Intermittent fasting is one of the few diets with some hard science behind its claims of boosting health and longevity. While the evidence base remains small and much of the research is in mice rather than humans, studies have shown how intermittent fasting could help prevent metabolic conditions, safeguard brain health, and even stave off the ill-affects of aging (it does not, however, seem to cause people to lose weight, according to one randomized clinical trial).
Just as intermittent fasting has risen in popularity, becoming the darling of celebrities, influencers, and the bodybuilding world, intuitive eating, too, has garnered the attention and praise of nutritionists as preferable to other dietary trends, like keto.
What if there was a third way, a way to combine the benefits of both food plans and reap the rewards?
Enter intuitive fasting.
What is intuitive fasting?
Intuitive fasting is like intermittent fasting, in that you eat during certain windows and fast during others. But unlike intermittent fasting, the intuitive piece refers to developing the attention and awareness of your own body necessary to decide how to organize eating and fasting in a way that works for you personally.
Dietician Evelyn Tribole and nutrition therapist Elyse Resch developed the concept of "intuitive eating" in the 1990s in response to what they perceive as dangerous and ineffective restrictive diet trends. In their book, Intuitive Eating: A Revolutionary Program That Works, they promote listening to bodily cues to know when, what, and how much to eat. Calories are irrelevant, you eat until you feel full. You should eat when you feel hungry, and instead of condemning certain foods as "bad," you eat what you want with an emphasis on respecting your body.
Intuitive fasting seems to embrace similar ideas, but with the added incorporation of intermittent fasting and the health benefits it brings.
Who coined the term 'intuitive fasting?'
The term "intuitive fasting" was coined by functional medicine expert Will Cole. Cole is not an MD, and instead bills himself on his website as having had postgraduate training in functional medicine and natural medicine.
Cole says he developed the concept after years of experience in his functional medicine practice.
“I wanted to eliminate the strict dogma that can sometimes be associated with intermittent fasting"
“I wanted to eliminate the strict dogma that can sometimes be associated with intermittent fasting and bring in concepts from intuitive eating that allows a person to really lean into what works best for them during different periods of their life,” Cole tells Inverse.
What benefits does intuitive fasting have for your health?
Intuitive fasting is meant to yield the same purported benefits of intermittent fasting, except a person learns new skills and strategies to adapt intermittent fasting to their own personal needs and rhythms.
John Hopkins Medicine lists the potential benefits of intermittent fasting as including:
- Improvements in thinking and memory
- Improvements in blood pressure, resting heart rate, and other cardiovascular metrics
- Better endurance
- Prevention of diabetes
- Reduced tissue damage during surgery
“The goal of intuitive fasting is to help you understand where your body feels best, eliminate insatiable cravings, and end mindless eating,” Cole says.
“A lot of us are on a blood-sugar rollercoaster, held captive by 'hangryness' and our cravings.
“A lot of us are on a blood-sugar rollercoaster, held captive by 'hangryness' and our cravings.”
What is the science behind intuitive fasting?
Inverse has previously reported on fasting studies conducted on mice which found that "alternate day fasting" resulted in:
- Improved liver protein profiles and fatty acid metabolism
- Improved insulin sensitivity
- Increased lifespan
- Reduced fasting-glucose levels
- Decreased total blood cholesterol levels
- Increased lifespan
- Prevention of cardiovascular disease, dementia, cancer, and diabetes
Though intermittent fasting gets a lot of attention as a weight loss strategy, a recent study in humans found that it did not result in significant weight loss. However, some practitioners emphasize that their goals revolve around health and longevity, not body size.
Studies of intuitive eating also boast a constellation of positive effects, mainly related to psychological health. Inverse has previously reported that intuitive eating has been found to:
- Increase emotional functioning in women
- Increase positive body image in women
- Reduce disordered eating, such as binge eating and emotional eating
- Increase self-esteem
- Reduce weight fluctuation
Is intuitive fasting better than intermittent fasting?
One criticism of proscriptive diets, including intermittent fasting, is they may provoke or exacerbate eating disorders in susceptible populations. Inverse has previously reported Tribole called intermittent fasting a "gateway to an eating disorder," expressing concern that ignoring hunger cues to align with an eating window can be psychologically dangerous.
By marrying intuitive eating with intermittent fasting, intuitive fasting could potentially help mitigate some of the safety concerns associated with intermittent fasting by helping to cultivate a practice of being in touch with bodily cues and selecting a fasting regimen that feels healthy for you.
Cole says that because of intuitive fasting is flexible and easy to personalize, he believes it may be more sustainable.
“So you can reap the many health benefits long term,” Cole says.
Sustainability may be key, as 'dieting' efforts in general are famous for being short-lived.
Further, many experts express concern about the safety of yo-yo dieting, which is when a person diets for awhile in a non-sustainable way, and then finally gives in, returning to their previous diet. Some studies have shown that the weight gains and losses associated with yo-yo dieting, called "weight cycling," is associated with increased depressive symptoms and higher risk of death from heart disease.
Although, it is worth mentioning other studies have had different results.
Regardless of whether yo-yo dieting is bad for you in the long term, being able to stick to a diet that is working well for you is obviously ideal.
Cole says fasting “has been shown to help to lower inflammation, improve brain function, [and] increase metabolism as well as increase longevity and anti-aging pathways.”
How long does intuitive fasting take to work?
Cole says this depends on your individual needs and goals.
His book outlines an intuitive fasting plan that he says should make a difference after four weeks and can be repeated thereafter in accordance with an individual’s needs. So you are looking at at least one month of commitment before you see a difference, it seems.
How do I intuitively fast?
Cole says his book lays this out in detail, but in short, his process involves exploring a new eating and fasting window each week, for four weeks.
Throughout the process, he says, you learn to develop your own intuition about what about what your body needs. This way, you can change your fasting habits as necessary. For instance, if you start a new exercise regime, you may want to alter your eating habits to include more healthy carbs or a different fasting window.
In traditional intermittent fasting, there are several eating window options that different people utilize:
- 5:2 - Eating normally for five days and then eating roughly 25% of your regular calories for two days
- 18:6 - Fasting for 18 hours and eating during a 6 hour window every 24 hours
- 14:10 - Fasting for 14 hours and eating during a 10 hour window every 24 hours
- Complete fast on certain days of the week
We don't yet know if Cole is riffing on these traditional windows for intuitive fasting, or if he's come up with a totally novel approach.
Cole’s upcoming book on the subject, Intuitive Fasting: The Flexible Four-Week Intermittent Fasting Plan to Recharge Your Metabolism and Renew Your Health, is scheduled for release in February 2021.