Is Fasting Good or Bad For Your Body? Find Out

Ever wondered how all that fasting during festivals affects your body? FIT explains.

Chew On This
4 min read

Indians need an excuse to fast.

Some do it in the name of tradition and religion, others do it for politics and in protest. Some just do it to lose weight.

Most popular religions call for different types of fasts as a ritual of spiritual purification.


Under some fasts, devotees refrain from eating for close to 12 hours at a stretch. Under others, devotees keep away from heavy meals, choosing to munch on fruits and other special items during the day.

Religious fasts like Navratri and Ramzan have been going on for centuries.
Religious fasts like Navratri and Ramzan have been going on for centuries.
(Photo: iStock)

But have you ever stopped to think about the effects fasting has on your body? Is it healthy?

If you are in good health and you fast for a day or two, you are going to be alright. But fasting can be dangerous if you have pre-existing medical conditions.

Remember This When You Break That Fast

There’s just one tiny problem with modern day fasting. It’s about the amount that is consumed when the fast is broken.

Take Navratri, for example. Traditionally, you'd be eating healthy food – the stuff of dieticians’ dreams. But let’s be realistic. You’re more likely to end a fast by eating deep-fried snacks and a heavy, greasy meal. And that's a problem!


What Happens if You Fast?

Food is basically your body’s energy supply – carbs, fats, protein.

When you eat, your insulin levels rise, telling your body to take the glucose from your food and use it as energy. Also, your body isn’t the type to let the leftovers go waste. So, the excess is stored as glycogen in your liver.

Long story short, when we don’t eat, this energy has to come from somewhere else.

Is Fasting Good or Bad For Your Body? Find Out
(GIF Courtesy:

Six to 24 hours after your last meal, your insulin levels begin to drop and the stored glycogen gets called in to provide energy.

Day 1: Your liver starts using amino acids to make glucose.

Day 2: When your entire stock of carb has been used up to provide glucose, emergency services kick in and the body starts breaking down fats through a process called lipolysis.

The fatty acids in the liver begin to break down into ketones – which are then used as energy.

Day 4: About 75 percent of the energy for your brain comes from these ketones.

Quick fun fact. The ‘keto diet’ or ‘low-carb’ diet is based on relying on ketones for energy instead of carbohydrates.

Next, the body starts breaking down proteins.

Fasting For Weight Loss

Fasting is not a healthy tool for weight loss. NOT AT ALL.

It may seem like a quick way to lose some kilos, but most of it is really a loss of fluids or “water weight”. Shedding of actual fat? Much less.

Fasting is not a healthy weight loss tool.
Fasting is not a healthy weight loss tool.
(Photo: iStock)

Fasting for weight loss is a self-defeating exercise. All the weight you lose will come back pretty quickly, when you start eating normally or overeat.

Fasting slows down your metabolism as well. So, when you’re eating again, it makes it easier to gain weight. How's that for a double whammy?


Fasting to ‘Detox’

Does fasting for detox really work? Well, scientific evidence suggest not. However, doctors are split over the issue.

The liver is your body’s natural detox centre. In addition, colon, skin, kidney and lungs help flush out toxins.

Some doctors argue that the removal of toxins is not affected by whether you’re having your meals or missing them, since your body is pretty good at doing that by itself.

However, other doctors beg to differ, and claim that fasting is an effective detox method because it burns fat – which is where most toxins are stored.

There, that’s the long and short and the thick and thin of fasting.

Still thinking of skipping a meal or two? Well, now you at least have some food for thought to chew on!

Video Editor: Puneet Bhatia

Cameraperson: Abhay Sharma

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