EVIDENCE BASED NUTRITION

Written by Henry Lau 
Qualified Nutritionist and ISAK Accredited Anthropometrist

EVIDENCE BASED NUTRITION

Written by Henry Lau 
Qualified Nutritionist and ISAK Accredited Anthropometrist

The Ultimate 2020 Guide To A Fasting Diet

The secret to succeeding on a fasting diet is simple, you choose a certain time to stop eating and a time when you do.

But the problem is, there are many different ways to fast and they don’t all give the same results. In fact, people commonly follow unhealthy fasting protocols that aren’t ideal for weight loss and could potentially be more harmful.

A fasting diet is definitely NOT for everyone, but it may be exactly what you need to live healthier and more energetically.

This article reviews the healthfulness of different types of fasts, the right foods to eat and the best way to follow a fasting diet.

What Is Fasting?

Fasting is an eating pattern where you restrict your food intake for a certain time period, then alternate with periods of feeding.

Fasting can be divided into two categories; chronic energy restriction (CER) and intermittent energy restriction (IER) or commonly known as intermittent fasting (IF).

In addition, intermittent fasting can be further divided into three sub categories: alternate day fasting (ADF), whole day fasting (WDF), and time restricted feeding (TRF) (1).

Summary:

Fasting is an eating pattern where you have periods of food restriction alternated with periods of eating. These are divided into chronic and intermittent energy restrictions.

Does Fasting Work For Weight Loss?

Like most diets, fasting works through restricting food intake to create a shortfall of calories, which leads to weight loss overtime.

Whether you choose to fast during different times of the day or different days of the week, and then followed by a feeding period, the overall net calorie deficit is what causes weight loss.

In a recent scientific review comparing different types of fasting, majority of the participants who were intermittently fasting had a calorie intake ranging from 400-600 kcals on fasting days or equivalent to approximately 25% of their energy needs. On non-fasting days, they consumed 1600-1800 kcals or 125% of energy requirements.

Whereas, participants who fasted continuously reduced their calories between 25% to 33%.

The review also found, that over a 12 to 14 week period, individuals who were intermittently fasting lost 5.2% to 12.9% of their original weight. In contrast, individuals who continuously fasted lost 4.3% to 12.1% of their original weight.

This scientific review pooled together the results from 11 different studies and demonstrates that fasting, whether it’s intermittent or continuous, is a viable option for weight loss.

Interestingly, the findings show no difference in weight loss between both of the fasting protocols and are equally effective in reducing weight.

It is also important to consider that a diet only works if you can stick to it long enough to see significant weight loss. Unfortunately, fasting appears to be a difficult method for a lot of the participants to adhere to.

In the same review, it was found that 102 out of 630 participants dropped out before completing the program. Adherence to the diet also ranged somewhere between 64% to 93%.

One explanation could possibly be due to the many adverse effects that were reported including: lack of energy, headaches, feeling cold, constipation, bad breath, lack of concentration, hunger and bad breath.

Although fasting is valid method for weight loss, there is a lack of evidence supporting long term success and adherence appears to be an issue for many.

Summary:

Fasting works through weight loss and all different types of fasts give the same result if you match the calories.

Different types of fasts aren’t equally adherable.

How To Fast: Chronic Energy Restriction

Chronic energy restriction is when you consume less than what you to create an energy shortfall.

There are no set time periods of when you can eat or cannot eat.

It involves eating a fixed amount of calories across a day (or week) and can be consumed at any time.

Summary:

Chronic energy restriction involves eating less across a day or a week to create an energy shortfall.

There are no rules around the timing of food.

How To Fast: Intermittent fasting - Alternate day.

The most researched intermittent fasting protocol to date is alternate day fasting and it typically involves 24 hours of fasting alternated with 24 hours of feeding.

The most common way to follow this protocol is to consume 25% of your daily energy intake, typically in the form of a single meal at lunch time.

The idea is that the amount you consume on your feeding day does not offset the calorie shortfall on the fasting day and therefore, total weight and fat loss occurs.

This is then alternated with a 24 hour feeding period where you get to eat as much as you like (2).

Surprisingly, this has been shown to preserve muscle very well (3, 4, 5).

Futhermore, dropping the food intake on the fasting day below 25% does not result in more weight loss.

In fact, researchers have found that dropping food intake on fasting days to zero resulted in the same weight lost (6) and had lead to greater muscle loss, which is a main predictor of future weight regain (7, 8, 9).

Summary:

Alternate day fasting is a type of intermittent fast.

The most common way is to consume a quarter or your normal food in one at lunch time. This is alternated with a day where you get to eat as much as you like.

How To Fast: Intermittent fasting - Whole Day (5/2).

In terms of weight loss, the most consistent intermittent fasting protocol to date is whole day fasting (WDF) and it typically involves one or two 24 hour fasting days and maintenance on the remaining days.

The most common way to follow this protocol is to consume zero food on your fasting days, although for some protocols it’s up 25% of your daily energy intake, and maintenance calories (the amount of calories required for your weight to remain stable) on the remaining days.

When compared to a chronic energy restriction (also know as a daily energy restriction), one study saw no difference in body weight or body fat reduction when the weekly calories was equated over a 6 month period (10).

However, when the researchers followed up with a second study, they tested a variant of the protocol that resulted in greater fat loss after 3 months.

They found that participants who followed an intermittent fast two times a week (either consuming 650 calories per day OR unlimited protein/fat) had lost more weight compared to individuals who cut their calories by 1435 across 1 week (e.g. 250 calories per day).

However, please keep in mind that the fasting groups only lost 0.8kgs more than the non-fasting group across 6 months and had a much larger calorie deficit (11).

Summary:

Whole day fasting is a type of intermittent fast.

The diet involves consuming no or up to 25% of your normal food once or twice a week. You then consume at maintenance for the remaining days of the week.

How To Fast: Intermittent fasting - Time Restricted Feeding (16/8)

The last of the IF variant is time restricted feeding and it typically involves a fasting period of 16-20 hours and unlimited in the feeding period of 4-8 hours daily.

The most widely studied form of time restricted feeding is Ramadan fasting, which involves a month of complete fasting of both food and fluid.

Similar too the other fasting protocols, the restriction in eating resulted in significant weight loss of both fat and lean body mass (12, 13).

Aside from Ramadan fasting studies, research dedicated to time restricted feeding was rare until a recent trial examined a 20 hour fast with 4 hour feeding protocol (20/4).

They found that individuals, with no limit on type or quantity of food in feeding periods, trained 3 days per week had also lost body weight. Although there was no significant difference between a normal diet and a fasted diet (14).

Summary:

Time restricted feeding is a type of intermittent fast.

Time restricted feeding involves a fasting period (typically 16-20 hours a day) and a feeding period of 4-8 hours daily.

Top 11 Foods To Eat While Fasting

A plant based diet can be very tricky to get right as there are a lot of food groups you should and should not be eating as outlined in The Best Way To Follow A Plant Based Diet: How to start, what to eat, what not to eat.

Here are the top plant based foods you can start eating today:

  • Wholegrain crackers: satiety index of 127
  • Popcorn: satiety index of 154
  • Eggs: satiety index of 150
  • Baked beans: satiety index of 168
  • White Fish: satiety index of 225
  • Porridge: satiety index of 209
  • All-Bran Cereal: satiety index of 151
  • Potatoes: satiety index of 323
  • Brown Pasta: satiety index of 188
  • Apples: satiety index of 197
  • Oranges: satiety index of 202

Avoid These Top 11 Foods While Fasting

A plant based diet can be very tricky to get right as there are a lot of food groups you should and should not be eating as outlined in The Best Way To Follow A Plant Based Diet: How to start, what to eat, what not to eat.

Here are the top plant based foods you can start eating today:

  • White Bread: satiety index of 100
  • Croissant: satiety index of 47
  • Cakes: satiety index of 65
  • Doughnuts: satiety index of 68
  • Chocolate Bars: satiety index of 70
  • Nuts: satiety index of 84
  • Chips: satiety index of 91
  • French Fries: satiety index of 116
  • White Pasta: satiety index of 119
  • Bananas: satiety index of 118
  • Special K / Cornflakes: satiety index of 116

Top 11 Foods To Eat On Non-Fasting (Feed) Days

A plant based diet can be very tricky to get right as there are a lot of food groups you should and should not be eating as outlined in The Best Way To Follow A Plant Based Diet: How to start, what to eat, what not to eat.

Here are the top plant based foods you can start eating today:

  • Fruits: All fruits are fine but have a variety.
  • Vegetables: All vegetables are fine but have a variety.
  • Legumes: These includes chick peas, black beans, soy beans, kidney beans, lentils and tofu.
  • Nuts: All nuts and seeds.
  • Whole Grains: These includes oats, quinoa and brown rice.
  • Dairy Products: These includes milk, cheese and yoghurt but low fat options are recommended.
  • Eggs
  • Beverages: Tea and coffee are fine to drink.
  • Herbs & Spices: All herbs and spices
  • Plant based oils: Including olive, rice bran, flax and rapeseed oil.
  • Fish: Includes white fish and salmon
  • Chicken or Turkey: lean cut, fat trimmed

DISCOVER WHAT FOOD IS RIGHT FOR YOU

A custom built quiz designed to help you find out what foods you should be eating.

Discover What Food Is Right For You With This Simple Quiz

Everyone is different…

… we’re different in height, weight, gender, ethnicity, body shape, size, food preference, in our situation, goals, motivation, time & food cravings.

There is an endless amount of different types of diets and it makes it very difficult to decide what is right for you.

That’s why I developed this simple 30 Second Quiz, designed to help you discover EXACTLY what food is right for you…

… and the best part is, you can get started right here, right now.

Take The Free Quiz Here

Henry Lau – Qualified Nutritionist

How To Discover What Food Is Right For You

Everyone is different…

… we’re different in height, weight, gender, ethnicity, body shape, size, food preference, in our situation, goals, motivation, time & food cravings.

There is an endless amount of different types of diets and it makes it very difficult to decide what is right for you.

That’s why I developed this simple 30 Second Quiz, designed to help you discover EXACTLY what food is right for you…

… and the best part is, you can get started right here, right now.

Take The Free Quiz

[ EVIDENCE BASED ] Discover What Food Is Right For You With This Simple 30 Second Quiz

Henry Lau – Qualified Nutritionist

Discover What Food Is Right For You

Everyone is different…

… we’re different in height, weight, gender, ethnicity, body shape, size, food preference, in our situation, goals, motivation, time & food cravings.

There is an endless amount of different types of diets and it makes it very difficult to decide what is right for you.

That’s why I developed this simple 30 Second Quiz, designed to help you discover EXACTLY what food is right for you…

… and the best part is, you can get started right here, right now.

Take The Free Quiz

[ EVIDENCE BASED ] Discover What Food Is Right For You With This Simple Quiz

Read Next:

The Ultmate 2020 Guide To A Plant Based Diet

The Ultmate 2020 Guide To A Plant Based Diet

Top Plant Based Foods You Should Eat

Top Plant Based Foods You Should Eat

Best Way To Follow A Plant Based Diet: How to start.

Best Way To Follow A Plant Based Diet: How to start.