There’s the 5:2 model (eat normal calories five days a week and only 500 calories the other two days); alternate-day fasting (one day you eat normally, the next you eat very little); OMAD (as in “one meal a day”); and then there’s 16:8 fasting, which limits food to an eight-hour eating window each day. This eating schedule comes with all the benefits of other fasting schedules (plus, recent research finds that it may lower blood pressure). Perhaps even better, you pick the eating window. So what should that eating window be? “There’s actually infinite variability. It can be any time. Any time that you don’t eat—that’s fasting,” explains Jason Fung, M.D., fasting expert and author of the book The Complete Guide to Fasting. If you can’t live without breakfast, slot your food earlier in the day (8 a.m. to 4 p.m.). If you prefer an early dinner, eat in the middle of the day (11 a.m. to 6 p.m.). If you’re someone who regularly goes out with friends for late dinners, schedule your eating hours later in the day (1 p.m. to 9 p.m.). Contrary to popular opinion, there are no rules around how many meals you have to squeeze in or whether or not you have to include breakfast. In fact, no data actually proves breakfast makes you healthier1 or weigh less2. “I suggest starting with a 12-hour daily fast and easing into a 16-hour fast," says Vincent Pedre, M.D., a functional medicine physician and gut health expert who often recommends IF to his patients. “Leave alternate-day and 20-hour fasts to people who’ve done it for a while.” Some experts suggest starting just a couple of days a week and working your way up, while others recommend gradually increasing your fasting window from 12 to 14 to 16 hours. “It’s important to listen to your body,” Pedre adds. Even though food is off-limits during fasting hours, non-caloric drinks and exercise are not. Research says they could even stave off hunger. For liquids, that includes water, black coffee, and unsweetened tea (just skip the cream and sugar). What’s more, exercising in a fasted state3 can supercharge your body’s fat-burning potential—but again, listen to your body. “If you feel too weak to work out from fasting, then you should take care of your nutrition and work out later,” Pedre cautions. It’s typically recommended by RDs to eat a small number of carbohydrates before exercise so you don’t burn out too quickly. “During your periods of eating, you need to stick to whole foods,” says functional medicine expert Will Cole, D.C., IFMCP, “Since some of the benefits of fasting include reduced inflammation, loading up on junk food during your eating window can perpetuate this inflammation. And with inflammation being the underlying contributing factor in almost all modern-day health problems, this is something you definitely want to keep under control.” That means yes to proteins, healthy fats, and carbohydrates from whole food sources. Skip the ultraprocessed foods and drive-thru; just don’t skip the focus on delicious. With less time spent on food prep and planning, it may even make you more creative in the kitchen. Here’s an idea of what to eat (and when to eat it) on a 16:8 fasting diet, depending on which eating window you choose: Experts recommend you ease into fasting and as always, speak with your doctor to determine the right plan for you. If you are pregnant or breastfeeding, avoid fasting altogether as fasting promotes fat burning and fat is essential for pregnant women. It can also lead to reduced milk supply and inadequate nutrient intake for both mom and baby. Additionally, if you have a history of an eating disorder, you should also avoid fasting as it can be triggering for anyone with a history of eating disorders. According to board-certified internist Vincent M. Pedre, if you have gut issues, food sensitivities, sleep disturbances, anxiety, or chronic stress, fasting can sometimes trigger your fight-or-flight response, which may exacerbate these issues. To ensure it’s right for you, start with just a couple of days a week and work your way up. Be sure to listen to your body, though. If you feel lightheaded or weak, or you feel like fasting is impairing your day-to-day activities, always eat something. As always, consult your doctor or dietitian to determine the right plan for you. RELATED STORY: Does Intermittent Fasting Help With Healthy Weight Loss?
