Does Fasting Work?

Does fasting work
Does fasting work?

Also known as the 5:2 diet, the Fast Diet is one of the more recent trends to hit the weight loss market. The name might suggest a quick fix, but in fact it is a way of eating that involves periods of restricted calorie intake combined with eating normally. In this article, we take a look at fasting as a way to lose weight and also find out the thoughts of a wellness professional.

How does the Fast Diet work?

By now, you might well have heard about the Fast Diet. It was back in 2012 that doctor and TV presenter, Michael Moseley, appeared on a BBC Horizon programme talking about how intermittent fasting could improve health and promote steady weight loss. A book authored by Moseley and Mimi Spencer followed in 2013.

Promoted as a life-changing way of eating for weight loss, the basic idea is that for five days a week, you eat normally; on the other two days, you restrict your calorie intake to 500 per day for women and 600 per day for men. You get to choose the days on which you fast, so you can do them consecutively or spread them over the week. The system assumes a calorie intake on a normal day of 2,000 for women and 2,400 for men.

Is it safe to fast to lose weight?

This is an important point to address because there are some people for whom fasting is not recommended. These groups include:

  • Those who have an eating disorder or who are underweight
  • Anyone under the age of 18
  • Pregnant and breastfeeding women
  • Anyone who has an underlying medical condition or is recovering from surgery
  • Diabetics

This is not an exhaustive list, so the best advice is to always check with your doctor before embarking on this or any type of weight loss regime. However, for otherwise healthy adults, this type of eating plan can offer a range of benefits.

Can you lose weight by fasting?

That’s the whole idea! The Fast Diet cuts your calorie intake to a quarter of its normal level on your restricted days. This way, you should lose around 1lb a week. Of course, this is dependant on not going crazy on your five normal days! It also depends on your level of physical activity.

On fasting days, the idea is to stick to high protein and high fibre foods, such as lean meat, fish and vegetables, while avoiding sugary, high-carb, starchy and fatty foods. So, blowing your day’s allowance on a slice of pizza and a chocolate bar is not recommended!

While 500 (or 600) calories a day is deliberately restrictive, it is possible to enjoy a range of foods and even snacks. Options include: two boiled or scrambled eggs with wholemeal bread, plain yoghurt with fruit, green salad with chicken breast, grilled fish and vegetables, and unsalted nuts. The 5:2 diet has been such a phenomenon that there are lots of online resources out there to help you use up those 500 calories in the healthiest and tastiest way!

The final point to make is that calorie counting on your restricted days is crucial. Pay attention to portion sizes and keep track of calories (and exercise) with a free app, such as MyFitnessPal.

What are the health benefits of fasting?

In addition to weight loss, there have been studies that have shown an intermittent fasting diet can have other health benefits, such as helping to lower blood pressure and cholesterol. Again, always get advice from your doctor to make sure what you’re doing is safe.

Can you drink water when you fast?

Yes, and it’s important to stay well-hydrated. You are free to drink anything you like, as long as it is no or low-calorie. So, tea and coffee are fine. Don’t forget that milk adds extra calories, so stick to a splash or cut it out altogether on those days. It’s best to avoid alcohol on fasting days.

Key points for intermittent calorie restriction:

  • Keep busy when fasting to take your mind off food!
  • You can exercise on fasting days (unless otherwise advised by your doctor) but avoid heavy-duty endurance training
  • Plain or sparkling water or green tea can satiate those hunger pangs
  • Protein can also fill you up and curb carbohydrate cravings
  • You don’t have to count calories on your non-fast days (but don’t overdo it!)
  • Record your weight and waist size before embarking on the programme and log your progress for motivation
  • Switch to a maintenance mode of 6:1 (six normal days and one fasting day a week) once your target weight has been achieved
  • Consider a break at a health spa to give your weight loss regime a boost or to reward yourself for achieving your goals

Sue Davis, resident naturopath at Lifehouse Spa in Essex, shares her thoughts on intermittent fasting…

“I first came across the concept of restricting calories for health when I chose ‘Human Ageing’ as an elective subject for my Human Health Science degree. The focus was very much on telomeres. These are protective caps at the end of chromosomes which shorten with age and act as significant biomarkers of cellular ageing. Short telomeres have been linked to a whole host of health problems, ranging from diabetes, heart disease and dementia to premature death. I learnt that calorie restriction was one way to extend the length of telomeres and ultimately the lifespan of a human.

“We are designed to fast, and in many cultures and religions, fasting forms a regular and significant part of people’s lives. As man evolved, there would have been periods of gluttony interspersed with very little sustenance being available. Man survived these periods of feast and famine and now, through further scientific research, calorie restrictive regimes have become popularised as the new non-diet and way of life.

“Calorie restriction is nothing new and has been known about for many years. Anti-ageing specialists, especially in Europe, prescribe ‘dinner cancellation’ twice a week. This involves missing dinner on two non-consecutive days of the week. Since the bulk of calories often features in the evening meal, this serves to reduce the calories in a day quite significantly. This tactic or intermittent calorie restriction, whereby a normal daily calorie intake is reduced to 25%, triggers certain mechanisms in the body to switch from continual growth mode to repair mode. Thus, the life span of an individual cell is programmed to live for longer. The other important benefit of calorie restriction is the reduction of Insulin-Like Growth Factor 1 (IGF-1). Good supplies are needed to create a full-size adult, but once a human has stopped growing, it would appear high levels of IGF-1 can be responsible for accelerated ageing and even cancer.”

Finally, Sue discusses her personal experiences with the Fast Diet:

“I’ve found that hunger comes in waves and you can feel a little light-headed when you first start out. I start the day with a hemp protein and super greens smoothie and then drink green tea and water throughout the day until around 5.00pm when I have dinner. That’s it until bedtime. There have been weight fluctuations, but overall the weight loss holds, especially if you commit to an exercise plan. I’ve been doing interval training type classes three times per week; four is reported to give faster results. In addition, my sleep has been better and my thought processes sharper. Once I reach my ideal weight, I will then switch to a 6:1 maintenance mode to continue reaping the many health benefits associated with calorie restriction.”

For more information about the Fast Diet, check out and to find out more about health spa breaks, give us a call today!

About the author

'Since 1989, SpaSeekers has been helping customers find their perfect spa experience. All packages come with a best price guarantee at over 500 of the UK's leading spas.'

Have your say

comments powered by Disqus

Share this post