By now, you’ve probably heard about this trendy diet, or rather a style of eating that involves extended periods of low or no food consumption. It's one of the most popular weight loss plans right now, but if you’re wondering how this type of diet can be beneficial — or even doable — you’re not alone. Isn’t breakfast the most important meal of the day after all? According to nutrition experts, intermittent fasting, or IF, can have some potential benefits, one being improved metabolic health. It’s believed that the fasting period gives the body the time it needs to properly process food and burn excess fat stores.
“If someone has metabolic syndrome, for example, the prolonged overnight fast may be one way to improve their health,” explains Suzanne Dixon, registered dietitian with The Mesothelioma Center at Asbestos.com. “Along with lowered insulin levels, health experts and researchers have noted decreases in blood pressure, cholesterol levels, weight, waist circumference, and inflammation in the body.” This leads many to believe that intermittent fasting can also help protect against diabetes, heart disease, and cancer. Still, she acknowledges that much more research needs to be done to ensure a positive cause and effect relationship regarding IF.
If you’re considering intermittent fasting, here are some things to keep in mind to ensure you’re doing it safely and effectively.
Build up to it
If you normally go about eight hours between the last meal of the evening and the first meal of the following day, Dixon warns not to try and jump right into a 13-hour overnight fasting window. “That change is very abrupt, and it's unlikely you'll feel good going five hours past the time you normally eat in the morning,” she says. Instead, she recommends cutting off your eating 30 minutes earlier than usual in the evening and waiting an extra 15 to 30 minutes past the time you usually eat breakfast. “If you can do this without too much trouble, continue doing it for a few weeks until it feels natural and comfortable,” she says. “Then, extend the window of 'not eating' on either or both sides — evening and morning — by another 15 minutes.”
You’ll likely be hungrier
Especially in the earlier stages of trying an intermittent fasting approach, you can expect your appetite to seem high. “As you get used to the fasting periods, it gets easier, but the first few weeks will likely be the most difficult,” says Roger E. Adams, PhD, personal trainer, doctor of nutrition, and owner of eatrightfitness. To help stay on track, it’s best to avoid any temptations during these periods of fasting, so that you’re not inclined to reach for something unhealthy.
Avoid stocking up on junk food
Make your life easier and stock your cabinets and fridge with healthy foods to avoid binge episodes, suggests Dr. Adams. “I would recommend stocking your house full of healthy fruits, veggies, lean meats, dairy, and whole-grains, and throwing away those coupons for the all-you-can-eat buffet, so you’re not so tempted to binge when you break your fast.”
Exercising may be harder than usual
You need a ton of energy stored up in order to experience a hard-won workout. While you might have enough of this energy and motivation after breaking the fast, you will likely have very little energy during your fast. This, Dr. Adams explains, can lead to erratic workout schedules, lack of progress (workouts build upon themselves, especially if you’re training for an endurance event), and feelings that you should workout harder or longer since you just binged on a lot of calories.
You’re going to feel a bit “off”
Headaches, dizziness, moodiness, lethargy, and constant thoughts of food are just some of the common symptoms of transitioning to the IF strategy, notes Dr. Adams. “Just as your body gets used to you eating throughout the day, it will take time for it to get used to the fasting periods.” He recommends starting with shorter fasting periods in the beginning and slowly stretching out those fasting periods as your body adjusts.
Consider taking a multivitamin
If you’re not taking one already, now is the time to start. “Because intermittent fasting restricts calories, you won't be taking in all the food and nutrients your body needs in order to stay healthy,” says Toby Amidor, MS, RD, author of Smart Meal Prep For Beginners. Before starting, she recommends speaking with a registered dietitian or your physician about taking a multivitamin to help prevent deficiencies, especially if you plan on sticking to the diet for a long time.
Be careful not to overeat post-fast
This is critical to reaping potential metabolic benefit from this type of eating plan, says Dixon. Unfortunately, this is not easy to do, since you’re fighting basic biology. “Hunger hormones can have incredibly powerful effects on behavior and food choices,” she says. “All the behavioral training in the world won't get that job done in terms of keeping a person from overeating post-fast if they have a history of disordered eating.”