In the medieval diet, you may eat, by volume:
60% raw or slightly cooked vegetables native to Western Europe
20% cheese or meat
20% whole grain carbohydrates, preferrably oats, barley or wheat
There's not really a limit on what you can eat, but most people were under 2000 calories a day. With the percentages above, that's a lot of food.
Also, it's assumed you're walking at least six miles a day in total.
With this diet, you will lose weight and keep it off, while building muscle and keeping organs healthy. How does it work? It's what your species evolved on, esp. if you're European, and it provides a very simple digestive path that creates little excess and moves with an easy balance through the system.
Try it for a week
