How big a deficit is safe when you have 20 kg to lose
When you have a lot to lose, you burn more energy each day, so you can run a bigger deficit than a small person. But there is still a ceiling, and crossing it brings gallstones and muscle loss.
You have 20 kg to lose. The number feels huge. You want it gone fast. So you wonder, can I just cut hard and finish in three months? Here is the honest answer. A bigger body can safely run a bigger deficit than a small one. But there is a ceiling. Cross it, and you lose muscle, not fat. Cross it more, and you risk gallstones. This short read is about where that ceiling sits for you.
The safe speed most bodies agree on
Health bodies agree on a steady pace. A safe loss is about 1 to 2 pounds a week. That is roughly half to one kilo. To get there, you eat 500 to 1,000 fewer calories than you burn each day. The first goal is small and clear: lose about 10 percent of your body weight over 6 months. For someone who weighs 100 kg, that is 10 kg. Slow and steady beats fast and brittle every time.
If I have 20 kg to lose, I can safely cut 1,500 calories a day and finish in three months.
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A huge cut feels brave. It is mostly a trap. Eat too little and two things break. First, you lose muscle along with the fat, so you end up weaker, not leaner. Second, your risk of gallstones jumps. Gallstones are small hard stones that form in your gallbladder when weight drops too fast. Doctors say steady loss under about 1.5 kg a week keeps that risk low. Cut harder than that, and the scale may move, but your body pays for it.
Why a bigger body allows a bigger deficit
Here is the part most people miss. A heavier body burns more energy each day, even at rest. More of you means more heat-making cells. So the same 1,000-calorie cut leaves you with more food on your plate than it would for a small friend. You can hit the safe speed of 1 kilo a week while still eating well above the floor. A small person cannot copy your number without dropping below their floor. Your deficit is yours, not theirs.
Your safe deficit depends on your size
How to find your safe number in Burnie
The bottom line
Yes, you can run a bigger deficit than a small friend, because your bigger body burns more each day. But the ceiling is the same idea for everyone: about 1 percent of your weight per week, and never above 1.5 kg. Pick the biggest cut you can hold while staying above the food floor. Lose 20 kg the steady way, and it stays off. That is the maths that wins.