By now you’ve probably heard of intermittent fasting and if you’re like many people I encounter in my private practice and day-to-day life, you’re probably wondering if you can lose weight or age healthier with intermittent fasting. The short answer is yes, you can lose weight intermittent fasting. The long answer isn’t as simple. Let’s dive into the types of intermittent fasting and then you can see if it’s right for you and your needs.
Types of Intermittent Fasting Diets
There are several types of intermittent fasting diets, but here are some of the more popular styles:
16/8 method: This intermittent fasting protocol is also known as a time restricted eating plan. You eat during certain windows (often eight hours during the day) and don’t eat during the other windows (typically the remaining 16 hours).
5:2 method: Followers of this intermittent fasting method eat normally five days out of the week and restrict calories the other two days. On these days, it’s common to consume 500 calories (think: the amount in a smallish, sensible meal).
Alternate Day Fasting: This type of intermittent fasting is pretty straightforward. One day you eat normally, the next day you fast (or do a modified fast, consuming around 500 calories). Then you repeat the protocol.
Prolon: This is a clinically tested fast-mimicking plan. Essentially, you get a kit that contains packaged bars, teas, broth, olives and a few other items that’ll get you through a five-day modified fast. The idea is to “trick” your body into fasting mode by doing this modified version of a fast over the course of five consecutive days. You can repeat this process on various cycles (say, once a month for three consecutive months or every other month).
Can you lose weight intermitting fasting?
Science backs up the fact that intermitting fasting is an effective way to lose weight. The most basic reason is because it puts you in a calorie deficit, meaning you’re probably consuming fewer calories over the course of the week, regardless of the type of fasting protocol you choose. This may sound appealing, however, one study found that intermittent fasting wasn’t any more effective than other forms of calorie restriction (such as a sensible eating plan) that may be easier for some people to sustain. (1)
However, there’s also some evidence that the various types of intermittent fasting methods reprogram some hormones tied to your metabolism, like insulin. (2) Intermittent fasting may also influence your appetite regulating hormones, though this may have more to do with meal timing (when your heaviest meal is eaten, for example), than the act of intermittent fasting itself. (3)
Are there other health benefits to intermittent fasting?
A lot of the hype around intermittent fasting comes from animal research, which is promising but far from conclusive. For example, one animal study found that mice exposed to stress (seriously!) had significant improvements in their inflammatory response when exposed to a type of intermittent fasting protocol. It’s thought that this could translate to improvements in your thinking and memory skills and may preserve your brain functioning over time. (4)
Chronic inflammation influences other disease processes, too, and intermittent fasting might result in lower levels of inflammation and thus, healthier aging. (5) One study among people who followed three cycles of a fasting mimicking diet (the type of intermittent fasting used in the Prolon method) found that the protocol led to improvements in many risk factors for diseases, like cancer, heart disease, and metabolic syndrome. (6) Again, all of this sounds promising, but there are some caveats. For example, the human trials are mostly short-term and in one year-long study, HDL cholesterol levels (the good kind) had gone up at the six-month mark but back down by month 12. At the same time, LDL cholesterol levels (the unhealthy type) were the same at month six, but elevated at month 12. Without knowing what happens down the line, it’s hard to say whether benefits seen in other studies stand up over time. What I’m saying is that when you have improvements in markers for disease at some short-term interval, like 6 months, it doesn’t necessarily give you a picture of what those markers could look like in a year or two or ten.
Who should try intermittent fasting?
If you’re the type of person who likes the structure of intermittent fasting, it might be worth a shot. Some people like the clear and simple guidelines of the different types of intermittent fasting protocols, and following the “rules” can minimize some of the late-night snacking or other eating behaviors that make it difficult to reach a comfortable weight.
But the main thing to think about is whether any type of intermittent fasting is sustainable for you. I know a lot of people who do well with the rigidity of intermittent fasting but just as many who find it difficult to maintain. (Studies back this up, too; there are high dropout rates among people assigned to various types of intermittent fasting methods.)
If you’re thinking about intermittent fasting, here are some questions to ask yourself to determine if it’s right for you.
Can you put up with hunger? Be realistic with yourself. If feelings of hunger make you really distracted and irritable, intermittent fasting will probably be hard for you.
Does your lifestyle involve a lot of socializing around food? If you attend multiple business dinners each week or if you frequently go out with friends, restricting food might be awkward, or worse, your devotion to intermittent fasting might interfere with a full social life.
Do you work out in the morning? One of the main problems I see with intermittent fasting is prolonging your first meal until noon, and this is especially problematic if you’re working out in the morning. Going hours after a workout without refueling interferes with healthy muscle recovery.
Have you ever had a turbulent relationship with food or your weight? If you’ve been a lifelong dieter or have had a history of yo-yo dieting, I would think twice before trying any type of intermittent fasting. It might make you overly (and unnecessarily) restrictive, which can take a toll on your emotional wellbeing. If you have kids at home, this kind of eating pattern for the sake of losing weight can also normalize weight anxiety and restrictive dieting and studies show this influences your child’s relationship to food and body weight.
If you do want to experiment with intermittent fasting, here are a few things I’d recommend:
Try it out on a weekend, when you may be sleeping a little later and naturally restricting the window during which you eat. If you’re sleeping until 8 or 8:30 AM, it’s not that big of a deal to delay eating until 11:30 AM or 12 PM and finish by 8 PM. If it goes well, you can experiment with a weekday, too.
Don’t fall into an all or nothing trap. You may find you can keep it up on weekends but not on weekdays. If you’re benefiting from that routine, that’s fine. If you’re not, that’s also fine. There are a lot of other ways to reach or maintain a comfortable weight and experience better health as you age.
Don’t use intermittent fasting as an excuse to forget about other principles of healthy eating. I’ve met some people who like the guardrails around timing but don’t give consideration to eating well within the eating time frames. It’s still important to lean on the right foods for optimal health.
Regardless of whether you decide to try a type of intermittent fasting, it’s a good idea to go 12 hours between dinner and breakfast. Our bodies aren’t designed for late-night eating and giving yourself some time to digest after dinner (at least two hours is ideal) can also help you sleep better.
Now that you know about the various types of intermittent fasting and the things you need to consider, figure out if it makes sense to you and if it does, feel free to give it a try. If intermittent fasting doesn’t make sense to you, no need to give it a second thought. Most people can achieve better health and reach a more comfortable weight by following these simple rules: Eat mostly whole or minimally processed foods; load up on veggies during lunch and dinner (they’re optional but encouraged at breakfast); cut waaaaay back on heavily processed foods with added sugars and refined grains. That eating pattern along with an enjoyable activity (it doesn’t have to be hard core!) and proper restoration (sufficient sleep and healthy stress management) are really the keys to a healthy weight and life. In fact, several longer-term studies suggest that these are the pillars of living a long, healthy, and happy life.
If you’re tired of figuring out what and how to eat in order to feel better in your body, fit in your clothes more comfortably, and experience more energy and better health as you age, I hope you’ll reach out! I help make healthy eating and living easier, more fun, and more approachable, even when time is tight. Schedule your complimentary call today to learn more!
Want to geek out on the science? Read the references below!