Why is it so hard to lose those last five pounds?

Why is it so hard to lose those last five pounds?
Today is no scales day on the world,so I would like to ask both you this question.please answer it in English.
If noone can answer,I will give the answer.
the answer:There are several reasons.The more you weigh,the more calories your body needs to sustain itself,hence the more calories you use.Also,the more you weigh,the more calories you probably take in on a daily basis,making it easier to cut calories from the total without endangering your health.The closer you are to your target weight,the greater the amount of exercise you need to wear off those final pounds.It's important to be patient; if you continue to watch your food intake and exercise several times a week,eventually the pounds (or kilograms) will come off.Sometimes,though,we have to sit back and accept ourselves at the size and shape we are and not worry about our weight.There is no ideal body shape or size.