Questioning “The most important meal of the day”
Claire - Sunday, March 24, 2013
This one is quite science heavy, but it will be part of our up coming Leptin For Laymen video series and will be simplified in that. So don't get too concerned if this seems a little complicated.
Last weekend I took part in an amazing obstacle race called Kokoda Grunt and in the true spirit of the Kokoda Challenge foundation they made it really tough. It was 13km long with over 850m of elevation, which is the equivalent of climbing 286 flights of stairs. Plus lots of walls, monkey bars, mud crawls and various other obstacles. In the above 30C temperatures, it took us about 4 hours to get our whole team through. So, what did I have for breakfast pre-race to get through such a full on event?
1L coconut water
1 coffee with butter, coconut oil and a dash of double cream
You might ask, where is the actual food? Where are the carbohydrates? Now there is much more to the story than the little bit I am going to share with you today, but hopefully it will get you asking a few questions about the modern wisdom of labeling breakfast as the most important meal of the day.
Let’s start with a quote out of "Good Health in the 21st Century" by Dr Carole Hungerford, which incidentally is a highly informative read. If you don't own a copy, seriously think about it next time you are book shopping.
"The biochemistry of breakfast
Insulin resistance is the end result of continuously high levels of circulating insulin. In the West, we rarely fast. Breakfast is meant to be the breaking of a fast. During that fast, our insulin levels should have fallen, stayed low until all the food is absorbed from the stomach, has entered and left the circulation, and has been distributed to the cells of the liver, fat and muscles. During this time, the cells of those organs have minimal exposure to insulin and thus maintain insulin sensitivity.
Suppose two individuals eat the same high-calorie diet. One is a grazer and spreads the meal across the waking hours of the day; the other eats in two sittings, with a long gap between the last meal of the day and the first meal of the following day. The first individual develops insulin resistance and a fatty liver, but the second stands a good chance of avoiding these complications. Why?
Throughout human evolution, hormonal influences developed to tie in with various circadian and diurnal cycles. Hormonal patterns and the impact of various activities can now be studied by laboratory measurement. One of the hormones of interest is DHEA or dehydroepiandrosterone.
DHEA is made of cholesterol, and it is a precursor to all the eostrogens and testosterones we produce. Taken as a medication, it is a banned drug for Olympic athletes because it increases their performance and is deemed to give them an unfair advantage. It is also known as a longevity hormone. Pathological states aside, DHEA levels are an indicator of the health of the individual. According to Ray Kearny, an immunologist from the University of Sydney (and a member of the delayed-breakfast brigade), contracting our eating hours by having a late start to the day improves DHEA output and appears to reduce cancer risk.
We produce DHEA in opposition to growth hormone and the glucocorticoids. High levels are reached in the early hours of the morning, as these other hormone levels fall. The rise in DHEA production is stimulated by bright sunlight, so it makes sense to be out of doors then. With our first meal, further glucocorticosteroids are produced and the DHEA surge is suppressed. The longer breakfast is delayed, the longer the DHEA peak lasts and the greater the overall output.
Early morning urine has a high concentration of DHEA. It is probably for this reason that some monks drink a glass of their own urine first thing in the morning. (Should we suggest this to the Olympians?)
The health benefits of the overnight fast include both the restoration of insulin sensitivity and the optimisation of DHEA production. Less quirky than consuming odd drinks and easier than undergoing long fasts is simply delaying breakfast until hunger asserts itself. Take a morning jog to complete the picture.
Further support for 'no breakfast' came from a report in The Lancet that normal children were unaffected or performed better without breakfast.
This all happened as a matter of course for our primitive ancestors. They ate at dusk, and finishing the meal around the campfire. Without artificial lighting they were finished with food relatively early in the evening. Although they arose with the sun, there is good reason to believe that some time elapsed before they ate. Stored food would be eaten by small animals, or would attract large animals to which humans were also prey. Almost all food was fresh (with all the attendant health benefits), whole and acquired through work. They had to find, even hunt, kill and cook breakfast before they could eat. Maybe they snacked on a few nuts and berries as they went. You worked first you ate second. You burnt energy, and then you replaced it. We do the reverse. We eat first, pre-emptively refueling in case our supplies run low. The price is called metabolic syndrome.
So in short, we really aren't giving our body enough "down-time" from insulin or enough time with peak DHEA. DHEA, as mentioned above, is the building block for all our sex hormones thus playing a huge role in fertility, but it is much more than that. DHEA helps keep our cells "young", it plays a part in cognition, muscle strength, your immune system, sex drive, cardiovascular health … the list goes on."
The commonly accepted theory behind the hearty breakfast is it sets you up with your energy needs for the day (which begs the question, ‘what was the purpose of last night’s meal, then?’) and stops your body going into "starvation mode". This is where the body supposedly begins to consume its own protein (muscle tissue) to fuel itself and slows down metabolic rate to conserve energy.
A study by Stote et al. titled A controlled trial of reduced meal frequency without caloric restriction in healthy, normal weight, middle-aged males had a control group eating the same caloric amount in three spaced-out meals in a day and compared these subjects to a group eating the same number of calories in only one meal. Neither group participated in any exercise over the 8-week trial. The one meal a day group lost body fat, gained lean muscle and lowered their cortisol levels.
Consuming just one meal a day is arguably a little excessive in terms of fasting, but it is interesting to note how the body changes simply by giving the body insulin some down time.
So, why not skip dinner if you are going to skip a meal? Why would you choose to go to bed with food in your stomach instead of waiting until morning?
First off is the fact that DHEA is stimulated by sunlight. Your body needs those 8-10 hours of darkness to move through the digestion and insulin phase to then start producing DHEA as the sun begins to come up. At this point, there is a spike in cortisol, this is the time most people eat their breakfast as they often feel "ravenous", but interestingly enough that passes quite quickly, especially if you move out into the sun at this time: A morning walk, perhaps. This spike is nothing unnatural. It is like nature’s alarm clock saying, “Hey! Get up, because you need to think about finding and preparing some food.” Your body expects it will be a few hours before you will have food in front of you.
There is another set of hormones at play here. One of the hormones that controls appetite is called leptin. It helps maintain the feeling of satiation after eating. Leptin levels are markedly increased when the body is exposed to both insulin and melatonin. Melatonin is one of the hormones involved in sleep. When the body has a normal sensitivity to leptin, adults tend to sleep through the night without waking up hungry. These higher levels of leptin last until about 15 hours after your last meal.