I should note that food labels in Japan aren't always consistent, as you'll see below, and although, for example, you'll usually see information about the total calories, protein, fat, carbohydrates and similar main nutrients, you won't always see much about other minerals or vitamins (though things like fortified cereals, breads, etc., often list these).
I've also tried to include a variety of words you'll see, but some terms/phrases are worded slightly different, although the meaning is generally the same, e.g., "賞味期限" and "消費期限" both mean "best before; best eaten by" or the expiration date.
Also note that throughout the post I have not broken down kanji and words as I normally do - instead, the vocabulary charts break them down, so please reference the charts for a breakdown. (You can also use the "find" feature on your browser and copy/paste a word you want to see in the chart to find it quickly.)
So let's get on with it: how do you read food labels in Japan?
More information under:
Ministry of Agriculture, Forestry and Fisheries