What is Intermittent Fasting?
What is intermittent fasting? Intermittent fasting is an eating style that has grown in popularity over the past few years. Rather than focusing on what you can or can’t eat, intermittent fasting focuses on when you can or can’t eat. Think of it as meal timing vs. meal planning. Given the focus on meal timing, intermittent fasting is less of a diet and more of a pattern of eating. At its core, intermittent fasting alternates periods of eating with periods of fasting. The goal of intermittent fasting is to harness the benefits associated with fasting and allow followers a more black and white approach to losing weight. Although at the surface intermittent fasting my sound clear cut and simple. There are many specifics to consider when determining if it’s right for you. First this to consider is the timing of fasts that you choose. Within Intermittent fasting, there are many different eating schedules you can follow:
Intermittent Fasting schedules
- Daily fasting: 16:8, a 16-hour fast followed by an 8-hour eating window. 20:4, a 20-hour fast followed by a 4-hour eating window
- Alternate day fasting: With this approach, people typically go 24 to 36 hours without food, then eat up to two days worth of calories over the course of 12 to 24 hours
- Multiple day fasting: In this type of fast, people might choose to go several days without food. It’s typically only used in clinical settings to treat or manage certain medical conditions
Daily fasting is the most common form of fasting for weight loss is daily intermittent fasting. This style of fasting breaks up each day into two windows: fasting and eating. During the fasting window, people may go without food for anywhere from 12 to 23 hours. During the eating window, people will eat their daily allotted calories, typically distributed among 1-3 meals. One of the most common approaches to daily fasting is known as the 16:8, which involves a 16-hour fast, followed by an 8-hour eating window. For example, someone might eat their first meal at 12:00pm, stop eating by 8:00pm, and fast overnight until noon the next day. A more extreme, but also common approach is the 20:4, where someone might eat their first meal of the day at 2:00pm, for example, in which case they’d finish eating by 6:00pm that day.
Alternate day fasting
Alternate day intermittent fasting is another type of fasting where people eat every other day. With this approach, people typically go 24 to 36 hours without food (these are called fasting days), then eat up to two days worth of calories over the course of 12 to 24 hours. Although extreme, some people try to use this as a weight loss strategy. The fasting days and eating days may make it easier for followers to know when to eat their calories.
The sheer volume of food that must be consumed to get adequate calories in this style of fasting can become challenging for followers of alternate day fasting.
Multiple day fasting
Multiple day fasting is the most extreme type of fasting. On this schedule, people might choose to go several days without food. In general, this is only used in clinical settings to treat or manage certain medical conditions and is monitored closely by a medical team, meaning it’s never usually recommended for the average person looking to lose weight.
Intermittent Fasting benefits
- Increased energy, focus, and mental clarity
- More satisfying meals (since you’re usually eating fewer, larger meals)
- Body fat loss
- Weight loss
- Improved biomarkers, like cholesterol and blood sugar levels
When diving into the benefits of intermittent fasting, it’s important to note that the majority of studies done on intermittent fasting have been in mice.
Despite the lack of human research, there are many people who follow this style of eating and have found success with it.
Although these benefits sound promising for those looking to lose weight, a lot of this “evidence” is self-reported and anecdotal — which is not always the best predictor for how successful something is. Another factor to consider is that many of these benefits are difficult to measure. It’s hard to really measure what it means to have “more energy,” and whether or not this “benefit” is actually just a placebo. Hey, we’re all for a good placebo effect — if it works, it works.
Another benefit to consider is that intermittent fasting can be easier for those individuals who struggle at meal planning and prepping. Since you are eating fewer times per day, this schedule can simplify your day and the time spent cooking, shopping or preparing meals. Although you will still have to ensure you have adequate nutrition when eating your meals, fewer meals just equates to overall less time you have to dedicate to eating and preparing those meals. At the end of the day the research on human intermittent fasting is young and we don’t really understand the potential long-term impact. For that reason, caution should be used when starting scheduled eating such as this.
What to eat during Intermittent Fasting
As mentioned earlier, intermittent fasting focuses more on the timing of food instead of the choices of food. Through a shorter time period of eating, calories can be reduced more easily and followers are able to continue eating the foods they enjoy, while losing weight. It could be said that fasting of any kind is a form of calorie restriction as no food is being consumed. On the flipside, unlike diets such as Keto or Atkins, food choices are typically not restricted and followers can develop a balanced approach to food choices for their eating windows.
To ensure success on any intermittent fasting plan, food choices should be balanced and overall calorie balance should be considered. If too many calories are consumed during the eating window, weight gain can still occur. Like any other plan, success or failure always comes back to balance.
Interested to see what a week of eating on intermittent fasting might look like? Check out the sample plan below!
Intermittent Fasting guide
- Noon: Pasta with spinach, chicken, and tomato sauce
- 3pm: Avocado toast
- By 8pm: Cobb salad with chicken
- Noon: Salmon or tofu with sweet potatoes and asparagus
- 3pm: Banana ice cream topped with chocolate chips
- By 8pm: Potato soup and a side salad
- Noon: Hard boiled eggs, pita, veggies, and hummus
- 3pm: Apple slices with almond butter
- By 8pm: Big green salad with chicken, avocado, almonds, and lemon dressing
- Noon: Broccoli soup, bread, and a side salad
- 3pm: Smoothie with banana, cashew butter, spinach, and almond milk
- By 8pm: Vegetable and shrimp/chicken stir fry
- Noon: Gnocchi with pesto and a side salad
- 3pm: Dried mango and almonds
- By 8pm: Fish tacos
- Noon: Mixed veggies, chicken or tofu, and rice topped with soy sauce and sriracha
- 3pm: Trail mix
- By 8pm: Beef or seitan steak with steamed broccoli and roasted potatoes
- Noon: Chickpea salad with lemon dressing and a green smoothie
- 3pm: Dark chocolate
- By 8pm: Spaghetti with meatballs or lentil sauce and a side salad
Is Intermittent Fasting healthy?
Although research in animals suggests that there may be some benefits associated with intermittent fasting, benefits alone do not represent the health of a diet. Sure, in the short-term, intermittent fasting might help most people lose weight. But in the long term, fasting can be difficult both mentally and physically.
Think about having to plan social gatherings or date nights out around your eating window. Not to mention that if calories and micronutrients aren’t properly met, your body can produce increased levels of cortisol, which is a stress hormone that has been tied to increased body fat storage and the breakdown of muscle.
This isn’t to say that anyone who follows an intermittent fasting schedule will have increased cortisol levels but that fasting long durations of time does cause stress to multiple systems of the body. If not approached in a balanced and mindful way, this can have negative health outcomes including decreased sleep quality and increased irritability.
Intermittent Fasting results
Just like any diet, results from intermittent fasting vary and are not guaranteed. It’s important to remember that intermittent fasting has the same downside as every other diet: It only works as long as you can stick to it. Eventually, when you give up the diet, you’ll probably gain back the weight you lost – and lose whatever other benefits the diet offered.
This is where Noom can help. If you want to try out intermittent fasting or any eating style for that matter, we at Noom can give you the coaching, community support, and recipe ideas that make it possible. We’ll also help you explore whether this is a sustainable option for you.
With Noom, you’re never limited by rigid plans or strict diets. Our team of nutrition and psychology experts can help you find sustainable, long-term solutions that are flexible enough to meet your lifestyle while still delivering the incredible health benefits you’re looking for. Sign up for a 14-day trial and see what Noom is all about!