Why the science of intermittent fasting makes sense
Most of us have been raised to know that ‘breakfast is the most important meal of the day. However new science is emerging which is contradictive to this.
Moreover breakfast, in particular the wrong kind of breakfast, could be causing more harm than good; from stimulating our hunger hormone (ghrelin) leading to an increase in calories, to reducing Human Growth Hormone (HGH) which helps build muscle and keeps us young, and desensitising us to insulin contributing to myriad of chronic diseases including diabetes, some cancers and cardiovascular disease.
Scientific evidence is pointing towards the health benefits of skipping breakfast, a practice called Intermittent Fasting (IF), whereby meals are kept within a 6-8 hour eating period across 24 hours. This is usually practised two or more times a week and is best practised most days. This science banishes the old-school belief that six small meals a day is beneficial.
A scientific review in the British Journal of Diabetes and Vascular Disease published by SAGE, concluded that intermittent fasting offers the potential to improve weight loss and enhance cardiovascular health of overweight and obese individuals with Type 2 diabetes, and reduce cardiovascular risk.
Humans have actually evolved practising IF. It is only in the past 150 years that food has become more abundant.
Previously our ancestors ate one to two main meals a day. This fluctuated over famine and feast months. Humans are designed by nature to have fluctuations in caloric intake. In fact when we are fasting our body sets about repairing and healing itself. Your body was built for periodic cycles of feast and famine.
The science of IF demonstrates health benefits to:
Normalise fat hormones such as ghrelin, the hunger hormone. Ghrelin is stimulated in the stomach to signal the brain to eat. It reminds you that you are hungry.
However what’s interesting about ghrelin is that it changes its circadian rhythm (its naturally fluctuating levels) depending on your eating habits. If you are used to eating six meals a day, ghrelin will alert you if you skip a meal by telling you that you’re hungry.
If you are used to eating breakfast, then you will be hungry at breakfast time. However it only takes a few days to change the rhythm of ghrelin, meaning it’s easy to change eating habits over just a few days.
Increase levels of Human Growth Hormone (HGH), also known as the Youth Hormone.
Fasting stimulates HGH which keeps us young and helps repair the body and build muscle, both important for athletes and those of us who want to stay youthful.
So one argument for skipping breakfast, especially before your morning workout, is that it will result in higher HGH levels, leading to a more productive workout. It can also slow the ageing process and HGH itself is a fat-burning hormone, so higher levels result in more fat loss.
Improve cardiovascular health
In fact IF could be as beneficial as exercise for improving cardiovascular biomarkers by normalising blood pressure, heart rate and cholesterol ratios.
Restore leptin and insulin sensitivity.
This can be useful for those struggling with weight or blood sugar issues such as diabetes.
Reduced oxidative stress, slowing ageing
Fasting decreases the accumulation of oxidative radicals in the cell, and thereby prevents oxidative damage to the cellular proteins, lipids and nucleic acids associated with ageing and disease.
How to practise IF
There are a number of ways to practise intermittent fasting. Two common methods are to restrict eating hours to a six to eight hour period over 24 hours. An example of this would be having the first meal at noon and the last meal before 6pm or 8pm. This is how I eat most days. It is recommended to practise this at least twice a week.
The second common way is simply to have one 500 calorie meal for women and 600 calorie meal for men, and nothing else twice weekly. Of course what you eat is also important to nourish the body. A healthy nutrient dense and higher fat diet on the other five days will optimise wellness and work well with the practice of IF.
But isn’t breakfast the most important meal of the day? If not, why?
Breakfast doesn’t increase your metabolism. Humans need to fast for more than 72 hours/3 days before a slight 10 percent drop in our metabolism is induced. IF or skipping meals does not negatively impact metabolism.
Breakfast may not have a positive effect on your blood sugar levels.
Common advice is that breakfast better controls blood sugar and insulin levels. This would depend entirely on what you eat not only at breakfast but across the day. Insulin is important for muscle growth, however it is also responsible for fat storage. Fasting reduces insulin levels and increases insulin sensitivity dramatically more that eating small frequent meals. This is why people with diabetes report better management of blood sugar levels when using Intermittent Fasting techniques.
Breakfast doesn’t prevent muscle loss and fasting doesn’t burn muscle. This is the starvation myth. Eating every three hours has not shown to increase muscle mass or prevent muscle loss. Eating protein around your training appears to have more effect on muscle mass than your total protein intake across the day. In other words it’s when you eat in relation to your exercise that matters, not drinking a protein shake with breakfast.
Breakfast makes you hungry. If you want to gain weight then eating breakfast is essential as it raises blood sugar levels and once the stomach empties it stimulates ghrelin, the hunger hormone that tells you to eat and make you eat more across the day, not less. If you want to lose weight then skipping breakfast can regulate ghrelin, leading to fewer calories across the day.
Breakfast isn’t part of human evolution. Our ancestors very likely didn’t eat breakfast, certainly not the kind or breakfast we have. Breakfast means ‘to break the fast’ and given that our ancestors didn’t have supermarkets or convenience stores, breakfast cereals and toast was not something readily available. All food was cooked from scratch just 70 years ago.
Breakfast doesn’t make us smarter. Eating breakfast before work will does not increase our level of concentration. In fact studies have shown that fasting in the morning may increase mental alertness, and people report feeling more productive and motivated across the day when they skip breakfast.
It’s important to note that this may not apply to children as their brains are still growing and they tend to eat a more carbohydrate rich diet which in itself calls for more regular meals and snacks. However mental alertness from fasting could come from Palaeolithic man who when hungry has to have energy to hunt and provide food for survival.
So is skipping breakfast and IF for everyone?
No. What works for one person will not work for another, and any dramatic dietary change should be done under supervision from your healthcare professional trained in nutrition. While fasting is generally safe it is not recommended for those who suffer with hypoglycaemia, so it’s important to ensure you have healthy blood glucose levels to start with. If not, begin by working with a nutritionist to ensure you normalise blood glucose first through proper eating. Likewise, if you have adrenal fatigue or are living with chronic stress then it is best to avoid fasting. And naturally if you are pregnant or breast feeding then fasting is not recommended.
The lifestyle of practising Intermittent Fasting (IF) is often combined with a lower carbohydrate/higher fat diet inducing Nutritional Ketosis, or the ketogenic diet. (See November 2014 Issue of Fitness Journal)
Long before IF became ’trendy’ I have personally practised two key nutritional principles: I have spent most of the last decade on a low carb, higher fat diet resulting in Nutritional Ketosis (NK), and I skip breakfast several times a week practising IF. So the regulation of my ghrelin and my natural HGH levels would be different from someone who eats six meals a day. Any transition to this way of eating should be done slowly. For me now I am rarely hungry and when I am it is appropriate.
So has this style of eating worked for me?
When I started I was Insulin Resistant with high LDL cholesterol, chronically high cortisol and my weight constantly fluctuated. I craved sugars and carbs and would fall asleep mid-afternoon.
More than a decade later after my lifestyle change I have a BMI of 21 and a biological age of a woman 10 years younger. All my biomarkers have normalised and for a woman in her 40s my weight hasn’t fluctuated more than a few kilos in years.
So if you are struggling to maintain your energy levels across the day, or struggling with your weight, consult an expert in NK and IF to see if it’s right for you. After coaching thousands of people through these types of programmes, I personally believe this approach to eating is worth investigating to see if it’s right for you.
Deborah Murtagh has more than 20 years’ clinical experience in weight loss and natural health.
Deborah founded Whole Food Secrets, an online nutrition and cookery school offering online programs in nutrition and weight loss, and has a thriving nutrition consultancy dedicated to ketogenic dietary protocols for athletes, weight loss, cancer and chronic diseases. www.wholefoodsecrets.com