Folks, you know I’m a believer in intermittent fasting for longevity, autophagy, mental clarity, fitness performance, metabolic health, and more. Dr. Jason Fung, a world expert on fasting, has stopped by the blog today to share a bit about fasting for weight loss. Enjoy—and be sure to share any questions you have on the comment board.
Over the years, I’ve shared with you the many ways intermittent fasting can benefit your health. So, it shouldn’t be much of a surprise that fasting can also be really beneficial to those who are trying to lose fat. Yes, I said fat and not weight. Unlike some other kinds of weight-loss methods, which result in loss of water weight or muscle mass, fasting can effectively get rid of fat.
How Fasting Works
There’s a reason intermittent fasting has become so popular. For one, it’s more of a schedule than a diet, which means it’s endlessly customizable. There are a few different types of fasting (covered below), as well as a variety of schedules you can follow. It’s up to you to decide how to make it best fit your lifestyle. (1)
As the name suggests, this method involves eating every other day. On those days, you eat without restriction. On days that involve fasting, you can eat one small meal that provides about 25% of your daily caloric needs. This works great for people who don’t want to face an entire day without eating anything.
Similar to alternate-day fasting, whole-day fasting means you fast 1-2 days per week. You can do a complete fast, with no calories at all, or one small meal that makes up about 25% of your daily caloric intake. A favorite way to do a 24-hr fast is to finish eating at 6 p.m. one day and then not eat until dinner at 6 p.m. the next day. Boom, 24 hours fasted but not a day went by without food.
This method allows a specific time frame during the day during which you can eat regular meals and snacks. A window of 8 a.m. to 3 p.m. is one example of when you can eat, or 12 p.m. to 7 p.m is another. This window of time is usually about 7 or 8 hours long. The rest of the time, you fast.
How Fasting Accelerates Fat Loss
Intermittent fasting almost invariably produces a calorie deficit, but it also creates ideal circumstances for fat burning—because it increases your insulin sensitivity. When you fast, your insulin levels drop, which makes it easier for your body to access your stored fat. That’s how your body opts to use fat for energy, instead of muscle. (2)
You might be familiar with this concept, because it’s the same reason why people adopt low-carb diets to shed fat. Eating low-carb will indeed lower your insulin levels, but the fact is that fasting will drop them even lower. This makes fasting more powerful for fat loss.
Another way fasting boosts fat loss is by increasing the amount of growth hormone (GH) your body produces. Studies have shown that production of GH can decrease your amount of body fat. (3, 4)
Finally, fasting has also been shown to increase production of norepinephrine—the fat burning hormone. The only catch? The study that showed this result was done on mice. Science hasn’t determined yet if it’s also the case with humans.
5 Tips to Accelerate Your Fasting
Intermittent fasting works best if you tailor it to your lifestyle, but there are a few rules you should follow. Here are my top 5 tips to accelerate your fasting for maximum fat loss:
1. Be Smart During Your Eating Window
When you start fasting, it’s easy to just focus on the not-eating part and trick yourself into thinking you can eat anything during your eating window. But if you want to jump-start fat loss, your meals should still be nutritious and healthy. Think no refined carbs, sugar, or processed food. Sticking to a healthy diet is also going to help make the fasting experience easier for your body.
2. Break Your Fast Properly
When you break your fast, it’s very important that you resist the urge to overeat. Over-indulging really defeats the purpose of that calorie deficit you created during the fast. Plus, it can be really uncomfortable for your digestive system and cause a stomach ache or other digestive distress. Try breaking your fast with a small salad or some nuts and then just eat normally.
3. Stay Active & Do Shorter Bursts of Intense Exercise
Don’t fall victim to a mindset that says you should lie around on the couch all day while fasting. It’s perfectly safe (and beneficial) to exercise. Follow your normal routine of walking and other means of slow and steady movement throughout the day. What you might want to skip, however, are long stretches of cardio work that can wear you down (particularly if you’re new to fasting). For intensive exercise while fasting—especially if you want to kick-start fat loss, HIIT is the way to go. You only need 10-15 minutes of high intensity interval training to stimulate fat burn in your body. Above all, work out when you have time and feel comfortable doing it, but you can also consider incorporating your interval training at the end of your fasting window—right before you’re about to break your fast.
4. Use Apple Cider Vinegar
The acetic acid in ACV helps keep your insulin levels low, which means you’ll enter a fat-burning state sooner. There’s also research indicating that ACV can boost ketosis by helping your cells produce more energy when you’re in that state. (5, 6) What that means for you is increased energy and mental clarity to stick with your fasting for longer. Try diluting 1-2tbsp of ACV in a glass of water and drinking it before your meals.
5. Use Green Tea
The number one reason people fail at fasting is because they give in to cravings. So, if you want to succeed at using fasting for fat loss, you need a plan for facing down those cravings. The number one doctor-approved natural way to beat cravings? Tea. Intermittent fasting and tea are a powerful combination for accelerating your weight loss.
Green tea especially has the ability to help regulate ghrelin, which is your hunger hormone, so you can finally gain back control of your appetite. It also boosts thermogenesis, which is the rate at which you burn calories, and it has the ability to enhance autophagy, your natural cellular renewal process.