Jennifer Aniston Says She Noticed a "Big Difference" When Following This Diet (2024)

One eating pattern focused on weight loss is intermittent fasting, where you alternate fasting and eating on certain days or during certain hours. There are many different types of intermittent fasting. Fasting for 16 hours and eating during an eight-hour window is known as 16/8 intermittent fasting.

In a 2019 interview with UK magazine Radio Times during the promo trail for her Apple TV+ show, "The Morning Show," Jennifer Aniston revealed she was a big fan of 16/8 intermittent fasting. "I do intermittent fasting, so no food in the morning. I noticed a big difference in going without solid food for 16 hours," said Aniston. Here's what else you need to know about this type of fasting, including benefits, risks, and more.

Fasting for at least 12 hours—as you would with the 16/8 intermittent fast—affects how your body metabolizes food and drinks. Usually, your body is energized by glucose, a sugar that comes from what you eat and drink.

Every time you fast, you may have less glucose from a decreased food or drink intake. Your body will look to any fat in the body to use for energy. Your body will then use ketones, a chemical produced from fatty acids, as the primary energy source instead of glucose.

How To Do It

When you do a 16/8 intermittent fast, choose your eating schedule based on a 16-hour fasting window and an eight-hour eating window. You should determine an eating window that fits with your routine, but make sure it's the same part of the day. Tanya B. Freirich, MS, RD, CDN, New York-based nutritionist and registered dietitian, told Health your window should start early in the day, preferably no later than about 10 a.m., and finish early in the evening.

"This allows for the energy you consume during your eating window to serve your activities throughout the day, plus it's in line with our natural circadian rhythms, presuming you wake up around 6 a.m. to 9 a.m.," explained Freirich. If you choose a much later eating window, say 4 p.m. to 12 a.m., you could see weight gain, cautioned Freirich.

What To Eat

During your fasting window, you can have drinks like black coffee, unsweetened tea, and water. These drinks don't have calories.

You don't have to stick to specific foods during your eating window. However, if weight management is your goal, you'll want to opt for some of these foods when it's time to eat:

• Fruits and vegetables
• Healthy fats
• Lean and plant proteins
• Whole grains

It's also a good idea to eat foods high in added sugars or salt in moderation. There's no prescribed calorie limit with 16/8 intermittent fasting, so you don't have to rely on calorie counting guides before eating.

Benefits of Intermittent Fasting

The primary benefit of intermittent fasting most often discussed is weight loss, if that is your goal. One review found that, across 27 studies investigating intermittent fasting, participants experienced a percentage of weight loss from their baseline weight.

The weight loss as a result of intermittent fasting could also play a role in other health benefits, such as:

• Anti-inflammatory effects
• Decreased risks related to heart problems (e.g., due to improved lipid profiles and reduced bad cholesterol)
• Improved glucose regulation and decreased insulin resistance
• Improved arthritis symptoms
  

If you have diabetes, there is a risk of having low blood sugar if you start intermittent fasting. It's also possible that people may not get the nutrients they need during eating windows. That's why it's important to talk with a registered dietitian or healthcare provider if you desire to begin this eating pattern.

Side effects can occur with intermittent fasting. Those side effects may include headaches, low blood pressure, and weakness or fainting. You might also feel grouchy and tired as you get used to your eating schedule. Note that these side effects may last up from two to four weeks.

Other Concerns

It's important to not let intermittent fasting take over your life. "Sometimes people shy away from social events because they interfere with the timing of the fast," New York-based nutritionist Lauren Harris-Pincus, MS, RDN, told Health. "I never recommend letting an eating behavior determine your interaction with friends, family, or coworkers."

Additionally, while combining exercise and intermittent fasting can be helpful, pay attention to when you exercise in relation to fasting. Harris-Pincus warned against exercising while fasting or waiting several hours after exercising to eat your first meal. "You want to feed those muscles and replenish carbohydrate stores after an intense workout," said Harris-Pincus.

If you are at risk of disordered eating or think that fasting could negatively affect your mental health, intermittent fasting is not for you. Speak to a mental health professional when putting together a weight management program.

Who Is It For?

Intermittent fasting can help individuals wishing to lose weight. This type of fasting may also be suitable for people with the following conditions:

• Arthritis
• Cardiovascular disease
• Neurological disorders
• Some cancers

Intermittent fasting comes in a few forms, including 16/8 intermittent fasting where you eat within an 8-hour window but fast for 16 hours. This version of intermittent fasting comes with potential benefits like weight loss and blood sugar regulation.

However, there are side effects such as headaches or weakness and the risk of low blood sugar or not getting enough nutrients when doing intermittent fasting. If you are trying to decide if you want to do intermittent fasting but aren't sure if it's right for you, reach out to a registered dietitian or healthcare provider.