Potatoes, corn, peas, pumpkin and beans are some examples of starchy foods that you must avoid in order to stay in a state of ketosis.
If you eat a carb-restricted diet and do an intense workout, you could be in ketosis within an hour -but we all react differently.
Therefore, it is not ideal to consume only fatty foods like bacon and butter - you are going to want to source most of your fat from plant-based foods. During the initial week or so of my current keto adventure my stomach was not very happy. I didn’t have pain or discomfort, but after eating a high fat meal I immediately had to use the bathroom.