Short-term fasting
Short-term fasting has been studied in 3 papers since 2020: none in people yet, 1 in animals, 2 reviews; 1 in the past year. The research so far is in animals. The newest paper, Jul 15, 2026: “Comparative efficacy of dietary interventions for overweight or obese adults with type 2 diabetes: a systematic review and network meta-analysis of randomized controlled…”.
3 papers study it8 findingsUpdated
“Preoperatively, circulating T cells were less abundant and less activated, but also immune suppressive regulatory T cells (Tregs) were less abundant after fasting for approximately 40 hours.”
None of its findings points the other way.
- 3 independent labs in 3 countries
- Funders: Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja and 5 more
- Animals1
What did studies of Short-term fasting find?
8Studies of Short-term fasting measured 8 outcomes; the most studied are central memory T cells (1 study), dendritic cells (1) and B cell levels (1).
Central memory T cells
downin humans1
1 study
Central memory T cells
downin humans1
Short-term fasting decreases central memory T cells in humans (at time of surgery).
“However, CD8+ and CD4+ Tcm cells were decreased at this stage, suggesting an arrest in T cell development, as seen for B cells.”
Human trialat time of surgeryperipheral bloodan average of 61.0 hours
Short-term fasting before living kidney donation has an immune-modulatory effect
Frontiers in immunology
Dendritic cells
upin humans1
1 study
Dendritic cells
upin humans1
Short-term fasting increases dendritic cells in humans (upon caloric restriction).
“Finally, cross-presenting type 1 conventional DCs (cDC1s) increased upon caloric restriction, implying the potential to initiate a type 1 cytotoxic immune response, e.g. against viral infection after STF.”
Human trialupon caloric restrictionperipheral bloodan average of 61.0 hours
Short-term fasting before living kidney donation has an immune-modulatory effect
Frontiers in immunology
B cell levels
upin humans1
1 study
B cell levels
upin humans1
Short-term fasting increases B cell levels in humans (preoperatively).
“Concomitantly, (naïve) B cells expressing PD-1 and HLA-DR became more abundant in the periphery, suggesting a reduction in specialized B cell subsets and/or B cell development.”
Human trialpreoperativelyperipheral bloodan average of 61.0 hours
Short-term fasting before living kidney donation has an immune-modulatory effect
Frontiers in immunology
T cell levels
downin humans1
1 study
T cell levels
downin humans1
Short-term fasting decreases T cell levels in humans (preoperatively after fasting for approximately 40 hours).
“Preoperatively, circulating T cells were less abundant and less activated, but also immune suppressive regulatory T cells (Tregs) were less abundant after fasting for approximately 40 hours.”
Human trialpreoperatively after fasting for approximately 40 hoursperipheral bloodan average of 61.0 hours
Short-term fasting before living kidney donation has an immune-modulatory effect
Frontiers in immunology
Lean mass
downin humans1
1 study
Lean mass
downin humans1
Short-term fasting decreases lean mass in humans (MD -1.26, 95% CI -2.16 to -0.47).
“STF lead to decline in lean mass (MD: -1.26; 95% CI: -2.16, -0.47).”
Review
The international journal of behavioral nutrition and physical activity
IRS1, IRS2, PI3K and mTOR
no changein rats1
1 study
IRS1, IRS2, PI3K and mTOR
no changein rats1
Short-term fasting showed no clear effect on IRS1, IRS2, PI3K and mTOR in rats.
“the hypothalamic content of total and activated IRS1, IRS2, PI3K, and mTOR remained unchanged”
Animalshypothalamus
Short-term fasting differentially regulates PI3K/AkT/mTOR and ERK signalling in the rat hypothalamus
Mechanisms of ageing and development
Activated ERK1/2
upin rats1
1 study
Activated ERK1/2
upin rats1
Short-term fasting increases activated ERK1/2 in rats.
“The levels of activated ERK1/2 were increased after six-hour fasting.”
Animalshypothalamussix hours
Short-term fasting differentially regulates PI3K/AkT/mTOR and ERK signalling in the rat hypothalamus
Mechanisms of ageing and development
Phosphorylated AKT1/2/3
downin rats1
1 study
Phosphorylated AKT1/2/3
downin rats1
Short-term fasting decreases phosphorylated AKT1/2/3 in rats (short-term food deprivation).
“but phosphorylated AKT1/2/3 was decreased”
Animalsshort-term food deprivationhypothalamus
Short-term fasting differentially regulates PI3K/AkT/mTOR and ERK signalling in the rat hypothalamus
Mechanisms of ageing and development