Does Intermittent Fasting Help With Your Weight? What You Should Know

Have you ever wondered, “Does intermittent fasting help you lose weight?” The answer isn’t so black-and-white. Fasting means you aren’t eating for an extended period of time. Intermittent fasting is a simple eating pattern that makes the most of your body’s own fat-burning systems. Research shows that intermittent fasting is a proven way to help people stay at a healthy weight.^[1]

There are lots of different approaches to weight loss—but we’re here to talk about weight management, which means adopting lifestyle modifications to stay at a healthy weight. Think of intermittent fasting as a tool to add to your wellness toolkit. Read on for the science behind intermittent fasting and weight management, plus tips to maximize your fast.

How weight management works with intermittent fasting

When you’re intermittent fasting, you eat all the food your body needs, but during a shorter period of time. There are many methods, but the most common involves eating during a six- to eight-hour window and fasting the remaining 14 to 16 hours. It’s not as bad as it sounds, especially when you fuel up beforehand with Bulletproof Coffee to keep hunger levels in check.

Multiple studies show that intermittent fasting supports weight management. In a 2015 review pooling 40 different studies, participants lost 10 pounds in a 10-week period on average.^[2] Another smaller study of 16 obese adults following an “alternate day” intermittent fasting schedule (eating 25 percent of their daily calories on one day, and eating normally the following day) resulted in them losing up to 13 pounds over 8 weeks.^[3]

Intermittent fasting also triggers a perfect storm of metabolic changes to tackle weight management and fat reduction. Here’s how it can help you stay at a healthy weight:

Reduces calorie intake

If you’re a snacker or tend to grab food on the go, you may be eating more calories than your body needs—and an excessive caloric intake will show up on the scale over time. In general, you tend to eat fewer calories when you limit the amount of time you have to eat during the day.

Kickstarts ketosis

Intermittent fasting is a pathway to the fat-burning state of ketosis. During your fasting period, your body burns through its glucose reserves (aka carbohydrates) for energy. When you remain in a fasted period, you eventually start burning dietary fat and body fat for fuel. To stay in ketosis, eat a ketogenic diet between periods of fasting.^[4]

Lowers insulin levels

Intermittent fasting affects insulin in two ways. First, your body becomes more sensitive to insulin, which can help prevent weight gain and reduce your risk of diabetes. Second, fasting decreases your insulin levels, which can cue your body to start burning stored fat instead of glucose.^[5]

Boosts metabolism

In rodent studies, intermittent fasting reprogrammed metabolic pathways to get more energy out of food.^[6] Fasting has  also been shown to increase levels of adrenaline and noradrenaline. These hormones help your body use stored energy (that’s your body fat) during a fast.^[7][8] Boosting your metabolism helps your body burn more calories throughout the day, even while you rest.

Targets visceral fat

Intermittent fasting also succeeds where many weight management regimes fail: by targeting and reducing visceral fat. Visceral fat is the stubborn, internal fat packed deep around your abdominal organs. During a period of six months, people on an intermittent fasting diet were able to shed four to seven percent of their visceral fat.^[9][10]

Reduces inflammation

Intermittent fasting decreases oxidative stress and inflammation across the board, including inflammatory markers such as adiponectin, leptin and brain-derived neurotrophic factor (BDNF).^[11]

According to early research (read: rodent studies and small human sample sizes), lowering inflammation may be the key to maintaining a healthy body weight, boosting longevity and reducing your risk of major illnesses.^{[12] [13] [14]}

Additional health benefits of intermittent fasting

Intermittent fasting isn’t just about achieving a healthy weight. Here are some additional benefits you’ll experience along the way:

• Improves cardiovascular health: Intermittent fasting diets have been shown to improve cholesterol, improve blood pressure and reduce cardiovascular risk.^[15][16] One note: These studies associate intermittent fasting with lower levels of LDL and VLDL cholesterol, but managing your inflammation might be more important.
• Helps remove cellular waste: Over time, your cells naturally accumulate damaged cells and waste—junk that can interfere with cellular function. In rodent studies, intermittent fasting has been shown to promote a process called autophagy, which is what happens when your body clears out the cellular junk so your body can work even better.^{[17] [18]}
• Supports healthy aging: Studies show that intermittent fasting can help protect your cardiovascular system and how you manage blood sugar to support healthy aging. In rodent studies, intermittent fasting has been shown to increase lifespan and protect against disease.^{[19] [20]} Worried about the long-term effects of stress? Fasting has been shown to promote feelings of tranquility and alertness.^{[21] [22] [23]}

How to start intermittent fasting

There is more than one way to start intermittent fasting, which is great because everybody is different. The key is to experiment and listen to your body to see what works best for you.

Here are some of ways to get started:

• 16:8: You eat all of your daily calories within a shortened period (typically a 6-8 hour period) and fast the rest of the time.
• One meal a day (OMAD): Also known as eating once a day. You eat all of your daily calories in just one meal each day, and fast the rest of the day.
• 5:2: You eat normally five days a week. On the other two days, you “fast” by eating between 500 and 600 calories.
• Alternate Day Fasting: You alternate fasting on certain days of the week: a day of eating normally, followed by a day eating 25% of your typical daily calories. A study found that obese adults following an “alternate day” intermittent fasting schedule lost up to 13 pounds over 8 weeks.^[24]

If intermittent fasting causes fatigue or other negative side effects, try fasting just once or twice a week, and build up from there.

As with any diet or exercise plan, consult your healthcare provider or dietitian to determine what’s best for you. If you struggle with healthy eating patterns or dieting behaviors, intermittent fasting may not be for you—and that’s totally okay. There are many different ways to live a healthy lifestyle. Intermittent fasting is just one style of eating that works for some people, and doesn’t work for others.

Related: Want to Try a Fasting Diet? How to Choose the Right One

Tips for intermittent fasting for weight management

No matter what intermittent fasting plan you follow, you can expect to deal with an adjustment period—especially if you’re used to extended eating periods that include multiple meals and snacks. Here are some tips to help manage cravings and power through your fast. Broadly speaking, follow a healthy diet during your eating periods, and consider tracking your food intake to make sure you’re hitting your caloric and macronutrient targets.

Eat the right fats

To get more available energy in your body before you start your fast, Bulletproof Brain Octane C8 MCT Oil. Your body turns MCTs into ketones, which help burn fat, curb cravings and power your brain with more energy for better mental performance.^{[25] [26] [27]}

Not sure how to use MCT oil? It’s great in Bulletproof Coffee, but it’s also an easy add-in to smoothies, salad dressings and dips like this guacamole recipe. And who doesn’t love all the healthy fats from avocados in a good guac recipe?

Cut back on carbs

To supercharge the benefits of intermittent fasting, cut back on the carbs (like whole grains, starches and sugars) during your eating window. Eating more quality fats and restricting carbohydrates will decrease your appetite (bye, energy crashes) and make it easier for your body to shift into fat-burning ketosis.

If you’re not ready to go full keto, try a low-carb diet instead—they’re different!

Plan meals ahead of time

When it’s time to eat, those sweets and snacks start looking mighty tempting. To avoid bingeing on carbs or junk food, prepare healthy foods ahead of time with the right fats, high-quality meats and plenty of vegetables. These keto meal prep recipes will help you stay on track.

This article has been updated with new content.