Caloric restriction in C57BL/6J mice mimics therapeutic fasting in humans.
Level 5 - mechanism / opinion, no new human data
Preclinical animal research (no human subjects)
PubMed 16709251 · doi:10.1186/1476-511X-5-13
What was done
Adult female C57BL/6J mice (n = 4 per group, total n = 12) were assigned to one of three standard chow diets: unrestricted (UR), 3 weeks of caloric restriction to reduce body weight by 15–20% (R), or 3 weeks of restriction followed by 3 weeks of ad libitum re-feeding (R-RF). Body weight and food intake were measured throughout the study. At termination, plasma glucose, beta-hydroxybutyrate, and lipids (phosphatidylcholine, phosphatidylinositol, cholesterol, triglycerides, and fatty acids) were measured.
What was found
No numerical values or effect sizes were reported in the abstract. Compared with UR mice, restricted (R) mice had significantly lower plasma glucose, phosphatidylcholine, cholesterol, and triglycerides, and significantly higher plasma fatty acids and beta-hydroxybutyrate. Caloric restriction had no effect on plasma phosphatidylinositol. In re-fed (R-RF) mice, body weight and plasma lipids returned to unrestricted levels, but food intake and plasma glucose remained significantly lower than pre-restriction levels.
Why it matters
The study suggests that short-term caloric restriction in mice induces a persistent reset in food intake and glucose regulation that endures past re-feeding, modeling metabolic biomarker shifts seen in human fasting.
Limits
The study was conducted in a very small animal sample (female mice, n = 4 per group) with no direct human testing. The abstract reports no numerical values, variances, or p-values. Long-term outcomes beyond three weeks of re-feeding were not evaluated.
Cited by
- supports Following a 40% calorie restriction fast and refeeding, mice maintained constant body weight while consuming 8% less food.