Quick, how much of that tub of yoghurt is a serving? Are you supposed to eat the whole packet of crisps at once or just some of them because it's a "family pack

Quick, how much of that tub of yoghurt is a serving? Are you supposed to eat the whole packet of crisps at once or just some of them because it's a "family pack"? The per-serving information is extremely crude and only good for a rough glance. If you want to be more precise, use the per-100g values or whatever they use in the US.