After looking online, I found a counter supposedly for grams: 匁(monme). Is this right? Also, would I just use it with the noun + particle + counter + verb form? Like 食べ物の一千匁をもって来る.
2 Answers
匁 is an old Japanese unit for weight and it's approximately equal to 3.75 g. See: Japanese units of measurement. It's almost never used today, and you can probably forget it for now.
To refer to grams, you have to say グラム, which is just a transliteration of 'gram'. Actually there is a kanji for 'gram', which is 瓦. But this is also almost never used in modern Japanese, and you should not use this.
When you want to use の, the correct syntax is number + unit + の + object (e.g., 5冊の本, 3人の先生). The correct sentence would be:
1000グラムの食べ物を持ってくる。
I bring 1000 grams of food.
Alternatively you can avoid using の and say:
食べ物を1000グラム持ってくる。
See the discussion here: How to list numbers of things
(I used Arabic numerals which are usually preferred in horizontal writings)
As in other languages, Japanese has various ways to express weight. The most popular terms are キログラム (kilogram) and グラム (gram). キロ is broadly used for キログラム, but you should note that it could also mean キロメートル (kilometer) and キロワット (kilowatt) depending on context.
[匁]{もんめ} is tricky and as far as I know, it is mainly used to refer to weight of precious metals such as gold or silver.
[斤]{きん} is 600 grams and it is mainly used for bread or meat.
You can read the linked Wikipedia article on Japanese units of measurement.
