The promise is incredibly seductive: “Shed 5.5 kg in just 3 days!” It’s the kind of headline that grabs your attention, especially before a big event or after a period of indulgence. You imagine yourself stepping on the scale and seeing a dramatically lower number, feeling lighter and triumphant.
But before you embark on any drastic plan, it’s crucial to understand the cold, hard truth: losing 5.5 kg of body fat in 72 hours is physiologically impossible.
Let’s break down what is actually happening to your body during such an extreme regimen, why it’s not the victory it seems, and the potential harm you could be causing.
The Shocking Truth: What Are You Actually Losing?
When you see the scale drop 5.5 kg in 3 days, you are not losing 5.5 kg of body fat. The math simply doesn’t add up.
To lose just 0.5 kg (1 lb) of pure body fat, you need to create a calorie deficit of approximately 3,500 calories. To lose 5.5 kg of fat, you would need a deficit of ~38,500 calories in three days. That means you’d have to burn over 12,800 calories more than you consume each day. For context, a person running a marathon burns about 2,600 calories.
So, what is that 5.5 kg? Primarily, it’s:
Water Weight (The Biggest Contributor): Your body is about 60% water. Carbohydrates are stored in your muscles and liver as glycogen, and each gram of glycogen holds 3-4 grams of water. Drastically cutting carbs, calories, or using diuretics (including “detox” teas) forces your body to burn through its glycogen stores, releasing all the stored water with it. This can account for 2-4 kg of the loss.
Digestive Contents: Extreme diets often severely restrict food intake. This means the weight of the food in your digestive system (and the waste waiting to be expelled) is significantly reduced. This can easily account for 1-2 kg.
A Tiny Amount of Muscle Mass: When you crash-diet, your body panics for energy. Since it can’t access fat stores quickly enough, it may start breaking down precious muscle tissue for fuel. Losing muscle is counterproductive, as it slows down your metabolism.
The moment you eat normally again, your glycogen stores replenish, water is retained, and your digestive system refills. The scale will bounce right back up—this is the infamous “rebound” or “yo-yo” effect.
The Dangerous Methods Behind Rapid Weight Loss
