Intermittent Fasting Knowledge Center

Science-backed answers from the book and community.

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80 unanswered questions

  1. 01

    Should I fast on days when I'm sick with a cold, or will it slow my recovery?slug:should-i-fast-when-sick-with-cold

    10 Jun 2026

  2. 02

    Should I fast on days when I'm sick with a cold, or will it slow my recovery?

    10 Jun 2026

  3. 03

    Has anyone used fasting to recover from COVID long-haul symptoms?slug:has-anyone-used-fasting-to-recover-from-covid-long-haul-symptoms

    10 Jun 2026

  4. 04

    Has anyone used fasting to recover from COVID long-haul symptoms?

    10 Jun 2026

  5. 05

    My calves cramp badly at night since I started fasting. Is this an electrolyte issue?slug:my-calves-cramp-at-night-fasting

    9 Jun 2026

  6. 06

    My calves cramp badly at night since I started fasting. Is this an electrolyte issue?

    9 Jun 2026

  7. 07

    I feel incredible after a 48-hour fast but not sure if it's healthy to do this regularly. Thoughts?slug:feel-incredible-after-48-hour-fast

    9 Jun 2026

  8. 08

    I feel incredible after a 48-hour fast but not sure if it's healthy to do this regularly. Thoughts?

    9 Jun 2026

  9. 09

    Can someone with a history of gallstones do intermittent fasting safely?slug:can-someone-with-gallstones-do-intermittent-fasting

    9 Jun 2026

  10. 10

    Can someone with a history of gallstones do intermittent fasting safely?

    9 Jun 2026

  11. 11

    Does apple cider vinegar break a fast? I've seen very different answers online.slug:does-apple-cider-vinegar-break-a-fast

    8 Jun 2026

  12. 12

    Does apple cider vinegar break a fast? I've seen very different answers online.

    8 Jun 2026

  13. 13

    I started fasting and my menstrual cycle became irregular. Has this happened to you?slug:i-started-fasting-menstrual-cycle-irregular

    8 Jun 2026

  14. 14

    I started fasting and my menstrual cycle became irregular. Has this happened to you?

    8 Jun 2026

  15. 15

    Can fasting help with hormonal belly fat after menopause?

    8 Jun 2026

  16. 16

    Can fasting help with hormonal belly fat after menopause?

    8 Jun 2026

  17. 17

    Does it matter if my eating window changes by an hour or two each day, or does it need to be exact?

    7 Jun 2026

  18. 18

    Does it matter if my eating window changes by an hour or two each day, or does it need to be exact?

    7 Jun 2026

  19. 19

    I lost weight the first month then gained 2kg back while doing the same thing. What happened?

    7 Jun 2026

  20. 20

    I lost weight the first month then gained 2kg back while doing the same thing. What happened?

    7 Jun 2026

  21. 21

    How do you fast when your job requires you to socialize over lunch every day?

    7 Jun 2026

  22. 22

    How do you fast when your job requires you to socialize over lunch every day?

    7 Jun 2026

  23. 23

    Can I do intermittent fasting if I have an underactive thyroid (hypothyroidism)?

    6 Jun 2026

  24. 24

    Can I do intermittent fasting if I have an underactive thyroid (hypothyroidism)?

    6 Jun 2026

  25. 25

    I feel euphoric and almost high when deep in a fast. Is this normal and what causes it?

    6 Jun 2026

  26. 26

    I feel euphoric and almost high when deep in a fast. Is this normal and what causes it?

    6 Jun 2026

  27. 27

    My breath smells terrible when I'm fasting. Is this just ketosis and will it ever go away?

    6 Jun 2026

  28. 28

    Has anyone used fasting to get off blood pressure medication? What was your experience?

    5 Jun 2026

  29. 29

    Has anyone used fasting to get off blood pressure medication? What was your experience?

    5 Jun 2026

  30. 30

    Does the type of exercise matter when fasting — cardio vs. weights?

    5 Jun 2026

  31. 31

    Does the type of exercise matter when fasting — cardio vs. weights?

    5 Jun 2026

  32. 32

    I'm 65 and my doctor says fasting is risky at my age. Is this true?

    5 Jun 2026

  33. 33

    My sleep is much worse since I started fasting — I wake up at 3am every night. What's going on?

    4 Jun 2026

  34. 34

    My sleep is much worse since I started fasting — I wake up at 3am every night. What's going on?

    4 Jun 2026

  35. 35

    Can intermittent fasting help with inflammation from arthritis?

    4 Jun 2026

  36. 36

    Can intermittent fasting help with inflammation from arthritis?

    4 Jun 2026

  37. 37

    I drink 3L of water during my fast but still feel dehydrated. What's happening?

    4 Jun 2026

  38. 38

    I drink 3L of water during my fast but still feel dehydrated. What's happening?

    4 Jun 2026

  39. 39

    Does stress eating get better with fasting, or does fasting make it worse?

    4 Jun 2026

  40. 40

    Does stress eating get better with fasting, or does fasting make it worse?

    4 Jun 2026

  41. 41

    What is the best way to break a 24-hour fast without feeling sick?

    3 Jun 2026

  42. 42

    What is the best way to break a 24-hour fast without feeling sick?

    3 Jun 2026

  43. 43

    I feel worse on fasting days than non-fasting days. Is that normal at the beginning?

    3 Jun 2026

  44. 44

    I feel worse on fasting days than non-fasting days. Is that normal at the beginning?

    3 Jun 2026

  45. 45

    Can fasting cause constipation? Mine has been really bad since I started.

    2 Jun 2026

  46. 46

    I've been doing 18:6 for 4 months with no results. Should I switch to OMAD?

    2 Jun 2026

  47. 47

    Does drinking decaf coffee have the same benefits as regular coffee during fasting?

    2 Jun 2026

  48. 48

    Can I have a small handful of nuts during my fast if I'm really struggling? Will it ruin everything?

    2 Jun 2026

  49. 49

    I feel great but my BMI is still "obese." Should I care about BMI or just focus on how I feel?

    1 Jun 2026

  50. 50

    Has anyone reversed pre-diabetes with intermittent fasting alone, without medication?

    1 Jun 2026

  51. 51

    My partner wants to do intermittent fasting but they have a history of anorexia. Is it safe?

    31 May 2026

  52. 52

    I always eat healthy during my eating window but I'm not losing weight. What could be the issue?

    30 May 2026

  53. 53

    Does black tea break a fast the same way coffee doesn't, or are they different?

    30 May 2026

  54. 54

    Has anyone tried fasting while pregnant? I know it's controversial but curious about experiences.

    29 May 2026

  55. 55

    My blood sugar drops to 60 mg/dL when fasting and I feel shaky. Should I stop?

    29 May 2026

  56. 56

    I'm a nurse doing 12-hour shifts. How do I fit fasting around a schedule that changes every week?

    29 May 2026

  57. 57

    Can intermittent fasting help with acid reflux or GERD?

    29 May 2026

  58. 58

    I feel mentally sharper when fasting but my gym performance dropped. Is this a phase that passes?

    28 May 2026

  59. 59

    Does it matter what time of day I eat my one meal on OMAD, or can it be breakfast?

    28 May 2026

  60. 60

    I've been fasting for 6 months and have lost 20kg. Now I want to stop losing weight — how do I maintain?

    28 May 2026

  61. 61

    What is the difference between hunger and wanting food out of habit? How do you tell them apart?

    28 May 2026

  62. 62

    I feel amazing fasting but my family is worried I have an eating disorder. How do I explain this to them?

    28 May 2026

  63. 63

    My skin has been breaking out since I started fasting. Has this happened to anyone else?

    28 May 2026

  64. 64

    How do you handle hunger at work when you can smell food from the kitchen or break room?

    27 May 2026

  65. 65

    My stomach makes very loud noises when I'm fasting. Is this normal and how do I manage it in public?

    27 May 2026

  66. 66

    I've been told I need to eat every 3 hours for muscle building. Can I build muscle while fasting?

    27 May 2026

  67. 67

    Does the length of the eating window matter, or is it just about when you start and stop?

    27 May 2026

  68. 68

    I feel great fasting Monday to Friday but always overeat on weekends. How do I stop undoing my progress?

    27 May 2026

  69. 69

    How do you fast while traveling across time zones? Do you adjust your window for the new timezone?

    26 May 2026

  70. 70

    Is it OK to drink black coffee right when I wake up at 6am if my fasting window started at midnight?

    26 May 2026

  71. 71

    I've been fasting for 3 months and feel great but my cholesterol went up. Should I be worried?

    26 May 2026

  72. 72

    Can I fast during Ramadan and combine it with 16:8 or OMAD for better results?

    26 May 2026

  73. 73

    I'm 58 and my metabolism feels like it's completely stopped. Is it too late for fasting to work for me?

    25 May 2026

  74. 74

    Has anyone reversed their fatty liver with intermittent fasting? How long did it take?

    25 May 2026

  75. 75

    I get incredibly hungry at exactly 11am every day even though I'm eating a big dinner at 7pm. Any tips?

    25 May 2026

  76. 76

    Does intermittent fasting affect breast milk supply? I'm still nursing my 8-month-old.

    24 May 2026

  77. 77

    My husband thinks skipping breakfast is bad for your heart. Where can I find research to show him?

    24 May 2026

  78. 78

    I lost 10kg quickly then completely stalled for 6 weeks. How do I break a plateau?

    24 May 2026

  79. 79

    Can you drink sparkling water during the fasting window or does the carbonation break the fast?

    24 May 2026

  80. 80

    My hair started falling out after 3 months of fasting. Has this happened to anyone else?

    24 May 2026