Benger’s Food was a commercial food powder to be mixed with milk that was popular in the first half of the 1900s. It was a bit more scientific than Ovaltine, however, as it was made with "wheat-flour and an extract containing the digestive ferments of the pancreatic juice." The digestive enzymes, when added to milk and heated, would start to break down the starches in the wheat into sugar and pre-digest the milk. The drink was allowed to sit for anywhere before 5-45 minutes before consumption, depending on the need of the patient. While earlier medicines based on digestive enzymes were available, this was the first popular product that treated them as a dietary supplement that anyone could purchase and use.
HOW BENGER'S FOOD IS SELF-DIGESTIVE
"Here is Benger's food in the process of preparation. Benger's food is the only food which scientifically combines the two all-important principles of digestion in a dormant state. When you commence to prepare the food by adding hot milk these become active. One modifies the milk, making it as light as snowflakes, the other acts upon the Benger's food, and, while you wait, the two combine in forming a most delicious food-cream, with a delicate biscuit flavor. You control the extent of digestion. You can carry it to the stage in which it passes into the system with little human aid, or, according to the condition of your patient, give the human digestion more work to do. The prepared Benger's food is so soothing as to allay internal irritation, and you can be sure that the milk and food served in this way will give all the nourishment that food can give. There is a world of difference between Benger's food and pre-digested foods. You must go from pre-digested foods to light, ordinary food at a bound, but with Benger's you can gradually increase the work of the stomach as it recovers its normal healthy activity. All chemists, etc.. sell Benger's food."
-- An advertisement posted in the Barrier Miner (Broken Hill, NSW), May 31, 1922.
Benger’s was intended especially for infants and invalids, but was a popular enough drink among the healthy. It was a simple and sweet drink, and had a halo of healthiness about it. Their brand was originally built around both ease of digestion for helping "backward children" grow stronger and being a delicious "food cream". Their marketing was so effective that many people remember it as having been enriched with vitamins and minerals, but as far as I can find this was not the case, and was not advertised as being the case.
During WWII it was advertised as being "a rich flavoring for soups, stews & gravies", and it was reportedly treated as a type of dried milk powder and food sauce by both civilians struggling with rationing and by troops in the field. It later had a significant nostalgia-based following due to wartime associations. It is also probable that it gained a cult following among people who had trouble digesting milk proteins.
There is surprisingly little firm information on Berger's Food. It first appeared sometime around 1880-90, and disappeared sometime around 1960. It was first produced in Manchester, and later in Holmes Chapel. F. B. Benger and Co. became Bengers Ltd. and later was bought by Fisons Pharmaceuticals in 1947, which carried on making Berger's Food while continuing to focus on research into new medicines. The Fisons Group dissolved in 1996, but it is likely that they stopped marketing Berger's Food at least two decades before this, and the most recent advertisement I can find is from 1954.
It is most likely that it contained amylase and trypsin throughout its production, and I have not been able to find references to any other active ingredients. Theoretically, you might make a good simulation by mixing extra fine wheat flour, modern enzyme powder, and milk.