How does Wilde use food as a way to satirze the aristocracy?

As a society, Victorians were snobby and classicist down
to how to hold a fork down, the types of foods they ate, and the amount that they
served. More, opulent, excessive, and hyperbolic always meant "wealthy" or
"fashionable".

Lady Brackell ate "crumpets" with the
Duchess, and the famous cucumber sandwiches are symbols of
status.

In the famous showdown between Gwendolyn and
Cecily, food made all the difference. Cecily's cake and sugar were "unfashionable" and
"unseen in the households of the best families", whereas her bread and butter and her
unsweetened tea were apparently the "rage" in London.

readability="37">

Cecily. 
[Sweetly.]  Sugar?

Gwendolen. 
[Superciliously.]  No, thank you.  Sugar is not fashionable any more.
[Cecily looks angrily at her, takes up the tongs and puts
four lumps of sugar into the
cup.]

Cecily.  [Severely.] 
Cake or bread and
butter?

Gwendolen.  [In a
bored manner.]  Bread and butter, please.  Cake is rarely seen at the best houses
nowadays.

Cecily.  [Cuts a
very large slice of cake, and puts it on the tray.]  Hand that to Miss
Fairfax.

[Merriman does so,
and goes out with footman.  Gwendolen drinks the tea and
makes a grimace.  Puts down cup at once, reaches out her hand to the bread and butter,
looks at it, and finds it is cake.  Rises in
indignation.]

Gwendolen.  You
have filled my tea with lumps of sugar, and though I asked most distinctly for bread and
butter, you have given me cake.  I am known for the gentleness of my disposition, and
the extraordinary sweetness of my nature, but I warn you, Miss Cardew, you may go too
far.

The drama caused by
these simple elements shows the sarcasm with which Wilde described the idleness and lack
of real worries of aristocrats, and their ridiculous and excessive behaviors are mainly
represented in Algernon.

Algernon's excesses as well as his
living above his means, eating without control, and running away of his debtors are
representative of how half of the so-called polite, upper classes of Victorian society
actually lived. Algernon is used as a sample of this noble society, and his habits are
indeed a mockery of those other aristocrats who lived among above their means, and yet
went into debt to entertain, eat, and live in opulence and
excess.

Algernon's specific constant eating is a reflection
of how he lives his life: To the fullest, literally. Similarly, his hunger is also
another reflection of how he lives: Always wanting more.