I think much of this obesity and diabetic epidemic might be eliminated if certain dietary guidelines were made clear. So I picked out my favorite "claims" from the magazine and now am going to unpack why I think they aren't necessarily true and back it up with scientific studies. There were a lot of points in the magazine to pick out, so I decided instead of conquering them all in one post, I will do it in a series (it also takes a lot of work to unpack these claims, you know!!). Anyways, let's get started. I hope some of this clarifies and enlightens you into realizing that not everything we read or watch is truth (and we must think for ourselves and determine what works for us in turn).
"Breakfast is especially important if you need to control your weight. It helps jump start your metabolism and makes you less likely to overeat later."
The whole notion of three square meals a day is a modern American invention. Since our society is on a constant time schedule, meal planning had to follow. Because of this meal structure we began to eat according to time instead of our body's natural satiety rhythms. Regardless, because of the omnipresence of food, I think we should only eat when our bodies are hungry. Many countries like Italy, for example, skip breakfast entirely and eat their biggest meal in the late afternoon and a small dinner late at night. It's worth noting that Mediterranean countries have lower rates of obesity which could be due to the content of their food, or it could be due to their meal structures.
When we break up the word breakfast, we realize its meaning: we are "breaking a fast" our bodies have endured over night. But, morning might not be the ideal time to end this fast. When we wake up, our bodies are still detoxing from the night before, clearing endotoxins and digestive waste. If we fast through the morning and decide not to eat, digestion is fully completed, and primal survival mechanisms are triggered, maximizing the body's capacity to generate energy and alertness--just what we need in the morning when heading off to school or work. This process is called SNS (the sympathetic nervous system). Right before our bodies wake us up SNS is turned on, priming the body for action. SNS puts the body in "fight or flight" mode, a reason why cortisol is highest in humans in the morning. Cortisol, as we know, is a stress hormone released in "fight or flight" situations. A little bit in the body isn't unnatural and is actually healthy. The release of cortisol gives us energy in this sense because it is priming us for action to "go get food" since it is absent. During these morning hours without food, the body is utilizing glycogen stores (where we store carbs when we eat) that were filled the night before. That means that with SNS turned on, our bodies will use the energy (and fat) already in our bodies instead of getting excess energy from an external source.*
So eating something in the morning (like that box of cornflakes...), shuts the SNS system down and there goes the energy producing system as well. Instead, an opposite mechanism known as PSNS (Para sympathetic nervous system) is turned on, making us sleepy and slow. It turns off fat-burning mechanisms too because a box of "healthy whole-grain" cereal overflows glycogen stores. This leaves us starting the day in a state of energy density and saturation. When we are feeding ourselves massive loads of carbs, the reaction is even worse, because it spikes our insulin momentarily, but will make us starving for more food in the next couple of hours and leave us feeling sluggish.
Most Hunter-gatherer's were known for only eating one meal in the evening (since they spent the whole day collecting and hunting for their food). They were fasting throughout the whole day keeping their daily SNS going and leaving PSNS to only activate at night (promoting digestion and sleepiness-- just what we need before bed!).*
By eating in the morning, we severely interrupt our body's circadian clock and we haven't adapted to these interruptions. If we fasted throughout the day, SNS would stay on, promoting alertness and action. Then, when we ate our meal at night PSNS would regulate digestion and sleep for night. Since we have imbalanced this, it causes sleepiness throughout the day, as I stated, but can also affect our nighttime sleep.*
A number of research studies suggest that intermittent fasting, or skipping our morning meal, and eating later in the day, is actually extremely beneficial for health and longevity. We have to figure out what amount of time works for going without food but most people go from their last meal the night before let's say at 6 pm and wait anywhere from 15-18 hours the next day (so they are breaking their fast at 9am-12pm). If we continue this daily, it constricts our eating window into anywhere from 6-8 hours.
Fasting also induces a process called autophagy ("self-eating"). I couldn't have summarized it better than this article does: "During autophagy, organelles called lysosomes break down waste products inside the cells. Lysosomes break down other worn-out organelles, digest food particles, and destroy viruses and bacteria (using hydrolase enzymes). You could think of them as the stomach of the cell, and/or part of the cellular immune system...Without autophagy, damaged organelles survive, and cells become less efficient."**
Short-term fasting can induce autophagy. This is why fasting is so important. By setting off autophagy, it allows the body to recycle damaged components, and eat away at invading microbes. For these reasons, autophagy may protect against neurodegeneration, viral and bacterial infections, and cancer by getting rid/repairing the "old" cells in place for new, healthier ones.
The Diabetes magazine stated that eating breakfast helps jump start our metabolisms. We know that this is false because it is antagonistic to the effects of SNS and instead turns on PSNS (shutting off "fight or flight" mode). Many people worry that by not eating they may die in a few hours or their bodies will go in to starvation mode. (Actually it takes around 60 hours to pass before the metabolism is shown as slowing down from not having food.*) Interestingly, studies on short-term fasting have shown metabolic rate increase anywhere from 3.6-10% which makes sense because the body turns on our adrenaline to go and "search for food" (give us energy). Hunter-gatherer's definitely came across periods of time when they didn't have much food or had to hunt extra long one day to find something. The statement that our bodies will be negatively impacted by not eating for 16 hours is absurd. If our metabolisms shut down after a few hours and made us not want to move to go and get food, we would lay down and die. HG's were going for points of 36 hours or more without food. They depended on fast metabolisms to keep them energized in their hunts. If our bodies didn't learn how to adapt to short spans without food, we obviously still wouldn't be here. So short-term fasting will not slow down the metabolism!
In a study of mice fed either ad libitum (control group, eat when they want and as much as they want), calorically restricted (scientists limit their food intake), or IF (intermittent fasting, but kept the same amount of calories as the ad libitum group), the IF and calorically restricted group both saw their concentrations of glucose and insulin decrease significantly.* This in turn means that insulin sensitivity improved, a positive result. Diabetics are insulin resistant: this means that cells in their body cannot respond to insulin. When they eat a carbohydrate, which breaks down into sugar, their bodies cannot utilize the glucose so release more insulin (to stabilize blood glucose). Too much insulin secretion makes it harder for the body to use stored fat for energy so diabetics are sugar-burners. They depend on the carbs they eat to keep their energy levels going keeping the fat on their bodies too. Insulin sensitivity is the exact opposite. It is having an acute response to the carbs consumed, so when less insulin is secreted, blood glucose doesn't spike as much and stored fat can be utilized as energy easily.
Another interesting point of this study was that while the calorie restricted group was consuming much less food, the IF group was eating similar amounts of calories to the ad libitum group. This means that we don't have to achieve improved insulin sensitivity by restricting the amount of food we eat. Instead, we can fast and keep our calories constant and still see positive results! (Intermittent fasting isn't about caloric restriction, but eating within a constrained window).
In another study in young overweight women, intermittent fasting was observed as just as "effective as caloric restriction in regard to weight loss, insulin sensitivity, and reducing disease risk."
I could list a bunch of studies that show the benefits of fasting, but I will just explain one more. This study took both men and women of similar age and weight and implemented an fasting regimen for just 8 weeks. By the end of the trial they saw improvements in several parameters of body composition, such as a decreased waist circumference, and lower body weight overall. The study mainly showed that fasting can help prevent coronary heart disease, by positively effecting risk factors for CHD. When subjects' blood lipid profiles were taken at the end of the study, LDL (bad cholesterol) and triglycerides had both reduced, while HDL (good cholesterol) stayed the same. Similarly, while fat mass was reduced in the subjects, fat-free mass (muscle) was not affected at all. This shows that fasting can help reduce fat on our bodies, but will not break down muscle. The study also showed a 37% increase in the circulation of plasma adiponectin in the blood. Adiponectin is a protein hormone that aids in several metabolic processes such as insulin sensitivity and glucose regulation. It is known as being "cardioprotective" which is just another way of saying that these increased concentrations of it in the subjects' blood was beneficial for preventing CHD.
I will provide a brief summary of what I stated today. Cortisol is highest in the mornings when we wake up due to SNS and its work on the digestive system. This gives us that morning burst of energy naturally. When we give ourselves food though, it shuts this off and instead puts PSNS to work, a mechanism that usually turns on at night, and makes us sluggish and low energy. Since cortisol is high at this time, eating spikes insulin greatly, in turn also promoting high blood glucose, which is why no matter what we eat for breakfast (even eggs), we will experience a crash (or dip in blood sugar) a couple hours later and be ravenous for food.
Eating breakfast does not jumpstart out metabolism since it switches PSNS on, the system that is supposed to kick in digestion and sleepiness for bedtime. It actually slows down our metabolism, while if we hadn't eaten and continued fasting, we would see the opposite effect. Our metabolism would increase because epinephrine (basically adrenaline) is being released in response to go "search for food".
Calorie restriction has shown many benefits of increasing longevity and reducing risk factors for disease. But, this can be a painful and hard task to keep up with everyday. Instead, by restricting our eating window, but maintaining our same caloric needs, we see the same health results with intermittent fasting, without the trouble of having to restrict our food intake.
Intermittent fasting increases insulin sensitivity since we haven't been fed for a longer time (so anything we eat will be processed more efficiently) and blood glucose is very stable. This would greatly benefit diabetics who are insulin resistant and can't respond to the consumption of carbohydrates (so that bowl of cereal is doubly worse for them!). In addition, insulin sensitivity would be beneficial for diabetics because it would allow the use of adipose tissue (excess fat) to be used for energy, while insulin resistance prevents this.
On a last note, many people worry that by not eating breakfast, it will cause them to overeat later (as the claim stated). This isn't true for several reasons. When someone talks about fasting, they are not advocating caloric restriction (because as I stated above we receive the same benefits from fasting as caloric restriction eating our normal intake of food). So if we can restrain ourselves for just a few extra hours in the morning, then we can treat ourselves to brunch and eat the same amount of food we would eat for breakfast, eat a normal-sized lunch and dinner as well, just in a confined eating window. Our bodies will not allow us to over-eat because the hormone ghrelin controls our hunger so by being given the same amount of calories it would still adequately tell us when we are full.
So as we can see skipping breakfast is not going to kill us, and in fact it may benefit! Personally, I am never hungry in the morning so found the recommendation to eat quite frustrating when my body wasn't telling me to do so. It may seem hard in the beginning, but fasting really isn't that hard and I have definitely seen an improvement in alertness in my mornings (it is when I get all of my work done).
What are your thoughts? Do you have to eat your breakfast? Do you skip breakfast? Do you disagree with the notion of fasting? If so, why?
Have a great day, it is just gorgeous in Greece right now! I am going to go swim in the ocean and think about less "scientific" things. :)
NB: Anything tagged with a * or bolded like this, can be clicked on to view the study or source it came from. I wish I could pull all of this info out of my brain, but I can't. The internet is super helpful in these times!