As with any diet, you’ll get the best results if you’re consistent. At the same time, you can certainly give yourself a break from this kind of eating schedule on special occasions. You should experiment to figure out which kind of intermittent fasting works the best for you. Lots of people ease themselves into IF with the 12-12 plan, and then they progress to 16-8. After that, you should try to stick to that plan as much as possible.
While these five methods are the most well-known in terms of integrating periods of fasting into your eating schedule, there are many other similar philosophies based on meal timing. For those who prefer a more fluid, less rigid method, there’s also the concept of eating intuitively. Primal Diet proponent Mark Sisson is a supporter of the Eat WHEN (When Hunger Ensues Naturally) method, where dieters simply eat whenever their bodies ask them to. However, some believe this can also lead to overeating or overconsumption of calories, since our bodies’ hunger-induced choices may be more caloric than otherwise.
How It Works: Fast for 24 hours once or twice per week. During the 24 hour fast, which creator Brad Pilon prefers to call a “24 break from eating,” no food is consumed, but you can drink calorie-free beverages. After the fast is over, you then go back to eating normally. “Act like you didn’t fast,” Pilon says. “Some people need to finish the fast at a normal mealtime with a big meal, while others are OK ending the fast with an afternoon snack. Time it however works best for you, and adjust your timing as your schedule changes,” he says.
In this example, lunch on Monday is your last meal of the day. You then fast until lunch on Tuesday. This schedule has the advantage of allowing you to eat everyday of the week while still reaping the benefits of fasting for 24 hours. It's also less likely that you'll lose weight because you are only cutting out two meals per week. So, if you're looking to bulk up or keep weight on, then this is a great option.
AN IMPORTANT CAVEAT: Intermittent Fasting can be more complex for people who have issues with blood sugar regulation, suffer from hypoglycemia, have diabetes, etc. If you fit into this category, check with your doctor or dietitian before adjusting your eating schedule. It also affects women differently (there’s a whole section dedicated to that below)
In fact, the authors of this book said that they had patients who only changed their eating habits with this twelve- to sixteen-hour “fruit” fast each day. They did not follow the diet’s other rules or count calories, and they still lost weight and got healthier. This strategy might have simply worked because the dieters replaced junk food with whole foods. In any case, people found this dietary change effective and easy to make. Traditionalists won’t call this fasting; however, it’s important to know that you may have options if you absolutely can’t abstain from food for several hours at a time.
It requires less time (and potentially less money). Rather than having to prepare or purchase three to six meals a day, you only need to prepare two meals. Instead of stopping what you’re doing six times a day to eat, you simply only have to stop to eat twice. Rather than having to do the dishes six times, you only have to do them twice. Rather than having to purchase six meals a day, you only need to purchase two.