Without depriving one of food, the fasting-mimicking diet (FMD) allows for getting the benefits of fasting with structured calorie intake. Unlike complete fasting, FMD entails having low-calorie, plant-based meals over a defined period (typically five days), thus promoting metabolic and cellular changes similar to prolonged fasting,” said clinical dietitian Garima Goyal.
In simple words, this dietary strategy aims to mimic the advantages of fasting without entirely limiting food consumption. “It focuses on limiting calorie intake for a brief period to activate the body’s fasting processes while still supplying necessary nutrients. The goals of this five-day diet are to support weight loss, enhance metabolic health, and foster cellular regeneration,” said Dt. Vaishali Verma, consultant- nutrition and dietetics, Manipal Hospital Dwarka, New Delhi.
How does FMD work?
As a structured, low-calorie plan, on Day 1, individuals consume about 1,100 calories, with a macronutrient breakdown of approximately 43 per cent carbohydrates, 11 per cent protein, and 56 per cent fats. “This higher calorie intake is meant to ease the body into the diet. On days 2-5, the caloric intake is reduced to around 700 calories per day, with a macronutrient composition of mostly fats and minimal protein and carbohydrates,” said Verma.
FMD operates by reducing calorie intake in a way that tricks the body into a fasting state while still providing essential nutrients. It typically involves:
*Day 1: Caloric intake is about 50-60 per cent of normal (~1000-1100 kcal).
*Days 2-5: Caloric intake drops further to 35-40 per cent (~700-800 kcal per day).
Macronutrient composition:
*High in healthy fats (mainly plant-based sources).
*Moderate carbohydrates (10-50 per cent).
*Low protein intake (2-5 per cent) to activate fasting-related pathways.
This controlled caloric deficit helps the body switch to fat metabolism, reduce inflammation, and activate cellular repair mechanisms like autophagy (the body’s process of clearing out damaged cells), noted Goyal.
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Created by Dr Valter Longo’s dietary program, it requires participants to eat meals deficient in calories, proteins, and sugars while abundant in healthy fats for five days. “The diet configuration aims to activate fasting-like advantages including weight reduction and metabolic health enhancement alongside inflammation decrease and cellular renewal without total food deprivation,” said Kanikka Malhotra, consultant dietician and certified diabetes educator.
Typically plant-based, the meals are made with low-protein items low-carbohydrate options, and healthy fats (like avocado and olive oil). “Similar to what happens during fasting, the diet’s mechanism of action involves reducing protein and glucose levels, which sets off the body’s internal processes of autophagy (cellular cleansing and repair) and metabolic reset,” said Verma.
Benefits of FMD
Weight loss: While maintaining muscular mass, the FMD is intended to reduce fat. It promotes the body to use fat as fuel, which helps people lose weight, particularly those who are classified as overweight or obese, said Verma.
Cellular regeneration: The FMD supports the body’s healing and cell regeneration by encouraging autophagy. Old or damaged cells are removed by this process.
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Here’s what you need to note (Photo: Getty Images/Thinkstock)
Enhanced metabolic health: Studies indicate that the FMD may decrease inflammation and increase insulin sensitivity, which both enhance metabolic health and may lessen the risk of long-term conditions, including heart disease and type 2 diabetes, Verma said.
Longevity: According to long-term research on calorie restriction and fasting, occasional fasting may increase longevity by lowering the risk of ageing-related illnesses, enhancing cardiovascular health, and promoting brain function, said Verma.
How is FMD different from a balanced diet?
However, FMD is not meant to replace a balanced diet. It is to be cycled periodically to gain specific metabolic benefits, stressed Goyal.
Things to note
Verma cautioned that FMD is not appropriate for everyone, despite its possible advantages. “People with underlying health concerns, such as eating disorders, pregnancy, breastfeeding, or chronic illnesses, should avoid it unless under the supervision of a healthcare professional,” said Verma.
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Furthermore, if not followed correctly, there is a chance of nutrient inadequacies because of its low protein and calorie content.
The body may experience fatigue, hunger, and irritation during the initial days as it adapts to the lower calorie intake. “Although the FMD may cause short-term weight loss, it’s crucial to remember that weight loss may return when the diet is over if healthy habits aren’t maintained. Additionally, because the body is in a low-energy phase during the diet, vigorous physical exertion should be avoided,” said Verma.
Not for everyone: People with diabetes, eating disorders, or certain medical conditions should consult a healthcare professional before attempting FMD, said Goyal.
Not a daily diet: Unlike a balanced diet, FMD is done in cycles (e.g., once a month) rather than every day.
Requires supervision: If used for medical purposes (e.g., metabolic disorders), professional guidance is recommended.
People who have medical conditions or tendencies toward disordered eating need to seek advice from qualified professionals before beginning any new regimen, cautioned Malhotra. “The dietary regimen targets generally healthy people who wish to control their weight and enhance their lifespan,” said Malhotra.
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Experts note that it should be viewed as a periodic intervention rather than a daily lifestyle choice. “For long-term health, a well-balanced diet remains essential,” said Goyal.
DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.