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Overweight and obesity became the worldwide epidemic resulting from overeating especially when a so-called Western diet rich in carbohydrates and fats is used. It is widely accepted that limitation of food consumption could help to withstand such state of adult organism, but information about younger groups is contradictory. The present study was undertaken to characterize the effects of intermittent fasting, using an every other day (EOD) fasting/feeding protocol, on hematological parameters and biochemical blood plasma indices in young mice from one to two months old. It was shown that intermittently fasted mice were characterized by a reduced body weight, reduced total number of blood leucocytes, lower glucose and lactate levels and higher activity of alanine aminotransferase and aspartate aminotransferase in blood plasma as compared with the age-matched control mice. To gain the same mass EOD animals needed to eat more food than ad libitum fed animals. These differences may probably be explained by a need to expend certain resources to combat stress induced by intermittent fasting. Our data showed that EOD feeding at a young age may negatively influence young mammals.

The effects of an alpha-ketoglutarate-supplemented diet on lifespan and functional senescence were evaluated in the Canton S strain of Drosophila melanogaster. The results suggest that effects of dietary alpha-ketoglutarate (AKG) are dose- and gender-dependent. In males, diets containing 1-10 mM AKG did not affect mean and maximum lifespans, except that an increased maximum lifespan observed at 10 mM AKG. Diet with 20 mM AKG shortened median lifespan and had no effect on maximum lifespan of males. In females, diets with low concentrations of AKG (1 and 5 mM) did not affect lifespan, whereas diets supplemented with 10 and 20 mM AKG increased both median and maximum lifespans. At a lifespan-prolonging concentration (10 mM), AKG decreased fecundity, increased cold resistance and had no effect on climbing activity or resistance to oxi­dative stress in flies of either gender at middle (24 days) and old (40 days) ages. Moreover, middle-aged AKG-fed females but not males were more resistant to heat stress that was accompanied by higher levels of HSP90 protein as compared with controls. Middle-aged flies on AKG-supplemented diets showed elevated oxidative stress and had higher total protein and triacylglycerol levels as compared with controls. Hence, anti-aging effects of AKG do not seem to be related to preventing oxidative stress development but involve metabolic rearrangement and synthesis of specific protective proteins, which aid to resist destructive processes with age.

The effects of short-term burst (5 min at 1.8 m/s) swimming and long-term cruiser (60 min at 1.2 m/s) swimming on maximal enzyme activities and enzyme distribution between free and bound states were assessed for nine glycolytic and associated enzymes in tissues of horse mackerel, Trachurus mediterraneus ponticus. The effects of exercise were greatest in white muscle. The activities of phosphofructokinase (PFK), pyruvate kinase (PK), fructose-1,6-bisphosphatase (FBPase), and phosphoglucomutase (PGM) all decreased to 47, 37, 37 and 67%, respectively, during 60-min exercise and all enzymes except phosphoglucoisomerase (PGI) and PGM showed a change in the extent of binding to subcellular particulate fractions during exercise. In red muscle, exercise affected the activities of PGI, FBPase, PFK, and lactate dehydrogenase (LDH) and altered percent binding of only PK and LDH. In liver, exercise increased the PK activity 2.3-fold and reduced PGI 1.7-fold only after 5 min of exercise but altered the percent binding of seven enzymes. Fewer effects were seen in brain, with changes in the activities of aldolase and PGM and in percent binding of hexokinase, PFK and PK. Changes in enzyme activities and in binding interactions with subcellular particulate matter appear to support the altered demands of tissue energy metabolism during exercise.