Can intermittent fasting cause constipation?
Intermittent fasting can temporarily cause constipation, but in people who already suffer from constipation as a bowel syndrome, the same dietary pattern appears to help instead. It depends on your personal situation.
Intermittent fasting can temporarily cause constipation. In a randomised study of people at increased risk of type 2 diabetes, participants in both the fasting group and the calorie-restriction group reported constipation more often than the control group. The complaints were mild and resolved on their own over time.
Not everyone with gut complaints tells the same story. A pilot study in people with irritable bowel syndrome whose main complaint was constipation actually showed that fasting daily for 8 weeks on a 16:8 schedule (eating within an 8-hour window, nothing for 16 hours) considerably reduced symptoms. Note, however, that this study had no control group, so there is no certainty that fasting itself made the difference.
There is a theoretical explanation for both sides. Eating less means less volume in the gut, which can slow bowel movement. At the same time, research suggests that time-restricted eating may help restore the biological rhythm of the gut, which could in turn benefit bowel movement. Which effect dominates for you probably depends on how much you eat, when you eat, and how sensitive your gut is.
The answer rests on a randomised study of 209 people, a pilot study of 97 people without a control group, and a review article on the mechanism. The evidence is thin: the randomised study described constipation as a side effect but did not measure it as a primary outcome, and the pilot study had no comparison group. No research yet clearly distinguishes between who develops constipation and who instead experiences relief.
Does intermittent fasting lower your cholesterol?
Intermittent fasting probably lowers total cholesterol and LDL modestly, but its effect on 'good' HDL cholesterol is unclear and long-term data are limited. It is a worthwhile strategy as a complement to, not a replacement for, proven treatments.
What are the benefits of combining sauna with an ice bath?
The combination of sauna and ice bath demonstrably lowers cortisol and promotes blood flow after exercise, but whether it delivers more than the individual methods has not yet been established. Feel free to use it as a recovery ritual, but do not expect proven benefits beyond those of sauna or ice bath separately.
Is intermittent fasting worth it?
Intermittent fasting helps with weight loss and improves blood glucose and insulin, but over the longer term it does no better than simply eating less. If the fasting structure helps you stick to it, it is worth it; do not expect additional health benefits that come for free.
Is intermittent fasting safe during pregnancy?
For healthy pregnant women, fasting does not appear to increase major risks such as preterm birth or low birth weight, but fatigue and dehydration are real complaints. If you have diabetes or are early in your pregnancy, discuss fasting with your doctor first.