How to express your deficit as a percentage of TDEE
A flat calorie number hides how hard the cut feels. The same 500 kcal is a big slice for a small body and a small slice for a big one. Here is how to turn your deficit into a percentage of what you burn, so the cut fits your own body.
You hear friends say, 'I am on a 500 calorie deficit.' That number sounds fixed. But 500 means one thing to a big active man. It means something else to a small quiet auntie. The honest way to compare is to turn your deficit into a percentage. You divide it by how much you burn in a day. This short read shows the maths. It is simple, and it makes the cut fit you.
The sweet spot is about 20 percent
A deficit is not a guess. It is a slice of what you burn in a day. Scientists tested how big that slice should be. A study watched people try different deficit sizes for six months. It found a 20 percent cut of daily burn works best. A tiny 10 percent cut was too weak. People lost weight so slowly they lost hope. So aim near 20 percent. Say you burn about 2000 kcal a day. A 20 percent cut is then 400 kcal. You eat about 1600 kcal. Sports doctors give the same idea in flat numbers. They say a safe cut is 500 to 1000 kcal a day.
A 500 kcal deficit works the same for every body.
mostly falsemostly false
Five hundred calories is the same amount of energy, yes. But it is not the same effort. Cut 500 from a 2000 kcal day. That removes one quarter of your fuel. Cut 500 from a 3000 kcal day. That removes only one sixth. The smaller body feels that cut much more. Two friends can both say 'I am 500 in deficit.' Yet they get very different results. The percentage tells the truth the flat number hides.
Different cut sizes for one body (burns 2000 kcal a day)
How to find your percentage in Burnie
The bottom line
A flat calorie number does not tell the whole story. A percentage does. Aim your cut near 20 percent of what you burn. On a 2000 kcal day that is a 400 kcal cut. Over a week that adds up to 2800 kcal. One kilo of body fat holds about 7700 kcal. So that is roughly 0.36 kg gone each week. Steady and safe. Work the maths for your own burn. Then the deficit finally fits you.