Matsvinnet och matavfallet måste minskas.

They are related, but not exactly the same.

matsvinn usually means food that could have been eaten but gets thrown away anyway, so it emphasizes avoidable waste.

matavfall is broader and usually means food waste as refuse, including things like peels, bones, eggshells, or coffee grounds.

So in many real-life contexts:

• matsvinn = unnecessary wasted food
• matavfall = food waste in general, especially what ends up as waste to be collected or sorted

Because both nouns are in the definite singular form.

In Swedish, definite nouns usually add the definite ending to the noun itself instead of using a separate word like English the.

Here:

• ett matsvinn → matsvinnet
• ett matavfall → matavfallet

Both are ett-words, so their definite singular ending is -et.

Yes. Swedish uses compound nouns very often.

These are built like this:

• mat + svinn → matsvinn
• mat + avfall → matavfall

The last part is the main noun, and it decides the grammatical gender and how the word is inflected.

So:

• svinn is the core of matsvinn
• avfall is the core of matavfall

That is why the definite forms become matsvinnet and matavfallet.

Because Swedish normally puts definiteness on the noun itself.

So matsvinnet already means the food waste or food waste in a definite/generic sense, and matavfallet already means the food waste / the food refuse.

A separate article such as det is not used here, because there is no adjective. You would only get a separate definite article in a phrase like:

• det onödiga matsvinnet = the unnecessary food waste

Måste means must or have to.

It does not change depending on whether the subject is singular or plural, because Swedish verbs do not agree with the subject in number the way English verbs sometimes do.

So Swedish uses the same verb form with:

• matsvinnet måste minskas
• matsvinnet och matavfallet måste minskas

The subject becomes larger, but måste stays the same.

Because the sentence is using the passive idea: must be reduced.

• minska = decrease / reduce
• minskas = be reduced

So:

• måste minska = must decrease
• måste minskas = must be reduced

That is an important difference.

In this sentence, the meaning is that these things need to be reduced, possibly by people, companies, or society in general. That is why the passive form minskas is used.

Here it functions as an infinitive, because modal verbs like måste are followed by an infinitive.

So the structure is:

• måste + minskas

The tricky part is that the passive infinitive and the present passive often look the same in Swedish. In this sentence, after måste, it is understood as the infinitive: must be reduced.

Because modal verbs in Swedish normally take the infinitive without att.

That includes verbs like:

• kan
• ska
• vill
• måste

So you say:

• måste minskas

not:

• måste att minskas

This is very similar to English must reduce rather than must to reduce.

Yes, that is possible in some contexts.

Both versions can occur, but they feel slightly different.

• Matsvinnet och matavfallet måste minskas can sound like you are talking about these as recognized categories or as topics already under discussion.
• Matsvinn och matavfall måste minskas can sound a bit more general, headline-like, or abstract.

So the definite form here is natural, but the indefinite/generic version is also something you may see.

Yes. You could also say:

Matavfallet och matsvinnet måste minskas.

The basic meaning stays the same. The order mainly affects emphasis or style.

Swedish often puts the element first that the speaker wants to foreground slightly. So the original order may simply reflect that matsvinnet is the more prominent issue in that context.