What is Intermittent Fasting?
Intermittent fasting (IF) is a pattern of eating in which a person alternates between periods of eating and fasting. In this post, we’ll review the basics of IF, including if it works, the different methods, and how our nutrition coaches apply IF at MacroLab.
Does Intermittent Fasting Work?
First, let’s clarify one thing! It’s not intermittent fasting that causes weight loss; being in a caloric deficit causes weight loss.
Research has shown the benefits of IF to include; weight loss, lower blood pressure, and improved gut and metabolic health. IF can work for weight loss because as you condense meals into a shorter timeframe, or don’t eat for an extended period, you tend to eat less. Also, while you are fasting, your body does not have the luxury of using the energy from recently consumed food and must tap glycogen and fat stores for energy.
It’s important to note that there is not much research regarding the long-term outcomes of IF.
Intermittent Fasting Methods
In this option, you have set fasting and eating windows. For example, you fast for 16 hours of the day and only eat for eight hours of the day.
This method is popular because half of the fast happens while you sleep. It’s convenient as you extend the overnight fast by skipping breakfast and not eating until lunch. Here are some of the most common windows.
16/8 method: Only eating between 11 am and 7 pm or Noon and 8 pm.
14/10 method: Only eating between 10 am and 8 pm.
Finding the right eating and fasting windows for these methods might take a few days to figure out, especially if you are very active or wake up hungry for breakfast.
Twice-a-week method – 5:2
This approach to IF focuses on capping your calories at 500 for two days a week. During the other five days of the week, you maintain a healthy and normal diet.
On fasting days, the approach usually includes two 250 calorie meals. You will want to consume high-fiber, high-protein foods to keep calories low while keeping you full on these days.
You can choose whichever two fasting days as long as there is a non-fasting day between them. Be sure to eat your regular amount of food on non-fasting days.
Alternate day fasting
This variation involves fasting every other day. For instance, limit your calories on fasting days to 500 ― or about 25% of your normal intake. On non-fasting days, resume your regular, healthy diet. (There are also other variations to this approach that include consuming 0 calories on alternate days instead of 500.)
The 24-hour fast (eat: stop: eat method)
This method involves fasting for a full 24 hours once or twice a week. Most people fast from breakfast to breakfast or lunch to lunch. With this version of IF, the side effects can be extreme, such as fatigue, headaches, irritability, hunger, and low energy.
If you follow this method, you should return to a normal, healthy diet on your non-fasting days.
What Intermittent Fasting Isn’t
Whether you are doing IF, Carnivor, Keto, Paleo, low carb, high protein, vegetarian – you name it – it all comes down to calories-in versus calories-out. If you are doing IF and in a surplus, you will gain weight.
Additionally, sustainability is a concern as time restricting eating is not for everyone. Some research even shows that those who do intermittent fasting don’t usually stick with it as compared with those on more traditional diets.
Side Effects & Risks
Intermittent fasting is not safe for some people, including pregnant women, children, people at risk for hypoglycemia, or people with certain chronic diseases. Following an IF protocol can cause side effects such as irritability, low energy, hunger, and temperature sensitivity.
Our Take on Intermittent Fasting
Again, it’s not intermittent fasting that causes weight loss; being in a caloric deficit causes weight loss.
That said, we view IF as a tool. For example, if we have a client looking to lose weight who doesn’t like to eat breakfast and works out in the afternoon, we might implement IF. Why? Because it aligns with the client’s preferences of not wanting to eat breakfast and helps to fuel their afternoon workout. Additionally, this client will probably feel more satiated while in a deficit because the feeding window is shorter.
At MacroLab, we have experienced nutrition coaches with a passion for educating our clients. If you have any questions about intermittent fasting or nutrition in general, feel free to contact us.