CLAIM:
The one-meal-a-day (OMAD) diet is unsafe, impractical, and not backed by strong scientific evidence for sustainable weight loss. It can lead to nutrient deficiencies, low energy levels, hypoglycaemia, especially in people with diabetes, and may increase long-term cardiovascular and overall mortality risk, while weight change ultimately depends on total calorie intake rather than meal frequency.
FACT:
The OMAD diet is an extreme form of intermittent fasting with limited long-term evidence to support its safety or superiority for weight loss. While it may benefit a small, carefully selected group under medical and nutritional supervision, it carries risks such as nutrient deficiencies, blood sugar fluctuations and disordered eating. Experts stress that it is not suitable for everyone, especially people with diabetes, and should not be followed without professional guidance.
You are on a love-hate relationship with your diet for weight loss, and you are bombarded with suggestions online and offline, from detox drinks to extreme fasting routines. One such trend doing the rounds is the one-meal-a-day (OMAD) diet.
In a viral Instagram reel posted by dietician Bhawesh Gupta, a video of fitness influencer Sonia Hooda appears, where she is seen explaining and promoting the OMAD diet. Sonia Hooda claims that the diet is widely followed by celebrities for fitness and weight loss.
In the video shown within Bhawesh’s reel, Sonia says, “Big celebrities follow this diet plan to keep themselves fit or if someone wants to lose weight.” She goes on to explain that OMAD means consuming all meals of the day in just one single meal.
Reacting to this, Bhawesh Gupta responds with a sharp critique. “Well, my three roast videos had some effect on Sonia ji. At least she realised that no one takes her seriously,” he says, calling out the repeated use of celebrity references to promote extreme diet practices.
The video reappears where Sonia continues explaining the diet, “This diet plan is called OMAD diet, which means one meal a day. You have to take your meals for the whole day in just one meal.” Bhawesh counters the claim strongly.“Look, if there is any nonsense after Sonia ji’s content, then it is this OMAD diet,” he says.
According to him, OMAD is neither practical nor suitable for a normal individual. “And if you follow it somehow, you may have to face symptoms like nausea, dizziness, low energy and constipation,” he adds.
He further points to the risk of nutrient deficiencies, explaining that meeting daily requirements of carbohydrates, proteins, fats, vitamins and minerals through a single meal is nearly impossible.
When Sonia claims benefits such as improved insulin sensitivity, fat loss, weight loss and better skin, Bhawesh dismisses these assertions. “All the benefits she’s talking about, the reality is completely opposite,” he says.
For people with diabetes, he warns, OMAD can increase the risk of hypoglycaemia, and in severe cases may even lead to hospitalisation.
Referring to research findings, Bhawesh adds that participants consuming one meal a day have shown an increased risk of cardiovascular disease and overall all-cause mortality. On weight loss, he clarifies, “It depends on your total calorie intake. If you consume more calories than required in that one meal, you can actually gain weight instead of losing it.”
The reel has generated significant engagement and has sparked fresh debate around whether one meal a day is safe or not.
What is the one-meal-a-day (OMAD) diet?
The one-meal-a-day (OMAD) diet is a weight-loss approach in which a person consumes all their daily calories in a single meal and avoids anything containing calories for the rest of the day. It is considered an extreme form of intermittent fasting.
OMAD typically follows a 23:1 fasting pattern, meaning a person fasts for 23 hours and eats within a one-hour window. During the fasting period, no caloric foods or beverages are consumed, though water and non-caloric drinks are usually allowed.
Most people who follow OMAD choose to eat their only meal in the evening and then fast until the same time the next day. However, some research suggests that meal timing may matter. A 2019 study indicated that skipping breakfast could impair glucose control later in the day and may increase the risk of type 2 diabetes, particularly in susceptible individuals.
At the same time, a 2019 meta-analysis of 13 studies found that people who skipped breakfast tended to consume slightly fewer calories overall than those who ate breakfast. While the authors noted that breakfast skipping alone is unlikely to be an effective long-term weight-loss strategy, they also emphasised that more research is needed to fully understand its metabolic effects.
There are multiple variations of the OMAD diet. Some versions encourage eating balanced, nutrient-dense foods during a single meal, while others place no restrictions on food choice, allowing people to eat whatever they want within the eating window.
Is the OMAD diet safe?
People who follow the one-meal-a-day (OMAD) diet often believe it offers several advantages, including rapid weight loss, freedom from calorie counting, and no restriction on specific foods. However, scientific evidence supporting these claims remains limited.
Some small studies suggest potential short-term effects. For instance, a 2022 study found that consuming a single meal in the evening may support modest weight loss and increase fat oxidation during exercise. Fat oxidation refers to the body’s ability to break down fat for energy. However, the study involved a small number of participants, limiting how widely its findings can be applied. Researchers noted that larger and longer-term studies are needed.
Broader evidence on intermittent fasting, under which OMAD falls, presents mixed results. A 2022 meta-analysis reported that intermittent fasting, particularly alternate-day fasting, may be as effective for weight loss as continuous calorie restriction. However, the authors emphasised that further research is required.
In contrast, a 2023 systematic review found little evidence to suggest that intermittent fasting is superior to traditional calorie-restricted diets when it comes to weight loss or improving metabolic risk markers for diabetes and cardiovascular disease. This suggests that fasting-based approaches do not offer clear advantages over less restrictive dietary methods.
There is very limited research specifically examining the effects of fasting for 23 hours per day, as practised in OMAD. Because it is an extreme form of dietary restriction, experts caution that it may carry potential risks. On a day-to-day basis, people following OMAD may experience intense hunger, fatigue due to irregular energy intake, shakiness or weakness linked to falling blood sugar levels, irritability, and difficulty concentrating.
Eating just once a day may also make it hard for some individuals to consume enough nutrients, as they may feel full quickly. Conversely, restricting intake so severely may increase the risk of overeating during the single meal. A 2023 review noted that highly restrictive diets can cause psychological distress and may contribute to disordered eating behaviours, including binge eating.
Certain groups face additional risks. People with conditions such as type 1 diabetes, hypoglycaemia, or other metabolic disorders often need to eat at regular intervals to maintain stable blood sugar levels and may find OMAD unsafe without medical supervision.
Evidence from longer-term fasting studies also raises concerns. In a study published in JAMA Network, 100 participants followed an alternate-day fasting pattern for one year, consuming 25 pc of their energy needs on fasting days and 125% on non-fasting days. Although this was not an OMAD protocol, participants experienced an increase in low-density lipoprotein (LDL), or “bad”, cholesterol — a known risk factor for heart disease and stroke. Importantly, they did not lose more weight than participants who followed a daily calorie-restricted diet.
What experts recommend?
Dr Rajiv Kovil, Head of Diabetology and Weight Loss Expert at Zandra Healthcare, explained, “There is no doubt that OMAD can offer benefits, but it should not be done without supervision,” he said. “You may actually miss out on essential nutrition if the diet is not personalised and nutritionally adequate. Under proper guidance from a qualified nutritionist, it can be very effective.”
Dr Kovil highlighted the historical perspective, noting that our ancestors often ate one meal a day or had long fasting periods, suggesting that structured fasting has roots in traditional eating patterns. “Eating early at sunrise and finishing dinner before sunset has its advantages,” he said, “but OMAD specifically can activate autophagy – a recycling process where damaged proteins and organs are repaired.”
He also pointed out metabolic benefits, “Extended fasting periods improve insulin sensitivity by giving pancreatic beta cells and insulin signalling pathways a rest. Many Indians, despite eating two or three meals a day, remain in a post-absorptive state for only 16–18 hours because of a high-carb, high-fat diet. Their insulin pathways don’t get rest, which contributes to hyperinsulinemia, a key driver of obesity, diabetes, and metabolic syndrome.”
However, Dr Kovil cautioned that OMAD is not suitable for everyone, particularly people with diabetes. “We do not advise OMAD for people with diabetes unless they are on medications that don’t cause hypoglycemia,” he said. “But for pre-diabetics, those seeking weight control, and individuals without gallstones or constipation, OMAD can be effective under proper supervision.”
He also mentioned gut health benefits, stating that long fasting periods allow the digestive system to rest, reducing bloating, reflux, and indigestion. “I have many patients on OMAD,” Dr Kovil added. “Those who are pre-diabetic or looking for weight control have seen good results. The key is proper guidance, which makes adherence easier and the diet safer.”
This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS.