This is a complicated question to answer, as the RN used a different system for feeding its sailors during WW1 than many of its sailors would experience 20 years later. In WW1, the RN was still on the old system of Standard Messing (technically the Standard Ration and Messing Allowance). Under this system, crews were divided into messes. Each mess was then provided with a standard ration, which usually included rice, flour, potatoes and vegetables, and a sum of money (the Messing Allowance). With this money, they could purchase anything else they wanted, either from Admiralty stores, or from the civilian market. The food was cooked by the individual messes, with two men from each mess serving as cooks on a rota basis. This meant that food quality was highly variable across the RN, depending on where the ship was stationed, and the culinary abilities of the men in the mess. A ship stationed in South Africa would have access to a very different set of foods to a ship stationed in India, New Zealand, or the UK. Similarly, a mess which contained men who were used to cooking would be eating very different food from those that contained only men with very little experience. However, the Admiralty did try to level out these imbalances, establishing supply depots at its bases, and providing sailors with recipes and cooking advice. The Standard Ration and Messing Allowance system was used throughout WW1. It would still be used on ships built in this period, and on destroyers, throughout the 1920s, 30s and 40s. The daily standard ration from 1913 can be seen here. Over the period, the standard ration changed somewhat. The increased provision of refrigeration meant that fresh meat could near completely replace the need to use salt beef or pork. From 1942, dehydrated vegetables would become more prominent, replacing fresh or frozen ones, but the amount of food in the ration was similar.

Corvettes, minesweepers and small craft used a very similar system, called the Victualling Allowance (this was also used by submarines in WW1). These vessels were too small to have their own accounting officer, who bought and provided provisions for the ship. Instead, they were provided with a sum of money to buy provisions from the accounting officer at the base from which they sailed. They were also able to buy from non-naval sources, giving more flexibility in their diet. Cooking was still done by the members of the mess.

However, from the entry into service of HMS Hood, the RN's newly built capital ships and cruisers used a different system. Known as General Messing, it was a much more centralised system. Rather than each mess buying and cooking food individually, the supplies were purchased by the ship's Accounting Officer. The food was cooked by specialist cooks in a central galley. The cooks from the messes were reduced to simply carrying the food from the galley to where the messes ate. Most ships did not have cafeterias, with the men eating in their quarters or at their stations. The newest ships, and those lend-leased from the Americans, did have cafeterias where the men could eat. The larger submarines built in the 1920s and 30s also used this system. It meant a much greater standardisation in food quality across the ship - now, the entire crew was guaranteed to be eating something made by somebody who knew how to cook. However, it still suffered from the same issue of geography as Standard Messing. Ships operating from ports where little or substandard supplies were available had to compromise on their provision of food. This was mostly a wartime problem, and only really a problem in places like Malta. Even then, crews were able to supplement their rations through official and unofficial means - 10th Submarine Squadron, operating on Malta, kept pigs at their base, while fishing, black marketeering and scrounging was common throughout.

The RN's provision of food was somewhat interrupted during both wars, as compared to peacetime. The desire to reduce the amount of shipping carrying food to Britain meant that ships operating from British ports had a lesser variety of options, and those options were frequently less appealing; sausages were often bulked out significantly with bread, fish choices tended towards the more easily caught than the familiar, and flour was often wholemeal rather than the usual white. However, the RN was always a high priority for food, and tended to get the best of what was available.