Intermittent fasting (or IF for short) has become a buzzy type of diet because it’s not like other plans that restrict, say, carbs or fat. And there’s some evidence that it could help you lose weight and reduce the risk of heart disease and diabetes. It seems to check a lot of boxes, which is why you’re probably still reading this article right now. But if you want to know how effective and sustainable IF really is, you’re going to need to stick with us for a couple more minutes.
Intermittent fasting is a strategy to reduce your overall calorie intake by switching between periods of fasting and those when you are free to have meals and snacks. There are several different types of IF. The most common ones are time-restricted eating, the 5:2 diet, and alternate-day fasting. Time-restricted eating is when any food you have is eaten within a specific timeframe—say, 6 to 8 hours each day. With the 5:2 diet, you follow a normal diet for five days and restrict your calorie intake to around 500 to 600 for the remaining two days. Alternate-day fasting is exactly what it sounds like: You eat regular meals and snacks one day and then have minimal to no calories the next day—and so on.
Research shows that intermittent fasting may lead (at least in the short-term) to a drop of more than 5 percent in total body weight among those who have obesity, according to a 2021 review published in the Annual Review of Nutrition. The same study found that all three types of IF mentioned above also reduced blood pressure, fasting insulin, and insulin resistance. Alternate-day fasting and the 5:2 diet were shown to lower LDL cholesterol and triglycerides, while time-restricted eating was associated with reduced oxidative stress.
It’s not clear whether one type of intermittent fasting is more effective than another. If we can give you one piece of advice, it’s this: There isn’t enough evidence to recommend a specific fasting diet. It could help you drop pounds and see other health improvements initially, but IF can be hard to stick to and may not deliver the sustainable results you’re looking for. (You’ve probably been down this fad-diet road more than once and know what we mean.) A recent study published in the Journal of the American Heart Association that had participants track the timing of their meals over a six-month period (and reviewed health records for up to 10 years prior) found that IF didn’t help with lasting weight loss.
Plus, there’s evidence that restricting calories can increase levels of cortisol, the stress hormone. How? When you skip meals, your body senses it as a danger to your body—it’s an age-old, hard-wired starvation signal. Over time, elevated cortisol levels have been linked to weight gain. And on top of that bit of ingrained biology, when you skip meals, you might go a little overboard when you do have a meal. Makes sense; you’re famished!
That’s up to you and your doctor to decide. You should always speak with a physician before trying a new diet. IF is not right for everyone—particularly people with a history of eating disorders, a need to take medication with food at a specific time, and those who are pregnant or breastfeeding, are living with diabetes, blood sugar problems, or sarcopenia (age-related muscle loss). It’s also important to have regular, balanced meals that include plenty of whole foods during the eating window.
Here at Found, we know that weight is more complex than calories in, calories out. And let’s be real–any type of restriction to our eating habits can be difficult to commit to and stay consistent with. At Found, we ditch the dieting and calorie counting trend and instead encourage members to eat whole foods, practice mindful eating, and focus on portion control. Our comprehensive, science-backed approach to weight care considers factors like sleep, stress, and biology—all of which influence your weight. And, weight care isn’t a one-size fits all approach. We offer prescription weight loss medications and a virtual, supportive community in the Found app where members can track their healthy habits and meet their weight care goals. Well, hello, sustainable weight loss.
Found is among the largest medically-supported weight care clinics in the country, serving nearly 200,000 members to date. To start your journey with Found, take our quiz.