Hey Jared, what are your thoughts on Intermittent Fasting for weight loss? What are the benefits and results? Should I try it? If so, how long should I fast? Should I do it every day or only specific days throughout the week?

I’ve been meaning to do a blog post on Intermittent Fasting for while, so this is the perfect opportunity to get my thoughts down for anyone interested in trying it.

What is Intermittent Fasting?

For those that aren’t familiar with Intermittent Fasting, it’s a type of dieting with a specified period of fasting followed by a period of eating. We do a shorter version of this every day: fasting during sleep, and eating during the day. That’s why it’s called ‘breakfast.’ 

Intermittent Fasting takes this a step further and increases the length of the fast, shortening the eating window. Typically the schedule is 16 hours of fasting, followed by 8 hours of eating. The first 8 hours are typically while you’re asleep, followed by the first 8 hours you're awake. This is also known as the 16:8 diet because of the fasting periods. 

Generally, Intermittent Fasting is known for fat loss. There are a few other lesser known benefits that are promoted as well, and I’ll address those a little later. For right now, I want to focus on the fat loss benefits of Intermittent Fasting.

I’ve had some experience with Intermittent Fasting myself, and used it with a few of my clients. This goes all the way back to my first time experimenting with it from 2011 near the end of my diet for one of my shows. 

Let’s just dig right in, shall we?

How does Intermittent Fasting Work?

Intermittent Fasting is not the magic that it is touted to be, but it does have some legitimate benefits and usefulness. While it is best known for being superior for weight loss, there’s nothing incredibly superior about it.

What the Intermittent Fasting diet does is shorten your eating window to a point where caloric intake is naturally restricted. In a normal day to day environment you may eat at least three meals a day along with some snacks, Intermittent Fasting removes the ability to snack between meals and shortens the eating window making it difficult to eat as much food.

Ultimately the only way you’re losing fat with Intermittent Fasting is through caloric restriction, or eating less than you utilize for energy, but that doesn’t mean it’s not superior in other ways. Every single diet is successful in exactly the same way: limiting the amount of energy we consume each day (calories) causing our body to utilize stored fat as the substitute energy source.

While there is nothing ‘superior’ about the fat loss abilities of Intermittent Fasting, that doesn’t mean it doesn’t work. Intermittent Fasting is a great choice for *some* people, and for those people it can be an absolute godsend. On the opposite hand, if your schedule or personality is not optimal for Intermittent Fasting you are likely to be continuously frustrated by this diet.

Awareness

The fasting window will make you incredibly aware of what you are eating throughout the day, which is a defining problem for most unsuccessful dieters. We tend to forget about the ‘little’ things we have throughout the day. The drinks, snacks, bites, or even mints. Everything adds up even if it seems innocent and inconsequential.

By utilizing the fasting window you will be able to see what you are truly consuming and how it may be affecting your progress. The absolute restriction that is associated with the fasting window not only illuminates what you’re eating (which can help long-term with future diets), but also eliminates ‘the little things’ allowing for better success and adherence.

Meal Timing

If you’re rarely hungry in the mornings or always on-the-run you may find the diet easy to follow and helpful to your lifestyle. Contrary to popular belief, breakfast is not required and is not what fuels your entire day. Typically the food eaten the day before will fuel you as well as stored energy reserves (fat) you are hoping to tap into. If Intermittent Fasting seems like it would simplify your life, give it a shot.

Fullness

You may find that many diets leave you feeling unsatisfied. That is because you are spreading small amounts of food over a long period of time, typically upwards of 16 hours per day. If your total daily caloric intake is 1600 calories and you’re spreading that over four meals you may find those meals leave you feeling hungry and never ‘full.’

In contrast, Intermittent Fasting has such a short period of eating that the meals have to be less frequent and larger. Instead of four meals at 400 calories, you would likely eat two meals at 800 calories. Each meal being substantially larger would allow you feel the ‘fullness’ you desire. If you need this sensation of ‘fullness’ during a diet, Intermittent Fasting would be a good choice.

Other Benefits

The benefits from Intermittent Fasting do not stop there. Many notice an increased focus and productivity in the fasting window (after getting used to it). There seems to be some benefits to cellular reproduction and cleansing (autophagy) but the time period required for induction isn’t terribly clear. My thoughts are that longer-term fasts are required for the full benefits (more on this later). 

Digestion

Lastly, the ‘break’ from digesting food can be great for your digestive system. If you eat when you wake up till you go to sleep you’re not giving your digestive system much of a break throughout the day. Allowing your digestive system to ‘relax’ over a period of time can reduce intestinal inflammation and improve gastric motility. If you’ve been having stomach issues, starting with a fast may be a good way to go.

While there are a lot of benefits, there are also a lot of negatives and downfalls to Intermittent Fasting that you need to be aware of. Intermittent Fasting is far from a perfect approach for everyone.

Adaptation Issues

The Intermittent Fasting schedule of 16 hours fasting and 8 hours feeding is not always an easy adaptation. It takes time to adapt to the new schedule, especially if you’re used to eating in the mornings. You may find yourself focusing on your hunger, the inability to eat when you want to, and looking at the clock waiting for your ‘feeding’ window to start. That’s normal in the beginning for nearly everyone and takes some dedication to power through.

Over time things like your hunger hormone are trained to know that you won’t be eating in the mornings and you’ll be reminded when it is time to eat rather than watching the clock for it.

Workout Timing

If you tend to enjoy working out in the morning before starting your day, you will have a little more trouble implementing Intermittent Fasting. Generally there are nutrients we should be taking in around our workout that will have to wait till your feeding window. If you workout at 6am but your feeding window doesn’t start until 2pm, you’re going to have a much harder time recovering from that workout and maintaining energy levels throughout the day.

In my experience Intermittent Fasting fits the person that works out much closer to their feeding time. This doesn’t mean it can’t be done, but for the benefits of Intermittent Fasting and proper recovery around workouts it would be best to have the workout nearby a feeding window.

Over-eating

If you’re not careful you can train yourself to begin over eating with Intermittent Fasting. This occurs because you’re delaying your eating for so long and your stomach is small. At the time when you eat, your stomach begins expanding and should ‘fill’ quite quickly. This is one of the reasons that Intermittent Fasting helps with caloric control. For some, the meals needed to fit into an 8 hour window are so large they will go beyond a normal ‘fullness’ sensation and lead to over-eating issues in the long run.

You may find that due to severe restriction throughout the day combined with caloric restriction (which naturally increases our hunger via the relationship between leptin and ghrelin) that you over-eat frequently when you intend on dieting. Over time this over-eating becomes more of a habit and routine even after stopping the diet which can lead to overeating in future meals.

Overall this is an easy problem to solve with pre-planned meals and proper restriction, but it does take some long-term willpower to develop a new habit loop around eating.

Social Life

It’s possible your social life will not fit into your Intermittent Fasting protocol, and that can cause an issue with adherence over time. Breakfast, Brunch, and Lunches may be something you struggle with for quite some time. Even late night dinners can serve to be a problem.

You can choose to ‘move’ your feeding window earlier to make up for this, or extend your window. If socializing with friends over food is a big part of your life, you may find that Intermittent Fasting is not the way to go. 

It’s Still A Diet

So here’s the nitty gritty of it all. Intermittent Fasting still has the same requirements as other diets for it to be successful. Yes, it has its benefits for some and it can make some of the diet more enjoyable - but it’s still a diet. That means caloric restriction (eating less than you burn each day) is the most important thing to pay attention to. It also means finding ways to increase your metabolic rate (weight lifting) and wasting calories (cardio) to tip the scales of calories in vs calories out in your favor.

Longer Fasts Are Better

If your interest in Intermittent Fasting is leaning more towards the other health benefits like autophagy, digestive health, increased insulin sensitivity, etc. you may consider an alternative approach of a 24-36 hour fast weekly or bi-weekly instead. The benefits of fasting in all of these areas appear to peak around the 36 hour mark. While not traditional ‘caloric restriction’, fasting for 36 hours would reduce calories for the week by around 20% by itself. That 20% reduction would be equivalent to reducing calories from 2000 to 1600 calories on a daily basis.

If after reading everything here you think that Intermittent Fasting would be a good approach for you, try it out! First, make a commitment to yourself that you’re going to stick with it long term - but do it reasonably. Build up to your fasting window over time, plan your meals, and exercise! If you’re going to do it, do it right and commit to it so you really know how well it worked for you.