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?
2L water
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.
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