Most of us clearly understand how fat enters the body – usually through our favourite indulgences. But have you ever stopped to think about how fat actually leaves the body once you start losing weight? The truth is far more interesting than most people realise, and it even challenges some common beliefs about weight loss. In an Instagram post, nutritionist Pooja Makhija rekindles interest in the science of fat loss by addressing the topic of how fat leaves the human body after weight loss. “Most people are shocked to learn that fat leaves the body mostly through your lungs,” Pooja writes in the caption.
“We all know how fat enters our body — samosas, gulab jamun, malai kulfi,” Pooja begins the video, adding a touch of humour to show how easily high-fat foods slip into our diets. Understanding how fat leaves the body is a lesser-known part of weight management that goes beyond dietary choices.
To explain this, Pooja breaks down fat at the molecular level. Lipids are biological molecules made of carbon, hydrogen, and oxygen, and they make up fat tissue. By storing energy in their chemical bonds, these molecules act as the body's long-term fuel reserves.
“When you exercise or eat smart — not diet — you break these bonds to release the energy,” she explains. Many people assume fat simply "melts away", but the truth is the body must convert it into another form because it cannot be destroyed.
Pooja says that 80% of the fat we burn leaves the body through our breath, which is supported by well-known metabolic research. During metabolism, fat breaks down into carbon dioxide and water. Each exhale releases carbon dioxide.
“So, the next time you're huffing and puffing on the treadmill, please remember you are literally exhaling out your fat,” she says, highlighting the importance of steady movement, especially cardio.
The remaining 20% of metabolised fat exits the body as water – through tears, sweat and urine. This is why most weight-loss plans still focus on regular exercise and staying properly hydrated.
In her caption, Pooja further explains that oxygen is the real fuel for burning fat. “The more efficiently your body uses oxygen — through deep, steady breathing during moderate exercise — the more fat you oxidise.”
She also notes that breathing technique matters. Shallow mouth breathing reduces the efficiency of fat oxidation and oxygen transport. “Try nasal or diaphragmatic breathing during workouts for better oxygen exchange and endurance,” Pooja advises.
Ending with a motivating message, she says: “Inhale discipline, exhale fat.”
Understanding how fat truly leaves the body can make your fitness journey feel a little less confusing and a lot more empowering.
Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your doctor for more information. NDTV does not claim responsibility for this information.
