Avinash Tiwary and Farida Jalal on Sajid Nadiadwala's weight loss (Photo: Avinash Tiwary/Warda Khan S Nadiadwala/InstagramExpress Archives)Actor Avinash Tiwary recently revealed that he drew inspiration from O’Romeo producer Sajid Nadiadwala’s fitness transformation, which has taken the internet by storm since March 2025. “Have you seen Sajid Nadiadwala? His physique right now is insane. He’s walking around at 12 per cent body fat. I was worried that if I didn’t build my body fast enough, Vishal sir would cast him instead,” Tiwary told standup comedian Kapil Sharma on Netflix’s The Great Indian Kapil Show.Co-actor Farida Jalal, 76, slyly added, “He told me. Sajid bhai said, my waistline is 27 inches,” adding, “I did ask him all about it. I can’t reveal his answer.”While there is no official confirmation on whether he took weight loss drugs, here’s how emphasis on body fat and waist matters.Body fat percentage and waist circumference are numbers that often trend for visual reasons, but they carry important metabolic implications, said consultant dietitian and fitness expert Garima Goyal.Body fat percentage reflects how much of the body is composed of fat relative to muscle, bone and other tissues. “Maintaining a healthy body fat range is associated with improved insulin sensitivity, better cardiovascular health and reduced systemic inflammation. Lower body fat, when achieved through strength training and balanced nutrition rather than extreme dieting, typically indicates higher lean muscle mass and better metabolic efficiency,” said Goyal. Sajid Nadiadwala (Photo: Warda Khan S Nadiadwala/Instagram)Waist circumference, in particular, is a strong indicator of visceral fat. “Visceral fat is the fat stored around internal organs in the abdominal cavity. Unlike subcutaneous fat, which sits under the skin, visceral fat is metabolically active and closely linked to higher risks of type 2 diabetes, hypertension and heart disease. A reduced waistline often reflects lower visceral fat levels, which translates into improved long-term health outcomes,” noted Goyal.However, context matters. According to Goyal, extremely low body fat is not necessary or advisable for everyone. “For men, body fat around 10 to 15 per cent is generally considered lean and athletic. For women, healthy ranges are naturally higher due to hormonal requirements. The focus should not be on chasing a specific number, but on maintaining a range that supports energy levels, hormonal balance and overall wellbeing.”Story continues below this adAlso Read | ‘I run 5 km every day. Can I build a decent muscular body without going to the gym?’The key takeaway is that reduced body fat and a healthy waist measurement, when achieved through sustainable habits, signal improved metabolic health and lower risk of chronic disease. “Numbers like 12 per cent body fat or a 27-inch waist may draw attention, but what truly matters is how those results were achieved and whether they are maintainable in the long term.”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.