The Cunard Line's Commodore Robert G. Thelwell explains a typical meal:
Lunch brought me face to face with the splendid menus provided in the big Atlantic ships, and as the years went by I had to live with the concomitant, my increasing weight.
I suppose it is inevitable for diet to become an obsession with most captains of the big liners after a year or two. It did with me. I like my food. In my time as an officer of the Merchant Navy, the food at sea has often been indifferent, sometimes scanty. We learnt to take it as it came and not fuss too much about it. But to captains of luxury liners, the best food in the world, cooked by the best chefs, is available at the push of a button and my idea of a satisfying meal became a few blue-point oysters, a little turtle soup followed by fillet of sole meuniere, breast of Rouen duckling and a savoury of fried Camambert. No wine, of course. Except on special occasions, I never drank wine at my table.
The Commodore then points out the ill-effects of such extravagance (even without wine):
Such a diet, repeated twice daily, with snacks in between, soon added inches to my waist-line and I quickly realized that the best of menus must be varied with a far more simple regimen. A captain's work keeps him agile and I never failed to perform a 'daily dozen' in my cabin. I substituted a plate of lean bacon and tomatoes for the chef's splendid five-course lunch, but it was no good. I was becoming a roly-poly of a man and mentioned casually at my table that a diet seemed the only answer to my weight problem.
In no time word went round the ship that I was to go on a diet and at once I was overwhelmed with advice. No nation in the world is more diet-conscious than the Americans and diet sheets quickly began to rain on me. I could not believe what I had started. People stopped me as I walked around the ship and took me aside at parties to give me advice. I remember a voyage when all but one of the passengers were Americans and the women watched me with friendly censoriousness as I ate. "That little potato is worth two hundred calories to you, Captain," said a woman reproachfully.
Commodore Thelwell's weight problem was soon remedied, however, when he picked up a leaflet in London that gave menus guaranteed to shed pounds. After about two voyages he found himself boasting about his weight loss and had the pamphlets reprinted on his ship to be distributed to health conscious passengers. Commodore Thelwell, however, always made sure to point out that it was put together by British know-how.
References: Commodore Robert G. Thelwell, I Captained the Big Ships, comp. Robert Jackson (London: Arthur Barker Limited, 1961), 123-125.