Personally, I just try to eat a salad first since if i eat anything else (fat or protein) I have to rush to the bathroom. But there is no problem breaking your fast with fatty foods if you go slowly.
From Jason Fung’s book on fasting :
“Break your fast gently. The longer the fasting period, the gentler you must be. There is a natural tendency to overeat as soon as the fast is over—though, interestingly, most people say that this isn’t because of overwhelming hunger but more of a psychological need to eat. Overeating right after fasting often leads to stomach discomfort. While not serious, it can be quite uncomfortable. This problem tends to be self-correcting. Try breaking your fast with a snack or small dish to start, then wait for thirty to sixty minutes before eating your main meal. This will usually give time for any waves of hunger to pass and allow you to gradually adjust to eating again. Short-duration fasts (twenty-four hours or less) generally require no special precautions, but for longer fasts, it is a good idea to plan ahead. Prepare a small dish and leave it in the refrigerator so that when it comes time to break the fast, you are ready and less likely to be tempted by the myriad of other convenience foods available. Here are some suggestions for that first snack:
1/4 to 1/3 cup macadamia nuts, almonds, walnuts, or pine nuts
1 tablespoon peanut butter or almond butter
A small salad (instead of salad dressing, try cottage cheese or crème fraîche)
A small bowl of raw vegetables with some olive oil and vinegar drizzled on them
A bowl of vegetable soup
A small amount of meat (for instance, three slices of prosciutto or a slice or two of pork belly)
For those who experience gastrointestinal distress when breaking a fast, eggs seem to be the biggest culprit. If you have a sensitive stomach or are concerned about breaking your fast, you may want to avoid eggs at your first meal.
Tips for Breaking Your Fast with a Snack
• Make sure your portion sizes are small. You will be eating a full meal shortly, so there is no need to gorge.
• Take the time to chew thoroughly. This will greatly help your digestive system, which has been resting for a while. You are slowly bringing your system back online.
• Take your time in general. Your fast is over. If you are feeling anxious to eat again, take comfort knowing you will be having a whole meal within the hour.
• Don’t forget to drink water! Drink a tall glass of water before you break your fast and after your first meal. People often forget to consume fluid once they stop fasting, but we often mistake thirst for hunger. Make sure you are staying hydrated so you don’t overeat.”