Research and videos
Intermittent fasting and time-restricted eating: the research and Kevin's videos
How long should I fast, is it different for women or older carriers, and does fasting protect my brain?
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This page has no results from Phoenix members yet. It shows what published research says, and what Kevin and the experts say in his videos.
See what Phoenix members have measuredHow long should I fast, is it different for women or older carriers, and does fasting protect my brain?
Eating windows and fasting days lower weight, and probably improve blood sugar and LDL a little, mostly because people eat less. Whether fasting protects the human brain is too early to say: the amyloid and memory benefits come from mice, and an 8-week trial in older adults found no edge over a healthy diet. Very short daily eating windows were linked to higher death rates in one large observational study, so moderate windows are the cautious choice.
What the research says
Grade CAPOE4-specific evidence: none
Fasting schedules lower weight (high certainty) and probably improve insulin and LDL slightly, but there is no human evidence yet that they protect the brain, and very short eating windows may carry risk (low certainty).
Key studies
Patikorn 2021, JAMA Netw OpenGrade A
Umbrella review of 130 trials: fasting lowered weight, LDL and insulin markers; most evidence was low quality.
Read on PubMed (opens in a new tab)Allaf 2021, Cochrane Database Syst RevGrade A
Fasting beat ordinary eating for weight but not ordinary calorie cutting; heart outcomes unknown.
Read on PubMed (opens in a new tab)Sutton 2018, Cell MetabGrade B
Early eating window improved insulin sensitivity and blood pressure without weight loss (8 men with prediabetes).
Read on PubMed (opens in a new tab)
4 more key studies
Kapogiannis 2024, Cell MetabGrade C
8-week trial in 40 older adults: 5:2 fasting and a healthy diet improved brain markers about equally.
Read on PubMed (opens in a new tab)Senderovich 2023, Med Princ PractGrade C
Only 9 low-quality trials have tested fasting on cognition; no clear benefit shown.
Read on PubMed (opens in a new tab)Whittaker 2023, Cell MetabGrade D
Animal or lab study
In two Alzheimer's mouse models, time-restricted feeding cut amyloid and improved memory.
Read on PubMed (opens in a new tab)Mao 2025, Aging CellGrade C
33,052 US adults: eating windows of 8 hours or less linked to higher death rates; lowest risk near 11-12 hours (observational).
Read on PubMed (opens in a new tab)
What Kevin and experts say
4 passages for, 4 with a caution
Now showing: Dr. Kevin Tran · 6:12
Open on YouTube (opens in a new tab)For4 passages
Time-restricted feeding improved memory in mice.
“Third, their memory improved, so the mice performed better on novel object recognition and spatial memory task.”
Dr. Kevin Tran, Founder of The Phoenix Community, Doctor of Pharmacy, APOE4/4 carrier
Intermittent fasting worked for him and he enjoys it.
“She said I need to do intermittent fasting and I said, well, I already do that and I love it.”
John Yoder, Phoenix member, retired physician, APOE3/4 carrier
In mice, time-restricted eating reduced Alzheimer's changes.
Dr. Kevin Tran
Watch the Short on YouTube (opens in a new tab)
With a caution4 passages
Most fasting-brain evidence is from mice.
“human trials are very limited”
Dr. Kevin Tran, Founder of The Phoenix Community, Doctor of Pharmacy, APOE4/4 carrier
Very short eating windows are a red flag.
“had a 91% higher risk of cardiovascular death”
Dr. Kevin Tran, Founder of The Phoenix Community, Doctor of Pharmacy, APOE4/4 carrier
Newer research: the peer-reviewed 2025 analysis of 33,052 US adults found a smaller link than the 91% conference figure, and it is observational.
Read the study (opens in a new tab)
Fasting on top of chronic stress can push cortisol up.
Dr. Kevin Tran
Watch the Short on YouTube (opens in a new tab)
Women may get a bigger cortisol spike from fasting.
Dr. Kevin Tran
Watch the Short on YouTube (opens in a new tab)
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