About 1 kg of body fat equals about 7700 calories. So to lose 1 kg, you need to burn 7700 calories more than you eat

Weight loss is one of those topics everyone talks about but very few truly understand. We hear about new diets every week. Someone swears by cutting carbs. Someone else says “just walk 10,000 steps”. Then there are people trying detox drinks, intermittent fasting, or complicated meal plans. But at the end of the day, fat loss is not magic. It is simple body maths. And once you understand that maths, the whole process becomes far less confusing and a lot more doable.

A few weeks ago, Dr Arjun Sabharwal – a UK and India–trained kidney doctor who lost 40 kgs in two years – shared a video on Instagram explaining weight loss in the simplest way possible. 

The One Rule: Calorie Deficit

Dr Sabharwal started with the basics: “There is only one way to lose weight. That is calorie deficit.” According to him, 1 kg of body fat equals about 7700 calories. So to lose 1 kg, you need to burn 7700 calories more than you eat. That's it.

Simple Maths, Clear Results

He explained it with an example. If someone weighs around 80 kg, their body naturally burns about 2500 calories a day. Add exercise and you burn around 500 more, taking the total to about 3000 calories.

Now the food part:

• Eat 2500 calories → 500 calorie deficit → around 15 days to lose 1 kg
• Eat 1800 calories → 1200 calorie deficit → close to 1 kg a week

Nothing extreme. Just consistent choices.

Fat Loss vs Muscle Loss

Dr Sabharwal also pointed out that when weight drops, it is not only fat. Some muscle is lost, too. So he stressed the basics: increase protein, do resistance training, and stay regular at the gym. This keeps muscle safe and targets fat.

The Habit Phase

He summed it up simply: calculate and count your calories. The first week feels tough. The second week is easier. By the third week, it becomes a habit.

The message is simple. “This is not a crash diet. This is science," Dr Arjun Sabharwal concluded.