To summarize, I think that they first have to make the healthy food cheaper, so more people can afford it. And if they have done this, than is it very good if they introduce the fat fax rule.
The input of fat tax is aimed to prevent obesity in Great Britain. Fat tax is meant to raise the price of fatty products, which will discourage people from eating fatty product. For example: fish and chips or hamburgers
The reason why this is important is because, it will become more and more difficult for humans to survive on earth. For example, most of us do not realise we are increasing climate change when we use the care too often. Therefore, it is important to know we have other planets where we can live in order for the human race to survive.