Longer term fasting can precipitate gout but this should not occur with intermittent fasting (IF). On the other hand gout is associated with metabolic syndrome (obesity, insulin resistance, high cholesterol, high blood pressure) and 5:2 should help correct metabolic syndrome, partly through weight loss but also by the reduction in insulin levels. In addition IF seems to reduce inflammation.
Drink lots of fluid as dehydration will make it worse. Also avoid fructose, ie added sugar.
In general reducing purine rich foods can reduce risk of gout ie anchovies, sardines, kidney, liver, Asparagus, Cauliflower, Kidney beans, Lentils, Lima beans, Lobster, Mushrooms, Oatmeal, Peas, Spinach and alcohol.