The Breakfast Myth

By | April 30, 2013
The Perfect Breakfast?

The Perfect Breakfast?

Breakfast. The most important meal of the day.

We’ve heard this over and over again for years. So much so that it is taken for common sense. Various “experts” in the areas of health and fitness claim that it vital we don’t skip this extremely important meal. Not to mention the brainwashing we get from the barrage of advertisements for breakfast cereals, telling how they are such a healthy start to the day.

But just how important is breakfast?

You are about to discover why you DON’T need to worry about skipping breakfast.

The Breakfast Myth

This ‘breakfast myth’ is built primarily on two flawed arguments:

  1. Skipping breakfast will cause your metabolism to slow down as you are in “starvation mode”
  2. Skipping breakfast will cause you to have less energy to get through the day

Let’s examine each one.

1. Your metabolism slows down as you are in “starvation mode”

This “starvation mode” that we hear about is the state our body is in when it receives a signal that there has not been sufficient intake of nutrients for a relatively long period of time. In this state the body begins breaking down body tissue (including both fat and muscle) at a relatively fast rate in order to get hold of vital amino acids and fatty acids that are lacking because there has been no food eaten for a period of time. As we are breaking down muscle to provide the amino acids, obviously this is not a good thing.

The notion that you will go into “starvation mode” if you skip eating for more than a handful of hours is shown up as incorrect as soon as we look at some basics of human metabolism.

Before talking about this state of starvation it is important to understand that the body goes through four main metabolic states after we eat. These four states are:

The fed state: from when we eat to about 3 hours after
The post-absorptive state: from 3-18 hours after eating
The fasted state: between 18 and 48 hours after eating
The starvation state: from 2 days after up to several weeks

So when we hear someone spouting on about all the terrible things that will happen when we enter “starvation mode”, it is important to recognise that this bodily state only truly begins after about 48 hours without any food intake. This is a fact. Not my opinion, simply basic human physiology.

It is probably a fair assumption that all those “gurus” talking about starvation mode and skipping meals, are not in fact even referring to the actual starvation state and are simply throwing around clichés they picked up somewhere else.

It is more likely that they are talking about the tissue breakdown that occurs on a low level during the fasted state. However, bear in mind this will only begin after about 16-18 hours without eating. So even fasting for a full 24 hours is not really going to result in the supposed consequences of not eating relatively often, never mind merely postponing your first meal of the day for a few hours.

To think that by skipping breakfast or going long periods of the day without eating is suddenly going to cause your body to start cannibalising significant amounts of its own muscle is ridiculous to be quite honest.

The second related, but almost identical, part of this argument is that skipping breakfast (or any meal) will cause your metabolism to slow down. Yet again, if we consider the science of human metabolism we see this is not quite the case.

When someone refers to your body’s metabolism “slowing down” this refers to your body adapting and using up less energy (calories) in order to carry out the most basic of functions in order to survive. This is more accurately known as your basal metabolic rate (BMR) or resting energy expenditure (REE). Another measurement called your resting metabolic rate (RMR) is very similar to BMR but is calculated slightly differently. It serves the same purpose; to indicate how your metabolism is running at rest.

How much energy you burn in a given day will be a combination of your BMR, how much energy you use doing physical activity/exercise and how much energy your body uses to process food (thermic effect of food).

So if, as some people claim, our metabolism slows when we skip meals, our BMR will drop and so we will burn less energy/calories over the course of the day. But the science doesn’t support this.

A very interesting study that appeared in the American Journal of clinical nutrition in 2005, took 16 non-obese people and put them on an alternate-day fasting schedule for 3 weeks. So they would fast for one full day (24hr fast), eat the next day, then fast again the following day and on so on, for 3 weeks. After three weeks of this eating pattern the researchers found no difference in the RMR of the people studied.

Similarly, an earlier study found that there was no difference in metabolic rate between an overnight fast and a 3-day fast.

Skipping meals does not cause your metabolism to “slow down”.

2. Skipping breakfast will cause you to have less energy to get through the day

On the face of it this would seem pretty logical, right?

Food gives us energy, so no food equals no energy.

Fortunately, this is not the case as our bodies have extremely efficient mechanisms that allow us to function between periods of eating. It wouldn’t really make sense for us to have evolved needing to eat as soon as we got up. Humans would have spent many hours obtaining food, either by hunting animals or collecting plant materials. It is only in recent times that our species has had instant access to food at every minute of the day.

Of course, this doesn’t confirm whether eating first thing in the morning is better for us or not, but it certainly gives us a clue that we should be more than capable of coping without an early breakfast.

Most people who skip breakfast or take part in regular fasts (as in intermittent fasting) actually report that they have more energy and alertness during the fasting period. I certainly find this to be the case personally. How could this be?

Again if we consider things from an evolutionary perspective this seems logical. Our ancestors would wake up and need to go hunting or foraging for food. If they had no energy, they wouldn’t be able to do this. So surely we can feel energised even after an overnight fast. But what exactly is going on?

Well firstly, we can break down glycogen (a storage form of energy in our liver and muscles) into glucose to supply our cells with energy. These glycogen stores will probably take anywhere between a day and a week to be used up depending on a whole host of factors.

Energy can also be obtained from proteins and fats. When we wake following the overnight fast our levels of the hormone cortisol are higher than normal. Cortisol is a hormone that breaks things down. It will act to break down proteins into amino acids and eventually converting them to glucose for energy. But before you worry about muscle breakdown, these amino acids are only obtained from muscle proteins after about the 18 hour mark. Again proving that skipping meals won’t cause you to lose muscle.

Who Should Be Eating Breakfast?

Most of the points made so far are in relation to relatively healthy people. It should be pointed out that there are some people who should probably not be skipping breakfast.

These would include people with blood sugar issues; i.e. diabetes, hypo-/hyperglycaemia, metabolic syndrome and insulin resistance. Many of these people would probably be better suited to the conventional breakfast plus small regular meals through the day. At least until they have their blood sugar under control.

While fasted training can be done, I would suggest this is restricted to walking/jogging and strength training. Anything requiring a high-power output (boxing, HIIT, metcons, etc.) should probably be done with some food intake in the hours before training in order to maintain performance.

I will discuss both of these cases in more detail in my next post on intermittent fasting later in the week.

Closing Thoughts

  • I should just make it clear that I am not claiming eating breakfast is bad. I am merely claiming that not eating in the morning isn’t bad either.
  • To that end, if you feel good and enjoy breakfast then by all means continue. But if you don’t usually feel like breakfast or you need to rush out in the morning, don’t sweat it. Nothing bad is going to happen to you if you don’t eat. You may even be doing your body good.
  • There are some exceptions which I have highlighted in the above section.
  • Skipping breakfast will not cause your metabolism to slow down, your body to go into “starvation mode” or cause you to have no energy.
  • In fact, there this a lot of evidence to suggest it can do the OPPOSITE. Intermittent fasting has been shown to have a lot of potential health and performance benefits. I plan to go into more detail on this is a coming post.


What are your thoughts on breakfast?

Do you need to eat breakfast?


2 thoughts on “The Breakfast Myth

  1. Pingback: Can Fasting Work for You? » Metabolic Perfection

  2. Pingback: Insulin and Diet (Part One): What Does Insulin Do? » Metabolic Perfection

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