You’ve been working hard in the gym. Lifting smart, training hard, and trying to keep your diet on track – yet those pounds are not coming off and those muscles are not showing up the way you want. If this is you, you’re not alone.
What do you do? You start looking for how to lose that extra fat without sacrificing your hard earned muscle, and you find references to intermittent fasting all over the internet. Drop pounds, loose weight, preserve muscle, and all the other aspects are there – and yet, despite so much published on the topic, there still seems to be a good deal of confusion on what this is, how and why it works, and how to do it.
CoreTek Fitness understands the confusion – and as always, we want to give you sound and clear advice to support your goals and see you achieve your fitness potential. So buckle up, as we are about to give you the scoop on intermittent fasting.
Let’s start with the science:
Intermittent fasting is not a diet, it’s a pattern of eating. It’s a way of scheduling your meals so that you get the most out of them. Intermittent fasting doesn’t change what you eat, it changes when you eat.
Intermittent fasting works by working with the body’s natural physiological and chemical responses to being in either a fed or fasted state. Also, think of your body as having two tanks of fuel – primary and reserve. The primary is from the food you eat; the reserve is fat.
Your body is in the fed state when it is digesting and absorbing food. The fed state starts when you begin eating and for most people lasts for three to five hours as your body digests and absorbs nutrients from this food. When you are in the fed state, it’s very hard for your body to burn fat because your insulin levels are high. Or simply, your body never needs to touch the reserve tank, because the primary tank is always full.
After that digestion and absorption period, your body goes into what is known as the post–absorptive state – simply put, your body isn’t processing a meal. The post–absorptive state lasts until 8 to 12 hours after your last meal. Only after this, does your body enter the fasted state. At this point, for energy, you body is turning to that reserve tank – fat – for its energy source.
In this fasted state, your body can burn fat that has been inaccessible during the fed state.
If you consider most people’s meal schedule, and that we don’t enter the fasted state until 12 hours after our last meal, it’s rare that our bodies are in this fat burning state. This is why many people who start intermittent fasting will lose fat without changing anything in their diet or exercise routine. Fasting puts your body in a fat burning state that you rarely make it to during a normal eating schedule.
Moreover, a study by the National Institute on Aging (NIA) suggests that intermittent fasting could be the key to longevity.
A group of scientists from the NIA, the University of Wisconsin-Madison and the Pennington Biomedical Research Center in Louisiana found that increasing time between meals improved the overall health of male mice and lengthened their lives compared to mice that ate more frequently. Health benefits were seen regardless of what the mice ate or how many calories they consumed.
Another study by the Longevity Institute in 2015, also conducted with mice, found that four days of a diet that mimicked fasting extended lifespans, lowered visceral fat, reduced cancer incidence and rejuvenated the immune system. The study later saw similar reductions in disease risk factors in humans.
How to Conduct Intermittent Fasting:
As you can tell by now, the goal of intermittent fasting is to get your body to go at least 12 hours without food, and then have to exert some level of energy. Whether this is your normal job, house errands, or working out – you need to burn energy in this state. There is no one specific ratio everyone needs to follow – you will need to do what is best for you. Above all, remember that fasting offers infinite flexibility. You can fast for as long or short as you like, but here are some popular regimens. Generally, shorter fasts are done more frequently.
16:8: This involves daily fasting for 16 hours. Sometimes this is also referred to as an 8-hour eating ‘window’. You eat all your meals within an 8-hour time period and fast for the remaining 16 hours. Generally, this is done daily or almost daily.
For example, you may eat all your meals within the time period of 11:00 am and 7:00 pm. Generally, this means skipping breakfast. You generally eat two or three meals within this 8-hour period.
20:4: This involves a 4-hour eating window and a 20-hour fast. For example, you might eat between 2:00 pm and 6:00 pm every day and fast for the other 20 hours. Generally, this would involve eating either one meal or two smaller meals within this period.
Key Points to Remember When Fasting:
- Listen to your body – if you are feeling tired, sluggish, not well, hungry, etc – then eat! Yes, there is going to be an adjustment period to any fasting schedule you will need to push through, but we are not talking about this. If your body is giving off alarms – break the fast!
- You will maximize the your body’s use of fat by exercising fasted. This is when your body will need the most fuel for exercise and recovery.
- You still need to consume your full macronutrient balanced calorie levels. As we said, intermittent fasting is about when to eat, not what to eat. So if you need 2,400 calories a day, then you still need 2,400 calories a day – you just have less time to consume it.
Who should NOT fast?
You should not fast if you are:
- Underweight (BMI < 18.5)
- Pregnant – you need extra nutrients for your child.
- Breastfeeding – you need extra nutrients for your child.
- A child under 18 – you need extra nutrients to grow.
You can fast, but may need supervision, under these conditions:
- If you have diabetes mellitus – type 1 or type 2.
- If you take prescription medication.
- If you have gout or high uric acid.
Commonly asked questions for those interested in trying intermittent fasting:
Will fasting burn muscle?
No. During fasting, the body first breaks down glycogen into glucose for energy. After that, the body increases fat breakdown to provide energy. Excess amino acids (the building blocks of proteins) are also used for energy, but the body does not burn its own muscle for fuel.
Isn’t it important to have breakfast every morning?
No, it’s not. This is an old misconception based on speculation and statistics, and it does not hold up when it’s tested. Skipping your morning meal just gives your body more time to burn fat for energy. Since hunger is lowest in the morning, it is often easiest to skip it and break your fast later in the day.
Isn’t fasting the same as reducing calories?
No. Not at all. Fasting reduces the time you spend eating and addresses the question of ‘when to eat’. Calorie reduction addresses the question of ‘what to eat’. They are separate issues and should not be confused with each other.
So there you have it – intermittent fasting. It’s really that simple. Will it work? Most likely, yes. Will you see amazing weight loss? As CoreTek points out with all of its advice – every body is different. How well you respond will depend on your body, your workouts, your overall diet, etc. You will never out-train, or out-fast a bad diet and excessive caloric intake.
What we do recommend is do your research on this, as you should before starting any exercise or meal management program – we have additional reading recommendations below. And ease into it. You do not have to fast every day to start. Try 2-3 days a week for 2-3 weeks. If you are able, add more days. Remember, this is about what works for you. Realistically, it will take about a month for you to have a fair assessment of how the program is affecting your fat loss. And always, if you have medical issues, seek a physician’s advice first!
