Intermittent Fasting Diet
by Sue Kira, Naturopath & Clinical Nutritionist
Generally, people in westernised societies eat too much, too often, choose foods low in nutrition, and do not give their bodies enough time to recover between meals. No wonder there is so much illness and disease, which unfortunately could have been prevented in most cases.
Is it right to eat three meals a day? Is western society just following a collective unhealthy habit that developed over time? Mmmm…perhaps intermittent fasting is a more natural and healthy way of eating for our bodies.
In my opinion, this style of eating is by far the most successful, sustainable, and manageable way to lose weight and adopt for better health, more energy and vitality.
This is not the ‘starve yourself for long periods of time’ type of fasting regime, but more about having elongated gaps between meals. The spacing of meals allows time for the body to do repair jobs, process food eaten previously, cleanse the system, discard waste and more importantly, use fat stores for energy rather than deposit fat where it is unwanted, such as your arteries or waistline.
It seems that the body doesn’t start to burn fat for fuel until 12 hrs has past, which means that our normal overnight fast from dinner to breakfast (say from 7pm to 6.30am) usually doesn’t allow enough time to get the metabolism rolling. But if you have a 16hr gap, then your body will burn fat for those extra 4hrs.
There are various versions of this type of ‘fasting’ discussed in various health circles. The two main ones are the 5:2 diet, which is where you eat normal healthy food three or so times per day for 5 days per week and have two days per week where you eat one meal of around 500 calories (2092 KJ) for women and 600 calories (2500 KJ) for men, at any time of the day that suits you best.
The other style of intermittent fasting uses the principle of eating only two meals a day with one 8hr gap and one 16hr gap. For example, you may have brunch at 11am and dinner at 7pm. This becomes a regular daily event. These hours can be altered to suit your work and lifestyle habits e.g. a shift worker might eat at 10pm and 6am.
According to research, the number of calories eaten in this style of fasting doesn’t seem to matter. But eat what feels comfortable for your body and workload, and drink plenty of water or herbal teas to keep your fluids up to help your liver and kidneys flush out toxins.
If you are trying to lose weight, you can use this diet to have less calories overall. You may wish to keep your calories around the 500-600 mark (per meal) depending on your weight, height, and energy needs. Speak to your practitioner so you know what will serve you best.
Some people like to have alternate days of eating three meals one day and one to two meals the next which works for them.
One client loved to have a complete fasting day once a week, only drinking water and herbal tea. He ate dinner on Saturday night, then no solid food till breakfast on Monday – a total of 36hrs of fasting. He reported feeling very energised and ready for the working week. He didn’t relax all day as you might expect, instead he did lots of fun things like bush walks, swimming, kayaking, surfing, and playing with his grandchildren.
It’s important to realise that intermittent fasting is not an excuse to eat ‘rubbish’ food on your fasting days. You need to choose healthy balanced meals. In fact, if you are not eating as many calories as normal, it is more essential to eat nutrient dense meals.
Research on mice has shown that these fasting styles of eating: reduce cholesterol, blood pressure, fat mass, cancer and heart disease risk; and increase energy, lean muscle mass and longevity (the mice studied were reported to live the equivalent of an extra 20-30 human years).
More studies need to be done on humans, however some studies have shown good results regarding health risks such as cholesterol, blood pressure, lean muscle, fat mass and energy levels, but it is too early to see if it has helped in areas such as cancer and longevity.
Consult your health practitioner to determine what suits you and once you get the all clear, you may try both types of intermittent fasts to see what works best for you.
At first it may feel strange, but it is quite easy. Initially belief systems were running through my head as I thought I would feel starved or weak, but I surprised myself that it’s not difficult at all.
Intermittent fasting can have a positive effect on our cells, genes, and various hormones
When you don’t eat for an extended period, it gives the body the opportunity to make hormonal shifts such as:
- Insulin levelsdrop which facilitates fat burning.
- Human growth hormonemay increase as much as 5-fold. Higher levels of HGH facilitate fat burning, muscle gain, plus other numerous benefits.
- Cellular repairincreases along with increased removal of waste material from cells
- Gene expressionand molecular changes relating to longevity
- Protection against disease increases
Intermittent fasting can help you to lose weight
Many who try intermittent fasting do so to lose weight. In most cases this works because you eat less meals and hence fewer calories, provided you don’t ‘overfill’ in those meals.
As seen above, intermittent fasting also enhances hormone function to facilitate weight loss by lowering insulin levels, increasing higher growth hormone levels and increased amounts of norepinephrine (noradrenaline) which all increase the breakdown of body fat to facilitate its use for energy.
Short-term fasting can increase your metabolic rate by up to 14%, helping you to burn even more calories. In other words, intermittent fasting boosts your metabolic rate and reduces the amount of food you eat.
But on the other hand, fasts that are super low calorie or water fasts, can drop your metabolism as the body tries to conserve energy.
Intermittent fasting can lower the risk of type 2 diabetes
Because intermittent fasting can reduce insulin resistance and blood sugar levels, it can be useful to prevent type 2 diabetes.
Intermittent fasting reduces oxidative stress and inflammation
Oxidative stress involves unstable molecules called free radicals that react with protein and DNA in the body and create damage. Several studies show intermittent fasting may support the body’s resistance to oxidative stress. Studies also show that intermittent fasting can help to reduce inflammation, which helps to prevent numerous diseases and slow down the body’s aging process.
Intermittent fasting is beneficial for heart health
It is known that various risk factors are associated with heart disease. Studies have shown that intermittent fasting can improve certain risk factors such as blood LDL cholesterol, triglycerides, blood pressure, inflammatory markers, and blood sugar levels
Intermittent fasting may reduce the risk of cancer and may support cancer treatments.
It will be great to see more human studies, but evidence from animal studies show intermittent fasting may help to prevent cancer. There is also some evidence from cancer patients that this type of fasting has reduced various side effects of their chemotherapy treatment.
A practitioner I know of employed a fasting regime where she only ate one healthy meal a day in the four days leading up to, and during, her chemo treatment days. The rest of the time she had two healthy meals a day. She did not get any side effects from the treatment and had heaps of energy and felt great, unlike those around her at the hospital who were getting the same treatment.
You could put it down to pure luck that she didn’t get any reactions, but for one treatment her chemo schedule was messed up and she had to have her treatment on a different day without available time for prior fasting. She felt really sick, lethargic and toxic for several days. But when she got back on track with her intermittent fasting regime, she had no more sickness from future chemo treatments.
Her type of cancer was considered very aggressive and not very responsive to chemo. But it was suggested to try it anyway, and she was given super high doses to do what they could for her stage 4 breast cancer.
With the adjunctive treatments of healthy eating, intermittent fasting and chemotherapy, she was in remission after six months of treatment from a cancer that her doctors had given her a small chance of surviving. It is still too early to see how she will go long term but all the signs are good.
Intermittent fasting for a healthy brain
Many studies have shown that good brain health features such as reduced oxidative stress, reduced inflammation, and reduced blood sugar and insulin resistance, have improved with intermittent fasting.
Exciting studies show that intermittent fasting helps to support the increase in growth of new nerve cells in the brain as well as increasing levels of a brain hormone called brain-derived neurotrophic factor (BDNF). BDNF deficiency has been linked to depression and various other brain problems.
Intermittent fasting may reduce neurodegenerative diseases
In a series of case studies, intermittent fasts were shown to significantly improve Alzheimer’s symptoms in 9 out of 10 patients. Some very positive animal studies have suggested that fasting may protect against other neurodegenerative diseases, including Parkinson’s and Huntington’s disease.
Intermittent fasting may extend lifespan
Studies in rats have shown that intermittent fasting extends their lifespan by the equivalent of 30 human years. Rats that fasted every other day lived 83% longer than rats that did not fast. While we are not rats it still looks promising. There have been studies on other animals, but not much on humans yet.
You may think hunger is the first side effect you would feel from intermittent fasting, but commonly people don’t feel hungry. Some feel a little weak or their brain might not function as normal until the body adapts to the new meal schedule. If you have any medical conditions, then you should speak with your doctor before starting an intermittent fast diet, particularly if you have any of the following conditions.
- Low blood pressure
- Taking medications – check with your doctor first
- Pregnant or breastfeeding
- Female trying to conceive
- Female with a history of amenorrhea (absent periods)
- Have a history of eating disorders
Intermittent fasting does have a good safety profile according to studies and there is nothing ‘dangerous’ about not eating for a while if you are healthy and well nourished. But if you try it and it doesn’t feel right, then discontinue this diet regime.
Isn’t it supposed to be unhealthy to skip breakfast?
No. If you ensure you eat healthy food for your other meals of the day, then it is totally fine to miss breakfast.
Can I take supplements while fasting?
Yes. But some supplements (like fat-soluble vitamins) and medications that are prescribed to take with meals work better with food. If you feel sick from taking your supplement or medication on an empty stomach, take supplements with a meal, say your brunch.
Will fasting cause muscle loss?
All weight loss methods have the potential to cause muscle loss, but one study showed that intermittent fasting causes less muscle loss than regular calorie restriction.
Will fasting slow down metabolism?
No. Studies show that intermittent fasting boosts metabolism, whereas longer fasts of three full days or more, especially if just water, can reduce metabolism.
Should kids fast?
No, it is not advisable for children to fast, unless medically prescribed.
Many people instinctively eat this way. They simply don’t feel hungry in the morning and eat at mid-morning or lunchtime. Some people find it suits them to simply skip meals from time to time when not hungry.
The best diet is the one that suits you and your body – but only when you consciously feel what your body needs, rather than starve yourself simply because you couldn’t be bothered to eat or prepare something healthy.
There is no need to follow a structured intermittent fasting plan to derive at least some of the benefits, but if you prefer structure, then the 16hr/8hr method may suit you best.
You may like to choose recipes that have a higher calorie value, such as 600-800 calories for example and eat two of these a day or eat a higher calorie meal at dinner if that works better for your schedule.
You may need a higher amount according to your weight, hunger needs and the type of work or exercise you do. But you don’t have to count calories at all – just have the serving size and meal type that feels right for your body at that time.
If you feel hungry, then the addition of more fats/oils such as coconut cream/oil, avocados, or nuts with healthy fats such as macadamias with your meals can help. This is also useful if you want to keep your calories up but still gain the benefits of intermittent fasting.
Plenty of good fats, moderate protein and low sugar carbs are best for your meals. If you crave starchy carbs like pasta, choose gluten free pasta for the late meal as carbs tend to make you sleepy. This is best for nights rather than be tired during the day (and that way you don’t blame the fast for fatigue, when it’s the carbs).
Stay away from meal choices with sugar, as sugar makes you hungry, tired and crave more sweet things.
Experiment with different approaches to see what works best for your schedule and food preferences.
Before you commence your diet, see your medical or health care professional for qualified guidance about what foods and supplements are best for your body. While on the diet do not stop any medications or supplements previously prescribed unless advised otherwise by your medical or health care professional.
During the early stages of a new diet, you may experience symptoms such as fatigue, headaches, or body aches, which may occur because your body is detoxifying. However, if you are unsure about a symptom at any time, check immediately with your medical or health care professional.
Client name and identifying information changed
When Kim came to see me, her main purpose was to lose weight. She tried all sorts of diets over the years, but none shifted the stubborn weight that she had around her middle. Belly fat can be due to either cortisol levels being high from stress, or from insulin issues (too much sugar not being processed properly).
We tested her cortisol levels, thyroid, digestive system, and mineral levels. All appeared to be fine. It seemed her main issue was insulin control.
Kim did not add sugar to anything such as coffee. But she loved chocolate and sweet treats, so she was in fact consuming sugar most days. A couple of years previously she tried going off sugar and even fruit. While this stopped her weight increase she didn’t lose any weight which depressed her, so she gave in to her cravings.
We discussed how chocolate cravings related to magnesium deficiency and if she had a fungal overgrowth like candida she would crave sweet things. But tests showed that these were fine. So it just came down to addictions and emotionally filling an inner emptiness.
We discussed this and Kim told me how she previously had issues relating to a lack of self-worth or appreciation, and she used chocolate as an emotional crutch. She said her feelings of self-worth had changed for the better, but she didn’t kick her chocolate addiction.
We then discussed trialling an Intermittent Fasting Diet to see if it would help her to lose that stubborn weight – and she also needed to stop the sugar.
An intermittent fast program is not about cutting out calories so you can replace them with chocolate and sweets.
For Kim, the intermittent fast concept was quite easy as she was never hungry in the mornings, although she forced herself to eat breakfast because she thought it was the most important meal of the day. She would have preferred to eat around 10 or 11am with a large meal and then a lighter meal at dinner time.
I suggested trying this and make sure that she ate a healthy, nutritious meal for brunch and dinner with no snacks of chocolate or anything else so her digestive system could have the rest it needed, and her fat stores would supply the energy.
Each meal was around 500-600 calories so her daily total was around 1100-1200 calories. That way she could gradually lose weight each week.
Eating this way not only reduced her calories, but also gave her better insulin control so her body wasn’t trying to store fat and instead, use her fat stores to run her body in the mornings.
Kim came back to see me after three weeks of intermittent fasting using the 16hr/8hr method. She had brunch at 11am and dinner at 7pm, so her body had a 16hr fast overnight and an 8hr break during the day.
This was easy for Kim – she loved not having to deal with breakfast as this was usually a busy time getting ready for work, and she said she was half asleep at that time anyway.
She ate brunch at her designated morning tea-time and skipped her lunch break which made her more productive at work. For dinner at home she prepared a nourishing meal with extra protein (chicken, meat, egg etc) to go with salad for next day’s brunch.
Psychologically, Kim thought the intermittent fasting would be hard, but she said it was easy and made her working day more productive. She had more energy, better focus, and lost 4kgs of weight in 3 weeks which was more than she had lost in any previous program.
Although she wasn’t terribly overweight to start with, she had a stubborn belly she just couldn’t shift, and Vanessa was well on the way to having the flat belly she dreamed of.