Is skipping breakfast a good idea? How your genes may hold the answer

By Lumminary Team, 27 Aug, 2018

Are your genes the key to fasting success?
Intermittent Fasting Origins
Intermittent Fasting Methods
What does IF hope to achieve?
Safe Ketosis
So what are the health benefits of IF?
Why skipping breakfast is healthy. The science version
Genes, Hunger, and Mood
Ketosis and Genes
How a DNA test can help you stay slim
When to avoid fasting

Are your genes the key to fasting success?

Much has been talked about intermittent fasting (IF). I’ve advocated it and followed intermittent fasting for more years than I care to mention.

I noticed that to a point, I operate without food perfectly well, fully focused, and painlessly. While I’ve noticed others are falling by the wayside desperate for their next meal, energy levels on the floor with terrible hunger. So what’s going on? Do different people experience hunger differently?

IF is certainly a big change to a standard that is often followed in nutrition circles of eating three meals a day with snacks in between. Eating six small snacks and grazing has also become popular in some circles. Above all, breakfast aptly named as the morning meal that breaks your “overnight fast” as you sleep - has been touted as the most important meal of the day by many for years.

“Breakfast like a king, lunch like a prince and dine like a pauper,” has been hailed as a great way to stay in shape. And an all around healthy way to avoid you “storing” your evening meal as fat.

I never bought into that with my understanding of how our bodies use energy and, fortunately, there is now plenty of scientific evidence to back up why IF is considered healthy.

In this 101 Beginner’s Guide to IF, we give you evidence-backed data to the various health claims you may have heard.

We also unravel how our genes affect how different people respond when they fast. Moreover, we go into why you should take a DNA test before you decide if IF is right for you.

But first of all, what is the big idea with intermittent fasting?

And what is it exactly?

Intermittent Fasting Origins

Fasting intermittently on and off is pretty self-explanatory. The idea goes back to our ancestral way of eating.

The fact that food is readily available to us now in Western societies is a far cry from how we evolved to eat.

Our hunter-gatherer ancestors were quite used to a famine and feast style of eating. Those that could pack on fat stores after a feast with what has been dubbed the “thrifty gene” were far better suited for survival.

Now it must be noted that our ancestors fasted out of necessity. But many people are now choosing to fast intermittently as a favored way of eating with several health benefits.

So how do you fast intermittently, exactly?

Intermittent Fasting Methods

Mainstream IF has three main methods:

  • The 16/8 method is where you fast for 16 hours each day and eat all your food within an 8-hour time frame. It doesn’t matter how you achieve this but the usual method is to just extend your fast by skipping breakfast. Then all you have to do is eat from say 12-8 pm, for example.

  • The Eat-stop-Eat requires a 24-hour fast but you would only do this once or twice a week maximum. You could achieve this by fasting after dinner one evening through to the next dinnertime.

  • The 5:2 diet is a method where you drastically undereat on two days out of seven. You only eat around 500 calories on these two days and eat normally on the other five days.

What does IF hope to achieve?

Well, first and foremost, with it being a style of eating, it does aim to achieve weight loss or maintenance.

And all the methods should work with weight loss assuming you don’t go crazy when it’s time to eat. Remember, weight loss through IF doesn’t work by magic, it works on the same principles as any other diet - calories in versus calories out.

The 16/8 method is what I have done for years and is the most popular way to fast. Finally, those who are not into breakfast and can charge through a morning’s work fully focused with a coffee and an occasional stomach groan are at last being vindicated by a mountain of research and hard data.

While some may prefer to get energy directly from food every few hours, intermittent fasters know that they’ll survive. So what happens exactly when you fast? Where does your body get energy from?

The answer is pretty simple. Your fat stores. The human body has a fairly low limit for storing glucose. The body can only call on a limited amount of glucose (about 80 calories) and glycogen (around 480 calories).

So when that’s gone. Your body will need to burn fat. Enter ketosis.

Safe Ketosis

Ketosis or the state of using fat and fat stores for energy is now considered to be a kind of nutritional nirvana. Yet previously ketosis was considered to be a serious condition possibly indicative of major health problems.

In reality, doctors know diabetic ketosis is dangerous while nutritional ketosis is regarded as safe and beneficial for various reasons.

Nutritional ketosis is for the most part associated with ketogenic eating. Keto eaters achieve nutritional ketosis by virtually eliminating carbohydrates. Protein is not used by the body for energy, and excess that is not needed by our bodies is excreted. That just leaves fat for the body to use as energy. Thus, ketosis is a given.

However, a ketogenic diet which denies carbohydrates is by definition a high fat diet.

The jury is out without sufficient current data surrounding the safety of a high fat diet. Keto advocates say the information and data about cholesterol and saturated fat causing heart disease is wrong. They say heart disease hasn’t been a problem until refined carbohydrates have been added to the typical Western diet in the twentieth century.

Which is great if keto eaters are right. But their healthy evidence-backed ketosis comes at the cost of their unproven high-fat, high-cholesterol keto diet.

The intermittent faster takes no such risks. Not just that, the level of ketosis achieved with IF is far greater.

Ketogenic diets can increase ketones fourfold but IF has been shown to increase ketones by up to twenty times . IF is therefore thought to have a far greater benefit. It also saves you the time and trouble of trying to make a pizza base out of a cauliflower like the keto eater.

So what are the health benefits of IF?

The health benefits of IF read like the sales page of a miracle supplement but they are backed by empirical evidence. So aside from weight loss, IF also improves cognitive function, boosts metabolism, improves blood sugar control, lowers blood pressure, reduces inflammation and makes you live longer. It may also reduce your risk of type 2 diabetes, heart disease, and cancer.

And it’s free.

Let’s look at these benefits in a little more detail.

Why skipping breakfast is healthy. The science version

Weight Loss

Intermittent fasting has been proven to help both healthy and overweight adults lose weight effectively in various studies. In human trials with non-obese patients and alternate day fasting virtually all the participants experienced weight and fat loss. As long as you don’t overeat as soon as your fast is over then you’ll either lose weight or likely find it easier to manage your weight.

Improved Fat Burning

The effects of intermittent fasting and metabolism are still being investigated but it’s thought that intermittent fasting may actually increase the basal metabolic rate by up to 14%. This is in stark contrast to diets that are thought to reduce the metabolic rate as the body adapts to the threat of starvation.

Decreased Blood Pressure

IF can improve heart health in a number of ways. In a study of fasting on obese patients, the study showed a significant reduction in blood pressure. IF has also been shown to improvements in total and LDL cholesterol levels.

Improved Cognitive Function

IF improves many factors which are beneficial to brain health such as a reduction in blood sugar levels, oxidative stress, and inflammation. In addition, IF increases neuronal autophagy which can improve brain function and improve focus.

Blood Sugar Control

In human trials, intermittent fasting was found to reduce blood sugar and insulin significantly. It can, therefore, reduce the risk of developing type 2 diabetes.

Reduces Cancer and Alzheimer’s Risk

IF induces autophagy or cellular repair. It is thought this not only improves brain health and the risk of Alzheimer’s but also may help protect against cancer.


There aren’t any current human studies that have been conducted with people to truly assess longevity claims however with other health markers being improved it’s likely to be the case. In studies on rats, the fasted rats lived on average 83% longer.

These are some of the health reasons attracting IF devotees. But you may be more or less suited to IF depending on your genes.

Genes, Hunger, and Mood

It’s all very well to say that everyone gets hungry when we’re fasting but that’s not the whole picture. As with everything in life, things affect us differently and we experience things differently. Hunger is no different. In a study by researchers, 108 patients were given a diet of just 350 daily calories and their hunger and mood were recorded.

The researchers were studying the GNB3 gene or thrifty gene often associated with obesity. They concluded that those with the CC genotype experienced the best mood with least hunger and the TT genotype had the worst mood with most pronounced hunger. With the CT genotype falling somewhere in between.

What genotyping do you think you might be?

Ketosis and Genes

As we explained, when your body depletes its glucose and glycogen, fat is be used for fuel instead and you go into ketosis. For most people, this is no problem but some people carry a genetic variant that makes getting into ketosis difficult.

The mutation is known as the SCADD or MCADD and relates to a deficiency in short and medium fatty acids. Carrying both mutations can cause a serious health problem and is detected and managed at birth.

However, having just one mutation will go undetected but can still cause less serious issues. Those with a single mutation may also have a poor response to fasting and may be prone to hypoglycemia.

It’s thought that this may affect around 1 in 100 people.

How a DNA test can help you stay slim

In the past and often currently we use trial and error when it comes to medicine and diets. Yet in this data-driven age, we know that the information contained within our own DNA is going to be the driving force behind vastly improved healthcare.

A genetic test helps you make sense of your dieting successes and failures. Think about it, we all try out different things we hear about it, some things seem to work great for us and other things not so great. So, we record those perceived results and try to battle on with what we’ve learned. A DNA test can help you bring greater understanding to what you think might be the case.

A test will also give you loads more information, such as how your body responds to consuming carbohydrates, fats, and proteins. You’ll also find out foods to avoid and any deficiencies you may be at risk of. Armed with information about how best to eat to lose weight you are far more likely to succeed.

It can give you more information about all kinds of things, including if you are a carrier of the SCADD or MCADD mutation. You can also find out what genotype you are and how fasting may affect your hunger and mood.

IF is easy

The great thing about IF is how simple it is.There is no apparatus to buy, no book of foods indexes to learn, nobody wants any money from you, there are no recipes or must-have ingredients.

Most intermittent fasters follow the 16/8 method. Other methods are painful in that virtually everyone will become very hungry and that makes life quite unpleasant...

But most find that 16/8 fasting requires no real effort. It’s essentially skipping breakfast every day. There’s one less breakfast dish to stack in the dishwasher. Nothing could be easier.

When to avoid fasting

Regardless of genetic tests, intermittent fasting is not right for some people. It is not right for people who are underweight, it is also not a suitable method for women who have fertility issues that are trying to conceive. While no direct studies have been performed with humans, fasting has been known to cause changes to and even cessation of the fertility cycle.

Because fasting is a feature of the eating disorders, anorexia and bulimia nervosa it is therefore also a trigger, so those with a history of eating disorders should avoid IF.

It’s also recommended that children don’t fast as well as those who are sick or recuperating.

You should also consult your doctor if you are taking medications, have diabetes, are underweight, have low blood pressure, are pregnant or breastfeeding.


We are all very different creatures and no single solution works for everyone but intermittent fasting is certainly a lifestyle worth considering.

It’s certainly easy to follow and can help people lose and maintain weight effectively. There are certainly a number of proven health reasons already associated with IF including reduced blood pressure and improved brain health. It’s also thought that IF can protect you against a number of diseases.

However, as we have learned different people respond differently to fasting. Taking a DNA nutrition test will allow you to predict if and how well you can tolerate intermittent fasting. It may be that while most people can tolerate IF it could be too stressful for the approximately 1 in 100 people with the MCAAD/SCAAD mutation.

Others with a CC genotype may also struggle even with the 16/8 method. You will still benefit by extending the 16/8 to 15/9 as best you can manage. But hey, IF isn’t for everyone!

A DNA test will also give you a range of easy-to-understand information so you can better plan your nutrition and lifestyle. You’ll therefore be able to optimize your health and have a greater chance of achieving any weight loss goals.

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