This information is from a daily paper, and is from the foods standard agency

how much is too much
fat
20g of fat or more per 100g of food is a lot
5g of saturated fat or more per 100g of food is a lot
3g of fat or less per 100g of food is a little
1g of saturated fat or less per 100g of food is a little

salt
1.5g of salt or more per 100g of food is a lot
0.6g of sodium or more per 100g of food is a lot
0.25g of salt or less per 100g of food is a little
0.1g of sodium or less per 100g of food is a little

sugar
10g of sugar per 100g of food is a lot
2g of sugar per 100g of food is a little