Curious About Intermittent Fasting? Try The 16:8 Or 14:10 Schedule First

Is intermittent fasting safe for women?

Intermittent fasting isn’t a hard yes or no for all women. For example, fasting may positivity effect fertility and quality of life for women with PCOS, according to a 2022 review in the journal Nutrients, but the research is limited at this point and more evidence is needed to back this up. And there are a lot of variables at play, like if a woman is menstruating or in menopause, and which IF diet she tries. So, always talk with your doctor or a registered dietitian to make sure it’s a good fit for you, stresses Coogan.

Which is the best intermittent fasting schedule for women?

There aren’t necessarily schedules that are better suited for men versus women. Weight loss benefits of alternate day fasting were basically the same and similar changes in health markers like blood pressure were observed across genders, a 2020 study found.

A pro tip from Coogan: For women between the ages of 20 and 50, the most sustainable schedule is the 16:8 or the 14:10 diet, where you fast for 14 hours and have a 10-hour eating window. (And sustainability = key to success!)

On the flip side, the 5:2 diet, in particular, comes with downsides: “The brain needs a minimum of 130 grams of carbohydrates just to do its basic functions for the day, which comes out to about 520 calories, so if you do the 5:2 diet, you’re already at that limit for your day just in carbohydrates,” she explains.

Can you lose weight with intermittent fasting?

Research has found a link between intermittent fasting and weight loss, but there isn’t much research to prove that intermittent fasting is a better weight loss method than other diets. For example, intermittent fasting had similar weight loss results to a traditional calorie-restricted diet in a meta-analysis published in the JBI Database of Systematic Reviews and Implementation Reports in 2018.

In some cases, even when intermittent fasting did lead to weight loss, it wasn’t the most sustainable diet. For example, people who fasted every other day for a year only lost slightly more weight than those who ate a restricted-calorie diet on a daily basis, one randomized clinical trial of 100 metabolically healthy, obese adults published in JAMA Internal Medicine in 2017 found. The difference in weight loss was so small that it wasn’t considered clinically significant, and 38 percent of people in the alternate-day fasting group had trouble sticking with the diet.

It’s also worth pointing out that weight loss due to intermittent fasting isn’t guaranteed to last. “Some people may experience weight loss in the short-term, but many people eventually gain that weight back,” Rumsey says.

And, most intermittent fasting research has only been done on people who are obese. “There is almost no credible research that shows intermittent fasting is good for people at a healthy weight,” says Keatley.

Are there any long-term health benefits of intermittent fasting?

There is a growing body of research that suggests intermittent fasting does have health benefits outside of weight loss. Specifically, intermittent fasting was linked with lower insulin levels and blood pressure in a study published in Cell Metabolism in 2018. Researchers followed a small group of obese men with prediabetes—some were put on a 16:8 diet, while others ate over a period of 12 hours. Both groups didn’t gain or lose weight. But after five weeks, the men in the 16:8 group had much lower insulin levels and better insulin sensitivity. They also significantly lowered their blood pressure and said they had decreased appetites. They weren’t as hungry as they were before—even though they were fasting.

It might seem counterintuitive, but appetite control is a big benefit of fasting: People who ate only during a six-hour window, compared to following a normal eating schedule, felt less hungry than the control group, even though both groups ate the same amount of calories, a study in the journal Obesity showed. Intermittent fasting has also been linked to increased neuroplasticity, or the brain’s ability to form new synaptic connections and fight injury.

Unfortunately, there hasn’t been a ton of research on humans that follows the effects of intermittent fasting long-term. While some studies have followed participants for a year, that’s about as long as most go. It’s a slightly different story when it comes to rats. “In rodents, intermittent fasting has been shown to prevent age-related diseases, including tumors, heart disease, diabetes, dementia, and even extend lifespan,” says Keatley. But, he adds, “there is a big difference between rats and humans, and the research does not show these benefits enough to actually recommend it as the fountain of youth.”

What foods can I eat and what do I have to avoid?

This is a huge perk of intermittent fasting: You technically don’t have to alter what you eat—you just have to eat within a certain window of time. “On an intermittent fasting diet you don’t need to avoid any foods,” Gans says. “However, one should focus on consuming foods that are high in fiber and healthy fats for satiety, such as quinoa, black beans, spinach, strawberries, avocado, and almonds, and of course other nutrient-dense foods for overall health.”

At the same time, it’s a good idea to limit sugary drinks, processed foods, and simple carbs like white bread, advises Cording. “They’re not providing you with much nourishment,” she says. “You really want to focus on foods that do you a favor.”

That said, plenty of people have paired intermittent fasting with another type of diet, like keto. Again, it’s not a requirement, but doing intermittent fasting while also altering your diet could help you get results faster.

Does intermittent fasting have any side effects?

There are a few things that can happen when you follow an intermittent fasting diet. One thing to note is that fasting can interfere with your hunger cues. “Since people are only allowing themselves to eat in a certain window of time, they are completely ignoring their internal cues of hunger,” Rumsey says. “It causes people to disregard hunger cues, which then means once they are ‘allowed’ to eat, they are starving and it can be hard to stop eating.” This could lead to an unhealthy obsession with food for some people, Rumsey says.

Some fasters find that the diet makes them feel sharper and more alert, but alternately, fasting for long periods can also lead to mental fogginess, disrupted sleep, and decreased alertness, Rumsey says. And, she adds, fasting for extended periods of time “takes a large toll on your blood sugar levels,” causing you to flip-flop between low blood sugar and a spike when you eat again.

Who should not try intermittent fasting?

Coogan would not recommend intermittent fasting for anyone over 65. “For ages 40 and 50, you may be able to see some benefits, but as men and women get older, especially into their 60s, they start to naturally lose more lean muscle mass and over time appetite may start to decrease, so I would never want to see someone restrict even further,” Coogan says.

And if you take any medications, always clear intermittent fasting with your doctor since certain meds may cause nausea or stomach irritation if taken on an empty stomach.

Should I try intermittent fasting?

It really depends. If you feel like you have a healthy relationship with food and you do well with parameters, it could be a good fit for you. It’s certainly not an easy diet if you hate the feeling of being hungry, but the fasting periods do get easier with time, Angelone says.

While anyone can try intermittent fasting, ultimately, people who are overweight and/or have high blood pressure or high cholesterol (but are otherwise healthy) are considered the best fits for the diet, Angelone says.

You’ll also want to take a pass if you’re pregnant or breastfeeding or if you have a history of disordered eating, says Cording. “It can be a bit of a slippery slope into disordered patterns,” she explains.

How do I start?

There’s no magic plan to follow with this, but you could try to figure out a form of intermittent fasting that makes the most sense for you. Again, the 5:2 diet can be tricky, given that it involves calorie restriction for an entire day at a time, so it might be better to start with something like the 16:8 diet and progress from there if you feel good.

You also want to define what you’re hoping to get out of intermittent fasting, and it doesn’t hurt to check in with an expert, like your doctor or a dietitian, before you dive in. “Work with a professional who understands your goals and can help you determine what you need to eat for a diet like this to achieve [them],” says Keatley. Then, he recommends shooting for “small changes and small gains, as these are most likely to do the least harm and provide the most long-term benefits.”

Above all, listen to your body. If you feel like you’re hungry all the time and are kind of miserable, it probably isn’t the right fit for you. If you love the simplicity and you’re seeing the weight loss or health results you want, fast away.

Korin Miller is a freelance writer specializing in general wellness, sexual health and relationships, and lifestyle trends, with work appearing in Men’s Health, Women’s Health, Self, Glamour, and more. She has a master’s degree from American University, lives by the beach, and hopes to own a teacup pig and taco truck one day.

Andi Breitowich is a Chicago-based writer and graduate student at Northwestern Medill. She’s a mass consumer of social media and cares about women’s rights, holistic wellness, and non-stigmatizing reproductive care. As a former collegiate pole vaulter, she has a love for all things fitness and is currently obsessed with Peloton Tread workouts and hot yoga.