The what, the why, the how


This month’s blog covers all things intermittent fasting. As we looked into IF, we tried to dig a little deeper, while also providing you with the overall picture of the benefits it can offer.

First of all, what is intermittent fasting (or IF)? IF is an eating pattern that cycles between periods of fasting and eating - it’s all about when to eat, not what to eat. This could mean fasting first thing in the morning and having a first meal at midday, or fasting in the evenings by not eating anything after 7pm - for example.

As we have evolved, regular meal times have been deeply engrained in our day-to-day structure. Miss a meal and many of us are taught to think that this is disastrous! Research suggests that this is not the case and in fact missing meals in a sensible and well-structured way could actually be a “tool” for optimal health. In this blog, we take the perspective of looking at IF from both a weight-loss and overall health stance.

Our aim is to provide you some foundational knowledge and key resources so you can think about how you can implement IF into your weekly health plan. IF isn't necessarily for everyone, and should be used in a calculated, mindful way in order to achieve successful results.

Thanks in advance for reading and looking forward to seeing you all in the studio very soon!

For those of you who don’t already train with us and are interested in taking up some next-level personal training, please contact us at

Healthy Regards,

The Soho Fitness Lab Team

Health benefits of intermittent fasting and caloric restriction on the cardiovascular and cerebrovascular systems

Weight loss is not the only benefit of IF. Research has shown that intermittent fasting (and the resulting caloric restriction, or CR) leads to an improvement in the overall health of overweight humans, and studies conducted on rodents and monkeys have proved links between IF and increased longevity and resistance to age-related diseases.

Cellular and molecular effects of IF/CR on the cardiovascular system and the brain are similar to those of regular physical exercise, suggesting some crossover in mechanisms. IF and CR can lead to a reduction in blood pressure and increased insulin sensitivity (risk factors for coronary artery disease and stroke), therefore improving cardiovascular and brain function.

How to do intermittent fasting

There are 6 popular methods of Intermittent Fasting

1. The 16/8 method - Also known as the Leangains Protocol, this consists of fasting for 16 hours each day and restricting your "eating window" to 8 hours in which you can fit 2-3 meals. An example of this might be eating your last meal at 8pm and then not eating again until 12 noon the next day. You can drink water, black coffee or herbal teas during your fast, as these do not add to your calorie balance.

2. The 5:2 diet - Consists of eating 500-600 calories for 2 days of the week and eating normally for the other 5 days.

3. Eat-stop-eat - This method requires that you do a 24 hour fast once or twice every week. An example (and the easiest way to do it) is to eat dinner then fast until dinner the next day.. It can also be done from breakfast to breakfast or from lunch to lunch. Again, water, coffee and herbal teas are fine to consume during the fasted period.

4. Alternate day fasting - Consists of fasting every other day. There are two ways of approaching the fasted period: 1) eating only 500-600 calories OR 2) fully fasting for 24 hours.

5. The warrior diet - With this approach, you eat small amounts of raw fruits and vegetables during the day and eating a big meal at night. This diet emphasises food choices that are similar to a Paleo diet (whole, unprocessed foods that resemble what they looked like in nature)

6. Spontaneous meal skipping - There is no structured plan here, you can simply skip meals from time to time, when you don't feel hungry.


Cells and Hormones

> Human Growth Hormone increases (up to 5 times) benefiting both fat loss and muscle gain.

> Insulin sensitivity improves and levels of insulin drop, making stored fat more accessible for your body to burn during workouts.

> Stimulates cell repair. During the fasted period, cells initiate cellular repair processes including autophagy, where the cells digest and remove any build up of old and dysfunctional proteins.

> Genes related to longevity and disease protection change in function.

> Noradrenaline is increased, which can benefit your training as it’s a fat-burning hormone

> Short term fasting can increase the body's metabolic rate by up to 14%

Overall Health

> Studies have shown that when losing weight, intermittent fasting helps to ensure less muscle loss compared to simple continued calorie restriction. Plus, it’s particularly helpful when it comes to shifting stubborn belly weight.

> By reducing insulin resistance, IF helps to provide protection against type 2 diabetes

> Reduces inflammation, a major contributing factor in a range of health conditions

> Promotes heart health by reducing levels of LDL (‘bad cholesterol’)

> Reduced the risk of cancer

> Enhances brain health by increasing levels of the brain hormone BDNF and may aid the growth of new nerve cells, helping to protect against Alzheimer’s disease.

> May have anti-ageing benefits (studies show rats live 36-83% longer!)

Benefits for digestion

Keeping things simple, by taking a slightly longer break between two meals, for example between dinner and breakfast the following day, or dinner and lunch the following day, your digestive system has the chance to empty and your body can focus on other important bodily functions. This can provide a sense of relief from digestive distress symptoms, such as bloating, constipation and heartburn.

When fasting, various changes happen in the body, including:

  1. Lower insulin in the blood,
  2. Increases in blood levels of growth hormone,
  3. Cellular repair,
  4. Increased metabolic rate (the rate at which we burn calories).
  5. Relief from some digestive distress symptoms.

Benefits for the brain

Studies conducted so far have found that mice maintained on an IF diet showed a slower age-related deterioration of neurons, a lower incidence of neuro-degenerative diseases and increased synaptical and electrical activity in the brain, compared to normal mice (diet doctor). This suggests a potential benefit of intermittent fasting in terms of cellular repair and regeneration.

In humans, it seems that both IF and caloric restriction are connected to improved memory and mental sharpness. Remember that sleepy feeling after finishing a big meal, kind of the opposite of mental acuity, right? Whereas, think of the last time you were really hungry, there were probably moments of fatigued, but also moments of being perfectly sharp and alert. This will also increase and improve with time, as the body adjusts to fasting.

Various studies have shown that mammals mental activity increases when hungry and decreases with satiation, and lower bodyweight or BMI have been linked to better memory and sustained mental abilities through time.

IF, caloric restriction and exercise all contribute to reducing caloric intake, weightloss and decreasing insulin levels.

When to avoid

> If you’re underweight or have a history of eating disorders

> There is evidence to say it’s not as beneficial for women - some studies show that although it improves insulin sensitivity for men, it actually worsens it for women. It can also lead to cessation of menstruation in women. If you’re a woman who would like to try intermittent fasting, it is recommended to ease into it gently and stop immediately if arenorrhea (absence of period) occurs.

> If you have fertility issues, are pregnant or breastfeeding, it is not recommended.

Safety and Side effects

People report feeling more alert and energetic when fasting, however there can be side effects for the first few days while your body adjusts.

> Hunger

> Weakness

> Brain fog


Ultimately, IF can be used as a tool for reducing how much you eat in a day and for giving your digestive system a chance to rest and reboot. There are other suggested benefits such as mental acuity, long term brain health, improved cell repair and regeneration, and better overall weight and health. To learn more, please speak to one of our personal trainers. We are more than happy to chat!

For those of you who don’t train with us and are interested in taking up some next-level personal training please contact us at

Thanks so much for reading!

The Soho Fitness Lab Team


Published on 27th May 19