Intuitive fasting means that you refrain from eating until you’re really hungry and then eat until you’re full. Intuitive fasting can be seen as an intermittent fasting method because, for most people, intuitive fasting leads to fasting times that fulfill the intermittent fasting criteria.
Since Will Cole has published his book Intuitive Fasting, which quickly became a bestseller, this way of eating gained much attention. Intuitive fasting is part of an even broader trend–intuitive eating. It promises weight loss, better health, and better mental wellbeing.
What is intuitive fasting, and what is the science behind these health claims?
Intuitive fasting is very simple. Instead of sticking to a set fasting schedule, you listen to your hunger. You hold off on eating until you’re really hungry. You then eat until you’re full and don’t eat until you’re hungry again.
What does “really hungry” mean? It means that you experience clear signs of hunger. We often feel slightly hungry, but if we wait five minutes, the hunger pangs are gone. That means that you were not really hungry. However, when hunger increases over time, it’s time to eat. You shouldn’t wait until you feel like starving.
What does eating until full mean? You eat until you feel satisfied, you are clearly not hungry anymore, and you don’t have the desire to eat more. But you also don’t overeat, meaning you don’t force in more when you are full.
Once waiting until hungry and eating until full becomes a habit, most people eat around two meals per day. With intuitive fasting, it’s also normal not to eat the same number of meals every day. On some days, you may eat three meals, on others only one–but this is nothing to worry about. What’s important is that you learn to listen to your hunger.
For most people, intuitive fasting results in intermittent fasting. When you eat two meals per day, you automatically reach relatively long fasting times. When the two meals are far apart, you have two very long fasting times.
When the two meals are close together, you have one short eating break and one very long one.
So, you are somewhere between 12-hour and 20/4 intermittent fasting. Even when you eat three meals or more, you should easily achieve a 12-hour overnight fast.
If you want to learn more about intermittent fasting, we invite you to join our intermittent fasting community for women only.
Intuitive fasting is part of an intuitive eating trend that has grown in popularity. The concept of intuitive eating doesn’t only include intuitive fasting (wait until you’re hungry and eat until you’re full) but also an intuitive selection of foods. That means that no foods are forbidden.
The idea behind this is that eliminating foods you enjoy fuels food cravings and can result in binge eating. By allowing yourself also to eat unhealthy foods, you find the right balance and learn to enjoy them in moderation.
We all know that we can lose weight by restricting calories. The problem is that restricting calories makes you hungry. Since no one can resist hunger long-term, you eventually give in and all the weight comes back. For this reason, intuitive eating rejects the dieting mentality. It’s supposed to establish a healthy relationship with food that prevents overeating and binge eating of junk food.
Unfortunately, intuitive eating is a very new field of research, and there aren’t many studies yet. There are no studies specifically for intuitive fasting.
However, intermittent fasting research shows that different intermittent fasting methods all provide similar health benefits (1). This suggests that what matters are regular longer eating breaks. The exact timing and length are of minor importance.
The few available studies on intuitive eating show that there’s a positive relationship between intuitive eating and a healthy weight, as well as certain health markers, such as low blood pressure, and lower blood sugar (2, 3).
People who eat intuitively are also less affected by binge eating and have better psychological health (4).
The problem with these kinds of studies is that they can’t assess whether intuitive eating results in these positive health outcomes or whether people intuitively eat because they are slim and healthy and have no reason to diet. As you probably know from experience, most people only start dieting when they are unhappy with their weight. However, that doesn’t mean that the diet caused the weight gain.
Nevertheless: We know that diets utterly fail when it comes to long-term weight loss, and binge eating and food cravings are widespread dietary problems. Intuitive eating and fasting are promising approaches that may solve these issues.
Some women have to be a bit careful with intermittent fasting, especially with longer fasting times. The female reproductive system thinks that times of famine are not a good time to become pregnant. For this reason, severe calorie restriction can reduce female fertility, at least short term (5).
Intuitive fasting avoids this problem: You eat as soon as you’re hungry and eat until you’re full. This way, your body won’t have the impression that food is scarce and that it’s not safe to conceive a child.
In theory, intuitive fasting makes sense. To only eat when you’re hungry and to eat until you’re full without overeating likely results in a healthy balance between severe calorie restriction and overeating.
One problem is that it is not always easy to realize in real life. We have set lunch times at work, eat together with our family at a specific time of the day and schedule dinner events with friends. When everybody else is eating, you don’t want to say: “Oh, I’m not really hungry yet, I’ll wait another hour.”
Does that mean that intuitive fasting is not compatible with social life?
No, but you have to find the right balance. When you have a dinner appointment at 7 pm and feel hungry at 5 pm, you may wait two more hours. Or when you’re a bit hungry at noon and would usually wait for another two hours, it might be a good idea to eat a bit earlier to make sure that you are hungry for your dinner date.
In different words: 100% intuitive eating is hardly compatible with social life. But with some small compromises, you can make sure that you’re hungry at specific times of the day.
1. de Cabo R, Mattson MP. Effects of Intermittent Fasting on Health, Aging, and Disease. N Engl J Med. Dec 26 2019;381(26):2541-2551. doi:10.1056/NEJMra1905136
2. Quansah DY, Gilbert L, Gross J, Horsch A, Puder JJ. Intuitive eating is associated with improved health indicators at 1-year postpartum in women with gestational diabetes mellitus. J Health Psychol. Jul 2021;26(8):1168-1184. doi:10.1177/1359105319869814
3. Quansah DY, Gross J, Gilbert L, Helbling C, Horsch A, Puder JJ. Intuitive eating is associated with weight and glucose control during pregnancy and in the early postpartum period in women with gestational diabetes mellitus (GDM): A clinical cohort study. Eat Behav. Aug 2019;34:101304. doi:10.1016/j.eatbeh.2019.101304
4. Hazzard VM, Telke SE, Simone M, Anderson LM, Larson NI, Neumark-Sztainer D. Intuitive eating longitudinally predicts better psychological health and lower use of disordered eating behaviors: findings from EAT 2010-2018. Eat Weight Disord. Feb 2021;26(1):287-294. doi:10.1007/s40519-020-00852-4
5. Kumar S, Kaur G. Intermittent fasting dietary restriction regimen negatively influences reproduction in young rats: a study of hypothalamo-hypophysial-gonadal axis. PLoS One. 2013;8(1):e52416. doi:10.1371/journal.pone.0052416
6. Sutton EF, Beyl R, Early KS, Cefalu WT, Ravussin E, Peterson CM. Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metab. Jun 5 2018;27(6):1212-1221 e3. doi:10.1016/j.cmet.2018.04.010
7. Jamshed H, Beyl RA, Della Manna DL, Yang ES, Ravussin E, Peterson CM. Early Time-Restricted Feeding Improves 24-Hour Glucose Levels and Affects Markers of the Circadian Clock, Aging, and Autophagy in Humans. Nutrients. May 30 2019;11(6)doi:10.3390/nu11061234
8. Foster DW. Studies in the ketosis of fasting. J Clin Invest. Aug 1967;46(8):1283-96. doi:10.1172/JCI105621
If you're fond of running and want to do intermittent fasting, you may have questions. Here are the answers.