While humans have been fasting for centuries due to food scarcity, we’re now doing it by choice.  But can changing when you eat rather than what you eat really help you lose fat and build a better physique? 

Intermittent fasting is a concept that is taking the fitness and nutrition world by storm. It isn’t a diet, but rather a pattern of eating that involves alternating between periods of fasting and eating. The main goal of intermittent fasting is to force your body past the absorptive state and into a prolonged fasted state so that it uses stored fat as energy.

Why fast?

With intermittent fasting, you force your body to regularly enter a fasted state which, according to some researchers, could come with body composition benefits including fat loss while preserving muscle mass. Additionally, intermittent fasting makes it more difficult to overeat throughout the day as your eating window is smaller, making it easier to maintain a lower body fat percentage.

Intermittent fasting has also been shown to reduce inflammation, blood pressure, and “bad” cholesterol, as well as increase insulin sensitivity, ultimately reducing the risk of type 2 diabetes.

Intermittent fasting methods

Leangains Method: The Leangains method is the most popular IF method. With Leangains, you alternate between 16-hour fasted periods and 8-hour feeding periods. You can schedule the meals whichever way works best for you. If you're not a morning person and you have to force down your breakfast, start eating at 12 noon and finish at 8pm. If you need breakfast every day, adjust accordingly.

Your diet should be high in protein, and you should follow the basic principles of nutrient timing (eating the majority of your carbs post-workout, etc.). You should also include fasted training.

Alternate Day Fasting: Alternate Day Fasting is pretty simple; on this plan you eat every other day. 

On “eating” days, you eat within a 12-hour window. For example, you could eat from 7 am to 7 pm on Monday and then fast until 7am on Wednesday. Some people follow a modified approach where they interpret fasted days as restricted days where they consume fewer than 600 calories, but don’t actually fast. During feeding days, you can essentially eat what you want without limit.

See also: Ask A Trainer: How Do I Stay Fit While Travelling?

Meal Skipping: The free-form, hippie version of IF. Proponents of this method try to mimic the eating patterns of our evolutionary ancestors who, in the hunting and gathering days, didn’t have regular access to food. 

With this method, you’re encouraged to randomly skip meals a few times a week. Food choices should also be close to what our ancestors ate, which is essentially a Paleo diet. 

Eat-Stop-Eat: In this intermittent fasting plan, developed by Brad Pilon, you fast for 24-hour periods up to two times per week (never on consecutive days). Food choices aren’t restricted on eating days, as he theorises that fasting even once per week will put you on a weekly 10% caloric deficit. However, you are urged to eat a normal-sized meal when coming off a fast (so don’t shovel food into your mouth until you feel nauseous), and to generally eat within reason. 

Warrior Diet: The warrior diet involves 20-hour underfeeding periods followed by four-hour periods of overfeeding (a binge eater’s dream), making it suitable only for hardcore intermittent fasters. During the underfeeding periods, you can still consume fruits, vegetables, and small amounts of protein. Anything substantial must be reserved for your overfeeding period.

Is it for you? 

It's all about context for the clients we work with at Ultimate Performance. It may be useful for a handful of clients but it always depends on the individual and their goals. One thing we try to do is shift clients from grazing around the clock to using a 12- or 10-hour eating window, which can be beneficial in keeping your appetite in check.

So will intermittent fasting help you lose body fat? The current research is not completely conclusive, so the best way to find out is to give it a go. Because the mental component of dieting is so instrumental to fat loss success, your mindset and behavioural patterns will play a huge part in which method works for you.

When starting an intermittent fast, it's recommended that you maintain your regular calorie intake as the introduction of fasting alone may be enough to induce fat loss.

Beau Elvis Radclyffe-Thomas is a certified personal trainer with Ultimate Performance Hong Kong. Find out more at upfitness.com.hk

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