The concept of fasting in India isn't new and has been practised for centuries. It is one of the preferred ways to rid the body of all toxins and now, more and more millennials and young adults are joining the league looking for a fit lifestyle, health experts said on Thursday.

The most famous technique of losing weight among the Indian millennial and young adults is intermittent fasting, embraced in style by Twitter CEO Jack Dorsey.

Intermittent fasting is an eating pattern that cycles between periods of fasting and eating. It doesn't specify which foods you should eat but rather when you should eat them.

It generally falls into two categories -- daily time-restricted feeding, which narrows eating times to 6-8 hours per day, and so-called 5:2 intermittent fasting, in which people limit themselves to one moderate-sized meal two days each week.

"In India, it's a normal religious belief on doing fasting. People do fast for their God and goddesses and follow some diet regime. And nowadays few types of diets are coming like intermittent fasting which is based on proven science and facts and some trials," Namita Nadar, Head Nutritionist, Fortis Hospital, Noida told us.

Several studies have shown that intermittent fasting may improve blood sugar regulation, increase resistance to stress and suppress inflammation.

"Intermittent fasting could be part of a healthy lifestyle," said Mark Mattson, Neuroscientist at Johns Hopkins Medicine in the US, who has studied the health impact of intermittent fasting for 25 years, and adopted it himself about 20 years ago.

"Evidence is also mounting that intermittent fasting can modify risk factors associated with obesity and diabetes," Mattson added in a paper published in The New England Journal of Medicine.

According to experts, when we fast, there are several things that happen in our body on the cellular and molecular level.

Like, our body adjusts hormone levels to make stored body fat more accessible and our cells also initiate important repair processes and change the expression of genes. So, they suggest that intermittent fasting should be done under proper guidance.

"Intermittent fasting helps in weight loss, it lowers blood sugar, blood pressure and cholesterol too. But, at the same time, intermittent fasting needs to be followed under the supervision of a nutritionist," suggests Ritika Samaddar, Chief Clinical Nutritionist, Regional Head, Dept of Clinical Nutrition and Dietetics, Max Healthcare, Delhi.

Intermittent fasting shows an effective result and can easily fit into anybody's lifestyle.

It involves eating only during an eight-hour window and fasting for the remaining 16 hours.

"One can repeat this cycle as frequently as they would like to. One can start with once or twice per week to every day, depending on the nutritional needs and personal preferences," the experts informed.

However, there are some side effects too like nausea, headaches, insomnia, hunger and fatigue.

"People should not try fasting if suffering from eating disorders like bulimia, binge eating disorder, pregnancy, lactation, type 1 diabetes, etc," said Dr. Vasundhara Singh from the Department of Dietetics, AIIMS, New Delhi.

One should be cautious and should keep following points while practicing fasting, like not eating too much too soon, not eating fewer calories (don't go below 1200 Kcal), being sedentary and avoid aerated drinks and sodas.