Is Breakfast Really the Most Important Meal of The Day?

June 28, 2012 in Categories: by

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The paleo community is accustomed to pushing back against dietary recommendations from the USDA and medical establishment.  We like to argue that whole grains and legumes are universally detrimental to human health, that the high omega-6 fatty acid content of modern vegetable oils and grain-fed meat is responsible for the rise in cardiovascular disease seen in the last three decades, and that eating refined sugars causes decreased insulin and leptin sensitivity and is responsible for the current diabetes epidemic.  These arguments are all extremely well backed-up with solid science, which is one of the reasons why the paleo diet is so successful.  The paleo diet is the first diet to be based on comprehensive, current, high-quality scientific evidence of the effect of specific foods on our overall health (and structured with an ancestral health perspective).  And while aspects of this diet will almost certainly change as more research is performed, the foundation is rock solid.

When it comes to whether or not breakfast is important, the paleo community is firmly divided.  Many supporters of intermittent fasting prefer to skip breakfast at least a couple of times per week (Chris Kresser has stated that he skips breakfast 2-3 times per week), while other paleo gurus almost never eat breakfast at all (Mark Sisson has stated that he almost never eats breakfast, Mat Lalonde doesn’t eat until lunch and sometimes only eats one meal per day).  The rationale behind skipping breakfast comes from two places:  listening to our bodies and not eating until we’re hungry and the benefits of intermittent fasting.  Many in the paleo community will tell you that breakfast is “just another meal” and there is nothing special about it.  Many will tell you that if you aren’t hungry in the morning, you shouldn’t eat.  I believe this to be true for people who are already extremely healthy, but if you have a history of metabolic derangement (i.e., if you were ever very overweight) or a history of adrenal fatigue, then skipping breakfast might not be such a good idea.

Cortisol management is a key goal of a paleolithic lifestyle and is essential for regulating inflammation, boosting the immune system, and regulating energy and mood.  Cortisol is an essential hormone, involved not only in the body’s normal stress response, but also in regulating blood sugar and circadian rhythms.  Cortisol is naturally at its highest in the morning.  If you are getting adequate sleep and managing your stress, your cortisol level gradually decreases throughout the day and the first three quarters of your night’s sleep.  There are two ways your cortisol can be disregulated.  The first is chronically elevated cortisol, where your cortisol still decreases throughout the day but remains higher than normal at all times.  The second is where your cortisol starts off low in the morning and increases through the day, which is the source of that second wind in the evening for many who are chronically sleep-deprived (this is called the “tired and wired”: pattern).  If you have a history of adrenal fatigue, inadequate sleep or poor sleep quality, metabolic syndrome or obesity, or poor stress management, then you may not have normal cortisol levels (you might have chronically elevated cortisol or tired and wired cortisol expression).  And even if you have made progress toward addressing these issues, your cortisol management may be tenuous.  This is what happened to me.

The issue with skipping breakfast is that your body increases cortisol in order to stimulate glycolysis or gluconeogenesis to raise your blood sugar so that your body has energy for whatever you are doing.  If you have a morning coffee, your cortisol will increase even more.  In a very healthy individual with perfectly normal cortisol levels and well-regulated expression of hunger hormones, good insulin-sensitivity and good leptin-sensitivity, this rise is temporary and the body adapts beautifully.  But if you don’t have normal cortisol levels or optimal insulin sensitivity or optimal leptin sensitivity or well-regulated ghrelin, this rise in cortisol in the morning can lead to increased cortisol throughout the day or abnormal swings in cortisol levels.  Importantly, there is evidence that women are more susceptible to an exaggerated cortisol response to fasting.  Women, therefore, are less likely to see a benefit to routinely skipping breakfast.  When I started skipping breakfast on a regular basis, I noticed that my weight started creeping up and that my sleep quality deteriorated, classic signs of high cortisol (of course it took me two months to figure this out!).  When I started eating breakfast again, I found that my hunger was less throughout the day, I lost the weight that I had gained quite quickly, and I started sleeping much better.

If your goal is weight loss, then skipping breakfast routinely is probably not the best choice (it’s probably fine and maybe even beneficial if you are already quite lean and very healthy).  In fact, eating breakfast every day is one of the three habits known to correlate very strongly with not only weight loss success but also in maintaining that weight loss once your goal weight is reached.  Of course, this doesn’t mean that you can’t experiment with Intermittent Fasting.  And it doesn’t mean that skipping breakfast on a regular basis won’t work well for you in the future.  Just be mindful of how it’s affecting you so that you can gauge whether or not breakfast really is the most important meal of the day for you.


Hi Sarah, I spent a good part of the day yesterday reading your blog. What interesting information! I have NEVER heard any information on the diet you recommend for auto-immune disease protocol. I have Hashimoto’s. Could you point me to more info about the things you say are a no-no for someone dealing with inflammatory issues…..I am so dismayed to read the list for things I should def. avoid. Some of my favs!!! I have done pretty well with low-carb, but to find out these are things I should be avoiding is a blow! =) How do I know if they are causing me distress (obviously by leaving them out of my diet, I may find out?)? I would appreciate any info you can direct me toward….I’ve had thyroid disease for four years now and have NEVER heard this….why is our medical community so satisfied with slapping a pill at us and then not adding any real nutritional info?????? Anyway, is there something else I can read about why these things are not good for someone with inflammatory issues?? Thanks so much for ALL your information…you are very inspiring!

Hi Suzanne,

My summary of the Autoimmune Protocol reflects the recommendations from Robb Wolf (The Paleo Solution), Lorain Cordain (The Paleo Answer), Mat Lalonde (various talks and interviews), Chris Kresser (various talks and interviews), and Terry Wahls (her TedEx talk, interviews, website and she will have a book in early 2014). I have links to the books and websites in I am starting to go through each food systematically and explain the WHYs (look under living paleo menu-autoimmune disease). Hashimotos is one of the classic autoimmune conditions that people generally see huge improvement for with this protocol. You can start playing with adding food back in once your thyroid function returns to normal (and you’ll want to get tested more frequently so you can adjust your meds while you do this!). Several paleo bloggers actually have dealt with Hashimotos. If you google Hashimotos and Paleo, you’ll probably get a bunch of podcast interviews and blog posts related to people’s success stories. I hope this helps!

Good take on the subject! I was also following closely the debate about intermittent fasting, as I have found it useful for weight loss with a creeping suspicion that it is coming at the price of other health factors. I think I may just need to take a few steps back and focus on eating when hunger naturally ensues. If you have a disordered history with food, this is much harder than it sounds!

I appreciate your take on this. I’ve been stressed for a long time. I tried IF starting last year, after being lc-paleo for a year and found that it made my cortisol would swing both ways depending on what was going on in my life. Prior to these conversations I thought it was something else (not the IF) because I wasn’t hungry, but I wasn’t losing weight or getting any other benefit from it (quite the opposite actually). I felt like my mind was going a million miles a minute, and that was even after weaning myself off coffee. I am now taking amino acids to control things. I wasn’t heavy all my life, but I have endometriosis and gluten allergies. I think that if you have any health issues, that you need to be very kind and gentle to your body, rather than beat it into submission. It’s nice to know that I’m not the only one that had this problem.

Thanks, so much, Sarah for all the info!! I can see I am going to be doing research for quite some time!!! YOu’ve given me a lot to work with, and I look forward to following your blog. Again, thanks so much for bringing to light so many issues that we all struggle with!

So, what do you know about anxiety issues? Anything? I’m resonating with the whole Cortisol being high in the morning and low in the afternoon…I have been dealing with physiological anxiety (as in, there isn’t a whole lot in my environment that has changed to stress me this much – I think my coritsol/adrenaline is out of wack). It’s been this way since the birth of my daughter 2 1/2 years ago – I think that put enough stress on me that it caused something to go out of balance and it hasn’t gone back. Specifically, I expereince poor sleep quality in the later half of the night, early in the morning and usually get to feeling “normal” late in the afternoon – this matches with your description of cortisol fluctuation. So, what do I do to manage cortisol and heal this system?? Can you point me to any resources for further study?? I will be looking as well – this was a GREAT article! Thank you!

Hi Amanda,

It definitely sounds like your cortisol is out of whack. I think you might find this post interesting:

I also used to get panic attacks when my blood sugar dropped too low between meals. Eating protein and veggies and being mindful of high sugar foods helps with this. Also, turning off inflammation in the brain can be challenging. One thing that can be very helpful (on top of a paleo diet with a focus on gut healing) is just having fun and doing something mentally stimulating every day (like a crossword or sudoku). Chris Kresser has some great resources for gut-brain axis issues including supplement recommendations to help.

Thank you thank you thank you from another Amanda! I think this was the missing link I needed to know about as well that hadn’t dawned on me until you mentioned it too. I know my Cortisol and stress management was out of whack before I started this journey to health, but things seemed to really improve so much once I figured out the Paleo/AIP/FODMaps mixture diet that worked for my body and started to heal my gut. Yet, no matter what diet/supplements I’ve tried as I’m healing, losing weight has been much slower than I should be, I’m still having the same problem you are late at night/early morning and not feeling normal until late in the afternoon as long as I’ve eaten the right lunch. I keep reading the key is sleep, but everything I’ve tried to get myself to that “great night sleep” hasn’t worked, the sudoku etc works great to get me to relax to fall asleep at night, but it hasn’t helped with the late night/early morning “racing” issue. I’ve had relatives tell me it’s probably your hormones changing, I’m 39, plus insomnia runs in the family so not much you can do about it. Now I have something specific to work on again, I feel like there’s hope for a good night sleep yet! Thank you Sarah as well, I’ll be checking out the other post as well for more ideas!

Thank you for posting this! This came in a very timely manner. I am not loosing or gaining weight (I am very overweight and BFing so I need to loose weight but need to nourish him and my self at the same time) and was wondering about intermittent fasting but you made some good points. Ill deal for a while longer until I can figure out why I am stuck at such a high weight maintenance point and reach a healthy normal with my body first.

As you lose weight, your body will periodically stall/plateau at a weight while your hormones adjust. I always found that focusing on more sleep was the best thing I could do to get through those plateaus. Also, I found it very hard to lose weight quickly while the first year of breastfeeding (a bit easier after that when the frequency decreased and I didn’t need to make so much milk). Try to be patient with your body. Once your boy is eating solids and your sleeping better, it should all come together (especially if you’ve been sticking to paleo while you wait and resolving inflammation and getting hormones back to normal). Good luck!

You’re right. That should have read USDA (edited now). Pardon my canadianess (both the jobs of the FDA and of the USDA fall under one government department in Canada, called Health Canada, so I do erroneously mix them up from time to time and I apologize).

Hi Paleo Mom,

You are so inspiring and I could read your posts all day, thank you! I found this post very interesting because I am going back and forth on the right food timing and patterns for my current state of health. I have moderate adrenal fatigue and chronic fatigue syndrome. Most things I read in order to help heal adrenals and manage cortisol is eating every 2-3 hours and ensuring you are eating whole grain carbs. I have been on and off following the autoimmune protocol and I can just feel that it is what my body needs, but I’m afraid that I am not fully healing my adrenals or cfs because the only carbs I eat are sweet potatoes, starchy veggies, and occasional fruit (in the afternoon). What are you thoughts on diet/timing of eating for adrenals and cfs?

Well, I definitely don’t think that whole grains is a good choice for CFS! I do think that eating more frequently can be helpful for adrenal fatigue plus not going really low carb (sounds like you’re probably getting a good amount between starchy veggies and some fruit), but the biggest difference for adrenal fatigue will actually come for getting tons of sleep and managing stress. My general rule of thumb is to stick with what’s working. If AIP but eating more frequently is working, then that’s a good choice.

Oh my gawrsh, thank you. THIS is the post I needed to get me off the coffee-until-noon habit that I hoped/wished was helping me with metabolism and food issues.

My first day I wasn’t quite on the mark, having coffee BEFORE breakfast, but I’ll flip it around tomorrow. 🙂

I drink bulletproof coffee in the am and then eat around 11. Bulletproof coffee as you know has lots of good fats and calories. that considered “breakfast” or IF?

OMG – I know this is an older post, but I surfed into it yesterday. The part about coffee and cortisol… is that related to caffeine consumption? Or the coffee itself??? I ask because I am eating pretty cleanly these days, and the first week or so I was losing weight pretty well – but I had stopped coffee (to get off caffeine). Now I’m on decaf and the weight loss is crawling. I am sure I have cortisol issues, and wondering if the coffee is a trigger!

I love LOVE your blog. Q- I am very overweight, I am currently doing paleo…making the switch to AIP. I have tried everything to lose weight, I even did a juice fast for 123 days…no food! And even then I detested breakfast. I seriously could not eat before noon (I woke around 6am) in the middle of starving myself! Do I need to force feed myself?

Some people do well with breakfast, some people don’t. You will have to play around with when and what you eat to find what works best for you. – Christina, Sarah’s assistant

Breakfast is my body’s most important meal. In fact, I find myself hungry all morning, even after eating a healthy veggie and egg breakfast. It’s like my body processes food much faster in the mornings. If I had to skip a meal, supper in the evening would be much easier for me. I don’t mind going to bed hungry. I have about 20 pounds to lose, as I have gained since the death of my father 7 months ago. I assume the grief/stress increased my cortisol or threw it out of whack. I have had trouble doing any kind of diet or food restrictions since that time. Do you have any articles on either issue – all morning appetite or grief’s affect on diet?

[…] Even if we DO eat breakfast, but fail to eat enough, our blood sugar continues to dip lower and lower and our brains go into survival mode. Our bodies start getting anxious about when our next meal will come, which triggers cravings, not to mention renders us mentally and physically useless. And we stay on this rollercoaster for the rest of the day. (The Paleo Mom has some great science to back me up here.) […]

I just finished reading the Adrenal Reset Diet by Dr. Christianson. I am curious, Have you read this book, and what are your thoughts on the issue of carb cycling. I am currently dealing with several chronic health issues that have been in my life for 10+ years. Idiopathic Autoimmune (Labeled such because they have not confirmed Lupus, and they aren’t sure why my lab values are what they are) Fibromyalgia, and CFS. I have also learned that I have all the symptoms of Adrenal Fatigue as well. (Doctors I have seen do not recognize Adrenal Fatigue as a true health concern.) I have been on the Adrenal Reset Diet for about a week so far and I am feeling results. Those results being increased energy to do things such as working in my garden which I am not always able to do. My main questions are: How similar is this diet with your AIP diet, and do you see any concerns with the ARD?
Thank you for your time.

“In fact, eating breakfast every day is one of the three habits known to correlate very strongly with not only weight loss success but also in maintaining that weight loss once your goal weight is reached. ”

Could you tell me what the other two habits are?

I realize this is an older post, but here is my issue…. I am pushing 40, work from home at a desk job. I have had a hysterectomy, so hormones are probably not 100% on par, but I do still have ovaries that are functioning. I have been mostly paleo for about 2 years, and I definitely see a difference. I have lost nearly 20 pounds, but nothing recently. I tend to waffle between 139-146, and that can fluctuate literally from day to day. I probably don’t get enough sleep, but not for lack of trying. I have always been a bit of an insomniac, waking up in the wee hours and having trouble falling back to sleep. I go to bed between 9-10 most nights. Some nights I sleep clear through, but not usually. I do coffee with honey and coconut or almond milk in the morning, and I take Synthroid, so I can’t eat first thing anyway. I’m really not hungry until at least 10:00 or later, at which point I either heat something up, have a salad, or have a vegetable protein shake with greens and berries. This is all I eat until supper time. If I eat earlier, I am starving all day. I could stand to lose 10 pounds, but I’m not stressing over it. I started lifting weights again, so I may have to sacrifice weight loss for muscle mass. Lifting helps with my sciatica tremendously, so I can’t do without it. I also walk about 2-3 miles most days, plus whatever running around the house or errands adds to that. Thoughts on whether this is good, bad, or maybe indicates a hormone issue?

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