Who should not do a crash diet (very low calorie)

A wedding is coming, or a holiday, or you just want to feel lighter. Someone on Instagram shows a '500 calorie challenge' and says they lost 5 kg in a week. It looks easy. It looks fast. But eating very little food, like 800 calories a day or less, is not a small thing for your body. Doctors call this a very low calorie diet, or VLCD. For some people it can be useful, but only under a doctor's watch. For many people it is genuinely unsafe without supervision. This article tells you honestly who should not do a crash diet, what can go wrong, and what a safer path looks like. The short rule: if you have any health condition, or you are pregnant or older or still growing, talk to your doctor before you cut food that low.