There is substantial evidence that elevated levels of cortisol on a regular basis is not good for overall well being (Sapolsky; Talbot). Additionally, chronic stress and subsequent elevated cortisol levels can increase a person’s appetite for “comfort” foods, which can lead to excess calorie intake (Adam & Epel). These extra calories, due to the effects of cortisol, will likely be stored in the midsection, also known as visceral fat, the really bad stuff (Adam & Epel; Talbot). However, the deposition of visceral fat will ONLY happen if you ingest EXTRA calories! If you have elevated cortisol BUT ingest less calories than your body will use then you will actually LOSE weight, including visceral fat! With all that said, there has been recommendations that eating more often, say 5 or 6 times a day, will help to decrease cortisol levels. Is this true? The quick answer is NO!
I recently came across the “eat often to lower cortisol levels” thing in a couple of places. First, we have to thank our Tone It Up girls (see HERE and HERE for more about their other recommendations, I mean bullshit) for the following information, I mean MISinformation. They state;
“If you don’t eat often, cortisol levels increase…causing you to have more belly fat!…You will be eating five meals a day. No skipping meals!…Meal two and four are more like energy snacks. They are ‘in-between’ meals, but are the most important to include to promote healthy hormones…Cortisol directly stores visceral fat in your abdomen covering those beautiful muscles you work so hard for.” (p.7)
As usual the Tone It Up girls have no evidence to support their statements (at least they are consistent). I will get into the cortisol aspects in a minute but first I want to point out another one of their stupid statements. Included in the above quotes was this;
“Cortisol directly stores visceral fat in your abdomen covering those beautiful muscles…” (emphasis added).
Visceral fat is located around the organs and underneath the abdominal muscles. This means that this type of fat does NOT cover the muscles. The type of fat that covers the muscles is subcutane0us fat, NOT visceral fat. We can add this to their pile of bullshit!
Next, the following quote is from the book The Cortisol Connection by Shawn Talbot Ph.D., FACSM;
“You’ll notice that each snack ‘lasts’ for two hours, until it is time for a meal that ‘lasts’ for three hours…In this scenario, your snacks act as ‘bridges between meals and as significant controllers of cortisol, blood sugar, and overall metabolic rate. Do not neglect them!” (p.268) and “Remember that we need to space our meals and snack throughout the day to help regulate cortisol metabolism” (p.269).
Dr. Talbot does give references for a lot of the information he gives about cortisol but, interestingly he gives no references for these statements. As you will see below, the likely reason for a lack of references is the fact that there is no evidence to support the higher meal frequency being beneficial.
So we have the Tone It Up girls (clearly NOT the shinning stars of evidence-based recommendations) and Dr. Talbot, who actually has some impressive credentials, recommending at least 5 meals to improve cortisol levels. The problem is that there is NO evidence that eating 5 meals a day, compared to 3 meals a day will improve cortisol levels. Seeing that I am calling Bullshit on this recommendation I better back up my view with some evidence.
The first thing I want to point out is the fact that the majority of evidence finds that the act of eating increases cortisol levels (Benedict et al; Gonzalez-Bono et al; Lemmons et al; ). The response is most pronounced at the noontime feeding (Benedict et al). The reason for the cortisol response is likely due to the fact that eating is a physiological stressor. One of the papers looking at meal-induced cortisol release stated “…food intake in general represents a fundamental immune challenge to the organism, we supposed that the meal-induced cortisol release could serve an immunological function” (Benedict et al, p.1692). A bit more technical view of this subject, by Power and Schulkin, “Organisms must consume food in order to survive, but the act of consumption brings exogenous substances into the body and presents a challenge to the stability of the internal milieu” (chapter 10, paragraph 10).
With the above in mind, how does “increasing meal frequency to lower cortisol levels” make physiological sense? It doesn’t make sense to me. Additionally, after reading a number of papers and books related to this topic I have yet to find any evidence that shows a higher eating frequency, typically stated as 5 to 6 meals a day, will have a reduced affect on overall cortisol levels compared to a lower eating frequency, typically 3 meals a day. There is just no evidence for this view.
Finally, there is one more related aspect that I think is pertinent to this subject, which is intermittent fasting (IF). IF regimens usually utilized a meal pattern that results in NOT eating for 15 to 24 hours every other day. This eating pattern has demonstrated many health benefits in both animals and humans (Johnson et al; Vardy et al). Johnson et al states;
“Based on a broad range of calorie restriction studies in animals in which virtually all diseases are delayed, prevented or ameliorated by calorie restriction, we propose that this dietary pattern [intermittent fasting], with or without weight loss, will delay, prevent or improve a wide variety of human diseases in addition to the above, including multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, atherosclerosis, NIDDM, congestive heart failure, and resistance to brain injury from thrombotic stroke.” (p.211)
From this evidence, even if there were an increase in cortisol from less frequent eating, there seems to be an overall benefit from periods of less frequent eating so there should be little concern with having to eat frequently.
In conclusion, there is no evidence that a frequent eating pattern will improve overall cortisol levels relative to less frequent eating patterns. Therefore, for those trying to lose weight and/or trying to be healthy there is no need to worry about eating often (also see the post about meal frequency and metabolic rate). In fact, the concern about eating often is probably more likely to be considered stressful by many people which is likely to elicit more cortisol. The bottom-line, find a meal frequency that works with your life and makes you feel well.
References
Adam, T. & Epel, E. (2007). Stress, eating and the reward system. Physiology & Behavior; 91
Benedict, C. et al (2005). Gut protein uptake and mechanisms of meal-induced cortisol release. J Clin Endocrinology Metab; 90
Johnson, J. et al (2006). The effect on health of alternate day calorie restriction: Eating less and more than needed on alternate days prolongs life. Med Hypothesis; 67
Gonzalez-Bono, E. et al (2002). Glucose but not protein or fat load amplifies the cortisol response to psychological stress. Hormones & Behavior; 41
Lemmens, S. et al (2011). Influence of consumption of a high-protein vs high-carbohydrate meal on the physiological cortisol and psychological mood response in men and women. PLoS ONE; 6(2)
Powers, M. & Schulkin, J. (2009). The evolution of obesity [kindle]. John Hopkins University Press. Baltimore, Maryland.
Sapolsky, R. (2004). Why Zebras Don’t Get Ulcers. Holt Paperbacks.
Talbot, S. (2007). The Cortisol Connection. Retrieved from http://janne.pool.fi/books/The%20Cortisol%20Connection%20Why%20Stress%20Makes%20You%20Fat%20and%20Ruins%20Your%20Health%20-%20And%20What%20You%20Can%20Do%20About%20It,%202nd%20Edition.pdf
Vardy, K. & Hellerstein, M. (2007). Alternate-day fasting and chronic disease prevention: a review of human and animal studies. Am J Clin Nutr; 86