Abstract Starvation is a frequent challenge for many animals in their natural habitats. In aquatic ecosystems, certain fish and shellfish experience prolonged and short‐term starvation stress, particularly during periods of extreme weather in the wild and inadequate feeding practices in aquaculture systems. Nutritional deficiencies caused by either short‐term or prolonged starvation can lead to stress‐induced health issues in fish and shellfish. Our study aimed to assess the impact of repeated short‐term fasting and refeeding on immunological parameters and growth performance in the disk abalo

The effects of long-term starvation on the activities of sucrase, lactase, and aminopeptidase, and on their respective mRNA were determined in the small intestine of thyroidectomized and sham-operated adult rats. Thyroidectomy reduced the protein loss at the level of the intestinal brush border membranes during starvation. Prolonged fasting caused a significant decrease in sucrase activity, but thyroidectomy partly prevented this effect. However, the amount of the corresponding mRNA dropped during long term starvation without incidence of thyroidectomy. Lactase activity in the brush border mem

Starvation, which is common in the wild, appears to initiate a genetic program that allows fruitflies to remain awake without the sleepiness and cognitive impairments that typically follow sleep deprivation. Extended periods of waking result in physiological impairments in humans, rats, and flies. Sleep homeostasis, the increase in sleep observed following sleep loss, is believed to counter the negative effects of prolonged waking by restoring vital biological processes that are degraded during sleep deprivation. Sleep homeostasis, as with other behaviors, is influenced by both genes and envir

<h4>Background/objectives</h4>Water-only fasting is practiced for metabolic and therapeutic purposes, yet its specific effects on lipid fractions remain inconsistently reported. This systematic review and meta-analysis evaluated lipid responses to water-only fasting across varying durations and fasting protocols.<h4>Methods</h4>PubMed, Scopus, and Web of Science (2000-2025) were searched for human studies reporting pre-post lipid measurements under water-only fasting. Thirty-two studies met eligibility criteria. Effect sizes were calculated as Hedges' g using random-effects models. Duration-dependent responses were evaluated through subgroup analyses (≤3 days, >3 days) and piecewise threshold meta-regression. Publication bias was assessed via funnel plots and Egger's tests.<h4>Results</h4>Water-only fasting produced lipid-specific and duration-dependent adaptations. HDL decreased significantly overall (g = -0.233), with no change in ≤3-day fasts but clear reductions in >3-day fasts; threshold analysis identified an early decline within the first ~3 days. LDL increased significantly (g = 0.489) and across all duration subgroups, showing a biphasic trajectory with progressive elevation up to ~10 days followed by attenuation or partial reversal. Total cholesterol also increased (g = 0.343), with the largest effects in >3--day fasts and a nonlinear threshold at ~5 days marking stabilization or modest decline thereafter. Triglycerides showed no significant overall effect (g = -0.039), characterized by reductions in ≤3-day fasts, increases in >3-day fasts; a marked early-phase threshold was observed at ~2.5 days. VLDL exhibited small, non-significant changes (g = 0.203) with substantial heterogeneity and limited data. Evidence of publication bias was detected for LDL and total cholesterol but not for HDL, triglycerides, or VLDL.<h4>Conclusion</h4>Water-only fasting induces distinct, duration-dependent lipid adaptations. LDL and total cholesterol demonstrate early increases followed by stabilization, HDL decreases mainly during multi-day fasts, while triglycerides and VLDL show no uniform pattern. These findings highlight the importance of considering fasting duration when evaluating cardiometabolic effects and underscore the need for rigorously controlled, longer-term clinical trials.

The following story tells the details of the ketone body metabolism, focusing on the needs of the brain in prolonged fasting conditions. This literary composition highlights the use of ketone bodies as an important metabolic adaptation that avoids excessive protein degradation and allows for greater survival. The liver produces ketone bodies that are released into the bloodstream and exported to the brain, which then absorbs and transforms them into acetyl-CoA. These molecules with central role in metabolism generate energy through the Krebs cycle, electron transport chain, and oxidative phosp