it was 'better' to be eating - it gave one something to do

The organization where Letty and Marcia worked regarded it as a duty to provide some kind of a retirement party for them, when the time came for them to give up working. Their status as ageing unskilled women did not entitle them to an evening party, but it was felt that a lunchtime gathering, leading only to more than usual drowsiness in the afternoon, would be entirely appropriate. The other advantage of a lunchtime party was that only medium Cyprus sherry need be provided, whereas the evening called for more exotic and expensive drinks, wines and even the occasional carefully concealed bottle of whisky or gin – 'the hard stuff', as Norman called it, in his bitterness at being denied access to it. Also at lunchtime sandwiches could be eaten, so that there was no need to have lunch and it was felt by some that at a time like this it was 'better' to be eating – it gave one something to do.

Barbara Pym

Quartet in Autumn (1977)

I wrote a little about why I liked this book a lot here.

a glass of milk and a bun

If Henry hadn't been determined to quarrel he would have taken her out to lunch first, and now she would have to go and have a glass of milk and a bun in a creamery with a lot of other women who were having buns and milk, or Bovril, or milk with a dash of coffee, or a nice cup of tea. It was a most frightfully depressing thought, because one bun was going to make very little impression on her hunger, and she certainly couldn't afford any more.

Patricia Wentworth

The Case is Closed (1937)

Not my favourite Wentworth - that is perhaps

 The Case of William Smith or Lonesome Road?

she always felt cheerier at breakfast

'How can you eat that sawdust, Father?' she inquired, beginning on eggs and bacon and speaking cheerfully because it was a fine morning and only ten minutes past nine; and somehow, at the beginning of every new day, there was always a chance that this one might be different from all the rest. Something might happen; and then everything would be jollier all round.

Madge did not see clearly into her feelings; she only knew that she always felt cheerier at breakfast than at tea.

...

'What time did you say Viola's train gets in?' Tina asked her mother; she sometimes found the Wither silences unendurable.

'Half-past twelve, dear.'

'Just in nice time for lunch.'

'Yes.'

'You know perfectly well that Viola's train gets in at half-past twelve,' intoned Mr Wither slowly, raising his eyelids to look at Tina, 'so why ask your mother? You talk for the sake of talking, it's a silly habit.' He slowly looked down again at his little bowl of mushy cereal.

'I'd forgotten,' said Tina. She continued vivaciously, at the silence. 'Don't you loathe getting to a place before twelve o'clock, Madge – too late for breakfast and too early for lunch?'

Stella Gibbons

Nightingale Wood (1938)