Kunal Kemmu’s transformation sparks a debate: Is diet really 90% of weight loss?

Kunal Kemmu recently opened up about the physical and mental challenges of transforming his body for film roles. Speaking on Honestly Saying Podcast, the Kalyug actor revealed that it took him nearly a year to lose weight for his upcoming film Vibe, and that weekly 24-hour water fasts became a key part of his fitness routine.Reflecting on the demands of drastic body transformations, Kunal admitted that they involve much more than simply losing weight. “It is very tough,” Kunal said, adding that cutting both fat and muscle mass can trigger mood swings that affect not only actors but also their families.
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.
He also praised fellow actor Randeep Hooda for his physical transformation in Swatantrya Veer Savarkar. “I don’t know if I will be able to do what he did for Savarkar,” the actor said.

Recalling his own experiences, Kunal shared that while he lost weight for Go Goa Gone, he deliberately gained weight for a project with filmmaker duo Raj & DK. “That is the first time I reached 80 kg in my life,” he said.”
He also shared that he lifted heavy weights and consumed a carbohydrate-rich diet to achieve a bulkier physique. “Aur woh 90 per cent diet ka hi game hai (It’s 90 per cent diet only),” he said. For his upcoming film Vibe, Kunal said he needed to look leaner and fitter. “It took me a year to go down from 80 kg to 71 kg-72 kg,” he revealed.
The actor said he experimented with water fasting for the first time during this phase. Already accustomed to practising 16-hour intermittent fasting eating an early dinner and delaying breakfast until after his morning workout, Kunal decided to extend one fast to 24 hours after realising he had already completed 16 hours without food.

He said he completed a 24-hour water fast once a week for six weeks, relying on water whenever he felt hungry. He shared that the most difficult period came between the 18th and 20th hour, while the final stretch became mentally easier as he neared the end of the fast.
“And you hit that second wind of sorts. You get wired. It’s like being on caffeine without being on caffeine,” he said.Story continues below this ad
Kunal described fasting as beneficial for recovery and overall health, saying, “I think fasting is very good for your body, just to heal, recover, and de-age naturally.” In addition to fasting, the actor said he switched to a high-fat, high-protein diet and eliminated grains for four months.
Having struggled with acid reflux for years, Kunal also claimed that removing grains from his diet helped alleviate the condition after other approaches, including Ayurveda, had failed to provide relief. However, he later reintroduced rice into his meals while continuing to avoid lentils, limiting bread, and cutting back on processed foods.
According to the actor, the dietary changes not only supported his weight-loss journey but also improved his energy levels.

Protein intake and resance training
Aditi Prasad Apte, Senior Clinical Nutrition at Aster RV Hospital, Bengaluru, emphasised that fat loss as “90% diet” oversimplifies the process.Story continues below this ad
“Diet really does matter a lot because total calorie intake and nutrient quality largely influence body weight. But if someone wants to lose fat while maintaining muscle, adequate protein intake and resance training are equally important,” she said.
Apte explained that strength training sends the body the signal to preserve muscle while losing fat, while regular physical activity supports long-term weight management. Sleep and recovery are also crucial, as inadequate sleep can disrupt hunger hormones, energy levels and overall recovery.
“Sustainable fat loss is a combination of balanced nutrition, consent exercise, sufficient sleep and recovery rather than attributing success to diet alone,” she added.
Kemmu also revealed that he lost around 8-9 kg over the course of a year. Apte said this is generally considered a gradual and sustainable pace of weight loss.Story continues below this ad
“A lot of health guidance favours slow, steady weight loss over rapid reductions because the results are more likely to last. But the focus shouldn’t just be on kilograms lost. It should also include body composition, strength, energy levels and overall metabolic health,” she said.
Side effects of fasting
While Apte said some healthy adults may tolerate occasional fasting, she stressed that it is “not for everyone and often not necessary.” She shared that long fasting periods can lead to headaches, dizziness, fatigue, irritability and difficulty concentrating. Repeated fasting may also make it harder to meet daily nutritional requirements if meals outside the fasting window are not well balanced.
She particularly advised against prolonged fasting for people with diabetes, especially those taking glucose-lowering medications, as it increases the risk of hypoglycaemia and dehydration. Pregnant or breastfeeding women, children, teenagers, people with eating disorders, nutritional deficiencies or chronic illnesses should also avoid prolonged fasting unless medically supervised.

On acid reflux, Apte noted that there is no strong evidence to suggest that grains are a universal trigger for acid reflux. “Common reflux triggers are usually high-fat foods, spicy foods, chocolate, caffeine, mint, acidic foods and alcohol,” she explained.Story continues below this ad
She said symptom improvement after removing grains could instead be linked to reducing refined carbohydrates, processed foods, portion sizes or overall calorie intake. Weight loss itself and avoiding late-night meals may also contribute to relief.
“Removing grains broadly without identifying the actual trigger may unnecessarily restrict the diet,” she said, adding that some grain-based foods may cause discomfort in people with allergies or specific intolerances.
Dos and don’ts of intermittent fasting
For those considering intermittent fasting, Apte recommended assessing their health status, medications and nutritional needs before making significant dietary changes.
“It is better to start with a shorter fasting window instead of immediately attempting prolonged fasts. Meals during the eating window should remain balanced, providing adequate protein, fibre, healthy fats, vitamins and minerals,” she said.Story continues below this ad
Hydration remains essential throughout, she added. However, she warned that individuals with diabetes or other chronic conditions should consult their healthcare provider before beginning intermittent fasting, as changing meal timings can affect medications and blood sugar control.
She also advised seeking medical attention if fasting causes persent dizziness, fainting, severe weakness, vomiting or if there is unexplained weight loss, ongoing digestive problems or difficulty swallowing, rather than continuing dietary restriction.
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.