請教英文文法

(if you lose weight)~ (you should cut down on your diet)
你頭半部影響咗後半部~
因為你用現在式 lose weight，而之後又話要減少節食~

好confuse呀﹗﹗
你係「advice人哋去減肥」或者係「叫人唔好再減落去」呢？

1) 如果你係 advice人哋去減肥，你應該話：
If you want to lose weight, you should cut down on calorie.
(意思是：如果你想減肥，妳要減少卡路里的攝取。)
*(需要加 want to 同改用 calorie)

2) 如果你想叫人唔好再減落去：
If you lost weight successfully, you should cut down on your diet.
(意思是：如果你減肥成功，就要減少節食了。)
*(需要改用 lose的過去式 同加上 successfully 等的副詞)

You should keep diet if you want to lose your weight.

If you want to lose weight, you should go on a diet programme.