time to cook anything in the morning, and oats and things like that are full of gluten. Is there anything you could recommend??

    Thank you :)

    Amy x

    • http://www.psychologyofeating.com Marc David

      Hi Amy,

      Try thinking outside of the breakfast box. You can cook up some hardboiled eggs the night before and keep them in the fridge ready for the morning along with some leftover veggies. There are also gluten free hot breakfast alternatives such as buckwheat (which is actually gluten free!). You can make a healthy smoothie, and you can also ask the staff at your local health-food store – they usually have great ideas.

      Thanks for reaching out, and I’m glad you enjoyed the article…


  • http://www.psychologyofeating.com/ Psychology of Eating

    Hi Kristin, thank you so much for your comment! I’m so glad that you found my message useful. I wish you the very best on your journey toward healing! Thanks for being part of our community. Warmly, Marc

  • http://www.psychologyofeating.com/ Psychology of Eating

    Hi Ruth, thanks so much for your question! Intermittent fasting can be really great for some people, but it doesn’t work for others. Try it out if it interests you, and see how your body responds! Warmly, Marc

  • Melanie Lewis Reagan

    I eat my biggest meal always midday. Just recently on two different weekends I ate late and slept terribly!! I was a mess the next day! Not worth it!!

    • http://www.psychologyofeating.com/ Psychology of Eating

      Thanks so much for sharing your experience, Melanie! It’s amazing what a difference the timing of a meal can make, isn’t it?! Warmly, IPE Staff

  • http://www.psychologyofeating.com/ Psychology of Eating

    Hi Wendy, thanks so much for your comment and your pun. :-) With regards to your question about hot flashes, I’m afraid I couldn’t answer it without asking a hundred questions of you! We can’t give medical advice on this blog, but to get some good help and advice, I suggest working with a coach. Feel free to visit our Certified Eating Psychology Coach Directory here: http://tinyurl.com/IPE-directory. Wishing you all the best! Warmly, Marc

  • http://www.psychologyofeating.com/ Psychology of Eating

    Thank you so much for sharing your experiences, Terri! As you learned in the Eating Psychology Coach Certification Training, there is no one diet that will fit for everyone. No two bodies are the same! That isn’t to say that we can’t experiment with different ways of eating, however, so I commend you for trying something different. And by trying it, you figured out it wasn’t for you. So glad you are sleeping again! Thanks for keeping in touch! Warmly, Marc

  • Jimmy DinoSalva Traina

    Can you please provide a reference to this study mentioned in your article. Thanks

    • http://www.psychologyofeating.com/ Psychology of Eating

      Thanks for your question, Jimmy!
      You may find the citation for this study in Marc David’s book, The Slow Down Diet.

      IPE Staff

      • Jimmy DinoSalva Traina

        So I have to buy a book that seems to be based on nothing more than eat slow and be happy, just to see if there is any actual scientific evidence that the time you eat makes any difference in how calories are burned. Yeah I’ll pass on that.

        • http://www.psychologyofeating.com/ Psychology of Eating

          No need to buy the book, Jimmy. You may find numerous peer reviewed studies by simply Googling ‘circadian rhythms’ or ‘metabolism’.
          IPE Staff

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.