Protein deficiency attenuates the effects of alloxan on insulin secretion and glucose homeostasis in rats.

We have investigated the effect of alloxan on insulin secretion and glucose homeostasis in rats maintained on a 17% protein (normal protein, NP) or 6% protein (low protein, LP) diet from weaning (21 days old) to adulthood (90 days old). The incidence of alloxan diabetes was higher in the NP (3.5 times) than in the LP group. During an oral glucose tolerance test, the area under serum glucose curve was lower in LP (57%) than in NP rats while there were no differences between the two groups in the area under serum insulin curve. The serum glucose disappearance rate (Kitt) after exogenous insulin administration was higher in LP (50%) than in NP rats. In pancreatic islets isolated from rats not injected with alloxan, acute exposure to alloxan (0.05 mmol/L) reduced the glucose- or arginine-stimulated insulin secretion of NP islets by 78% and 56%, respectively, whereas for islets from LP rats, the reduction was 47% and 17% in the presence of glucose and arginine, respectively. Alloxan treatment reduced the glucose oxidation in islets from LP rats to a lesser extent than in NP islets (23% vs. 56%). In conclusion, alloxan was less effective in producing hyperglycemia in rats fed a low protein diet than in normal diet rats. This effect is attributable to an increased peripheral sensivity to insulin in addition to a better preservation of glucose oxidation and insulin secretion in islets from rats fed a low protein diet.     

Impaired insulin secretion and decreased expression of the nutritionally responsive ribosomal kinase protein S6K-1 in pancreatic islets from malnourished rats

Low protein diet has been shown to affect the levels and activities of several enzymes from pancreatic islets. To further extend the knowledge on how malnutrition affects insulin secretion pathway, we investigated in this work the insulin release induced by glucose or leucine, an insulin secretagogue, and the expression of insulin receptor (IR), insulin receptor substrate 1 (IRS1), phosphatidylinositol 3-kinase (PI3K), and p70S6K1 (S6K-1) proteins from pancreatic islets of rats fed a normal (17%; NP) or a low (6%; LP) protein diet for 8 weeks. Isolated islets were incubated for 1 h in Krebs-bicarbonate solution containing 16.7 mmol/L of glucose, or 2.8 mmol/L of glucose in the presence or absence of 20 mmol/L of leucine. Glucose- and leucine-induced insulin secretions were higher in NP than in LP islets. Western blotting analysis showed an increase in the expression of IR and PI3K protein levels whereas IRS1 and S6K-1 protein expression were lower in LP compared to NP islets. In addition, S6K-1 mRNA expression was also reduced in islets from LP rats. Our data indicate that a low protein diet modulates the levels of several proteins involved in the insulin secretion pathway. Particularly, the decrease in S6K-1 expression might be an important factor affecting either glucose- or leucine-induced insulin secretion.     

Increased L-CPT-1 activity and altered gene expression in pancreatic islets of malnourished adult rats: a possible relationship between elevated free fatty acid levels and impaired insulin secretion

Intrauterine growth restriction is associated with chronically elevated levels of serum fatty acids and reduced glucose-stimulated insulin secretion. Lipid metabolism in pancreatic beta cells is critical for the regulation of insulin secretion, and the chronic exposure to fatty acids results in higher palmitate oxidation rates and an altered insulin response to glucose. Using a rat model of isocaloric protein restriction, we examined whether pre- and postnatal protein malnutrition influences the properties of pancreatic islet carnitine palmitoyltransferase-1 (liver isoform, L-CPT-1), a rate-limiting enzyme that regulates fatty acid oxidation in mitochondria. The activity of L-CPT-1 in pancreatic islets increased in the low protein (LP), although the L-CPT-1 mRNA levels were unaffected by malnutrition. The susceptibility of enzyme to inhibition by malonyl-CoA was unaltered and the content of malonyl-CoA was reduced in LP cells. Because the mitochondrial oxidation of fatty acids is related to the altered expression of a number of genes encoding proteins involved in insulin secretion, the levels of expression of insulin and GLUT-2 mRNA were assessed. A reduced expression of both genes was observed in malnourished rats. These results provide further evidence that increased L-CPT-1 activity and changes in gene expression in pancreatic islets may be involved in the reduced insulin secretion seen in malnourished rats.     

Low protein diet confers resistance to the inhibitory effects of interleukin 1beta on insulin secretion in pancreatic islets*

High protein content in the diet during childhood and adolescence has been associated to the onset insulin-dependent diabetes mellitus. We investigated the effect of interleukin-1beta (IL-1beta) on insulin secretion, glucose metabolism, and nitrite formation by islets isolated from rats fed with normal protein (NP, 17%) or low protein (LP, 6%) after weaning. Pretreatment of islets with IL-1beta for 1 h or 24 h inhibited the insulin secretion induced by glucose in both groups, but it was less marked in LP than in NP group. Islets from LP rats exhibited a decreased IL-1beta-induced nitric oxide (NO) production, lower inhibition of D-[U(14)C]-glucose oxidation to (14)CO(2) and less pronounced effect of IL-1beta on alpha-ketoisocaproic acid-induced insulin secretion than NP islets. However, when the islets were stimulated by high concentrations of K(+) the inhibitory effect of IL-1beta on insulin secretion was not different between groups. In conclusion, protein restriction protects beta-cells of the deleterious effect of IL-1beta, apparently, by decreasing NO production. The lower NO generation in islets from protein deprived rats may be due to increased free fatty acids oxidation and consequent alteration in Ca(2+) homeostasis.     

Feeding time synchronizes clock gene rhythmic expression in brain and liver of goldfish (Carassius auratus)

Little is known about the feeding time dependence of clock gene expression in fish. The aim of the present study was to investigate whether a scheduled feeding time can entrain the rhythmic expression of several clock genes (period and cryptocrome) in the brain and liver of a teleost, the goldfish. Fish maintained under continuous light (LL) conditions were divided into 3 groups. Two groups were fed daily at 1000 h and 2200 h, respectively, and the third group was subjected to a random schedule regime. After 30 days, the fishes under 24-h food deprivation were sacrificed through a 24-h cycle, and clock gene expression in the optic tectum, hypothalamus, and liver was quantified by real-time PCR. The findings pointed to differences between the central and peripheral tissues studied. In the absence of a light-dark cycle (constant light), a scheduled feeding regime was necessary and sufficient to maintain both the rhythmic expression of several clock genes in the optic tectum and hypothalamus, as well as daily rhythms in locomotor activity. In contrast, neither locomotor activity nor clock gene expression in brain tissues was synchronized in randomly fed fish. However, in the liver, most of the clock genes studied presented significant daily rhythms in phase (related to the time of the last meal) in all 3 experimental groups, suggesting that the daily rhythm of clock genes in this organ only depends on the last meal time. The data suggest that, as in mammals, the smooth running of the food entrainable oscillator (FEO) in fish involves the rhythmic expression of several clock genes (Per1 and Cry3) in the central and peripheral structures. The results also indicate that the food anticipatory activity (FAA) in goldfish is not only the result of rhythmic clock gene expression in the liver because rhythmic clock gene expression was observed in randomly fed fishes, while FAA was not observed.     

Effects of biotin deficiency on pancreatic islet morphology, insulin sensitivity and glucose homeostasis

Several studies have revealed that physiological concentrations of biotin are required for the normal expression of critical carbohydrate metabolism genes and for glucose homeostasis. However, the different experimental models used in these studies make it difficult to integrate the effects of biotin deficiency on glucose metabolism. To further investigate the effects of biotin deficiency on glucose metabolism, we presently analyzed the effect of biotin deprivation on glucose homeostasis and on pancreatic islet morphology. Three-week-old male BALB/cAnN Hsd mice were fed a biotin-deficient or a biotin-control diet (0 or 7.2 μmol of free biotin/kg diet, respectively) over a period of 8 weeks. We found that biotin deprivation caused reduced concentrations of blood glucose and serum insulin concentrations, but increased plasma glucagon levels. Biotin-deficient mice also presented impaired glucose and insulin tolerance tests, indicating defects in insulin sensitivity. Altered insulin signaling was linked to a decrease in phosphorylated Akt/PKB but induced no change in insulin receptor abundance. Islet morphology studies revealed disruption of islet architecture due to biotin deficiency, and an increase in the number of α-cells in the islet core. Morphometric analyses found increased islet size, number of islets and glucagon-positive area, but a decreased insulin-positive area, in the biotin-deficient group. Glucagon secretion and gene expression increased in islets isolated from biotin-deficient mice. Our results suggest that biotin deficiency promotes hyperglycemic mechanisms such as increased glucagon concentration and decreased insulin secretion and sensitivity to compensate for reduced blood glucose concentrations. Variations in glucose homeostasis may participate in the changes observed in pancreatic islets.     

Taurine supplementation restores glucose and carbachol-induced insulin secretion in islets from low-protein diet rats: involvement of Ach-M3R, Synt 1 and SNAP-25 proteins

Isolated islets from low-protein (LP) diet rats showed decreased insulin secretion in response to glucose and carbachol (Cch). Taurine (TAU) increases insulin secretion in rodent islets with a positive effect upon the cholinergic pathway. Here, we investigated the effect of TAU administration upon glucose tolerance and insulin release in rats fed on a normal protein diet (17%) without (NP) or with 2.5% of TAU in their drinking water (NPT), and LP diet fed rats (6%) without (LP) or with TAU (LPT). Glucose tolerance was found to be higher in LP, compared to NP rats. However, plasma glucose levels, during ipGTT, in LPT rats were similar to those of controls. Isolated islets from LP rats secreted less insulin in response to increasing glucose concentrations (2.8-22.2 mmol/L) and to 100 μmol/L Cch. This lower secretion was accompanied by a reduction in Cch-induced internal Ca(2+) mobilization. TAU supplementation prevents these alterations, as judged by the higher secretion induced by glucose or Cch in LPT islets. In addition, Ach-M3R, syntaxin 1 and synaptosomal associated protein of 25 kDa protein expressions in LP were lower than in NP islets. The expressions of these proteins in LPT were normalized. Finally, the sarcoendoplasmatic reticulum Ca(2+)-ATPase 3 protein expression was higher in LPT and NPT, compared with controls. In conclusion, TAU supplementation to LP rats prevented alterations in glucose tolerance as well as in insulin secretion from isolated islets. The latter effect involves the normalization of the cholinergic pathway, associated with the preservation of exocytotic proteins.     

Insulin and glucagon secretion and the insulin sensitivity of peripheric organs of colony-bred sand rats fed with pellet diet after weaning.

Colony-bred sand rats were fed with rat pellet chow in restricted quantities or ad libitum for 8--10 or 28--31 weeks after weaning. The changes of glucose metabolism were characterized by an intraperitoneal glucose tolerance test. The daily food intake and the average weight gain differed only in the first 5--7 weeks of pellet nutrition. In the impaired glucose tolerance tests of all sand rats the high basal plasma IRI levels were not significantly increased by the grossly enhanced blood glucose concentrations. The insulin secretion of either acutely incubated or for 8 days cultivated isolated pancreatic islets, however, was stimulated already by low (1.7 and 5 mM) glucose concentrations in all diet groups. Otherwise the glucagon secretion of isolated islets was not suppressed by high glucose concentrations. No changes of insulin or glucagon contents of islets were found in the different diet groups. The adipocytes of all animals revealed a complete ineffectiveness of insulin on the glucose utilization to CO2 and triglycerides. The basal glucose conversion to CO2 and glycogen in skeletal muscle and the stimulatory potency of insulin was low and not distinctly different in all groups. In liver glycogen and triglyceride contents as well as gluconeogenic enzyme activities were not influenced by feeding of different quantities of pellet diet at the investigated time points. The time course of the metabolic and clinical alterations demonstrates that the peripheral organs become insensitive to insulin in the first weeks after weaning.     

Early Low Protein Diet Aggravates Unbalance between Antioxidant Enzymes Leading to Islet Dysfunction

Background

Islets from adult rat possess weak antioxidant defense leading to unbalance between superoxide dismutase (SOD) and hydrogen peroxide-inactivating enzymatic activities, catalase (CAT) and glutathione peroxidase (GPX) rending them susceptible to oxidative stress. We have shown that this vulnerability is influenced by maternal diet during gestation and lactation.

Methodology/Principal Findings

The present study investigated if low antioxidant activity in islets is already observed at birth and if maternal protein restriction influences the development of islet antioxidant defenses. Rats were fed a control diet (C group) or a low protein diet during gestation (LP) or until weaning (LPT), after which offspring received the control diet. We found that antioxidant enzymatic activities varied with age. At birth and after weaning, normal islets possessed an efficient GPX activity. However, the antioxidant capacity decreased thereafter increasing the potential vulnerability to oxidative stress. Maternal protein malnutrition changed the antioxidant enzymatic activities in islets of the progeny. At 3 months, SOD activity was increased in LP and LPT islets with no concomitant activation of CAT and GPX. This unbalance could lead to higher hydrogen peroxide production, which may concur to oxidative stress causing defective insulin gene expression due to modification of critical factors that modulate the insulin promoter. We found indeed that insulin mRNA level was reduced in both groups of malnourished offspring compared to controls. Analyzing the expression of such critical factors, we found that c-Myc expression was strongly increased in islets from both protein-restricted groups compared to controls.

Conclusion and Significance

Modification in antioxidant activity by maternal low protein diet could predispose to pancreatic islet dysfunction later in life and provide new insights to define a molecular mechanism responsible for intrauterine programming of endocrine pancreas.     

Low-carbohydrate, high-protein diet affects rhythmic expression of gluconeogenic regulatory and circadian clock genes in mouse peripheral tissues

Recent studies have demonstrated that metabolic changes in mammals induce feedback regulation of the circadian clock. The present study evaluates the effects of a low-carbohydrate high-protein diet (HPD) on circadian behavior and peripheral circadian clocks in mice. Circadian rhythms of locomotor activity and core body temperature remained normal in mice fed with the HPD diet (HPD mice), suggesting that it did not affect the central clock in the hypothalamus. Two weeks of HPD feeding induced mild hypoglycemia without affecting body weight, although these mice consumed more calories than mice fed with a normal diet (ND mice). Plasma insulin levels were increased during the inactive phase in HPD mice, but increased twice, beginning and end of the active phase, in ND mice. Expression levels of the key gluconeogenic regulatory genes PEPCK and G6Pase were significantly induced in the liver and kidneys of HPD mice. The HPD appeared to induce peroxisome proliferator-activated receptor α (PPARα) activation, since mRNA expression levels of PPARα and its typical target genes, such as PDK4 and Cyp4A10, were significantly increased in the liver and kidneys. Circadian mRNA expression of clock genes, such as BMAL1, Cry1, NPAS2, and Rev-erbα, but not Per2, was significantly phase-advanced, and mean expression levels of BMAL1 and Cry1 mRNAs were significantly elevated, in the liver and kidneys of HPD mice. These findings suggest that a HPD not only affects glucose homeostasis, but that it also advances the molecular circadian clock in peripheral tissues.     

Time-restricted feeding entrains daily rhythms of energy metabolism in mice

Energy metabolism, oxygen consumption rate (VO2), and respiratory quotient (RQ) in mice were monitored continuously throughout 12:12-h light-dark cycles before, during, and after time-restricted feeding (RF). Mice fed ad libitum showed robust daily rhythms in both parameters: high during the dark phase and low during the light phase. The daily profile of energy metabolism in mice under daytime-only feeding was reversed at the beginning of the first fasting night. A few days after daytime-only feeding began, RF also reversed the circadian core body temperature rhythm. Moreover, RF for 6 consecutive days shifted the phases of circadian expression patterns of clock genes in liver significantly by 8-10 h. When mice were fed a high-fat (HF) diet ad libitum, the daily rhythm of RQ dampened day by day and disappeared on the sixth day of RF, whereas VO2 showed a robust daily rhythm. Mice fed HF only in the daytime had reversed VO2 and RQ rhythms. Similarly, mice fed HF only in the daytime significantly phase shifted the clock gene expression in liver, whereas ad libitum feeding with HF had no significant effect on the expression phases of liver clock genes. These results suggested that VO2 is a sensitive indicator of entrainment in the mouse liver. Moreover, physiologically, it can be determined without any surgery or constraint. On the basis of these results, we hypothesize that a change in the daily VO2 rhythm, independent of the energy source, might drive phase shifts of circadian oscillators in peripheral tissues, at least in the liver.     

Dietary zinc restriction promotes degeneration of the endocrine pancreas in mice

Zinc is a key component of several proteins, interacting with the pancreatic hormones insulin and amylin. The role of zinc in insulin oligomerization and crystallinity is well established, although the effects of dietary zinc restriction on both energetic metabolism and β-pancreatic hormonemia and morphology remain unexplored. Here we report the effects of dietary zinc restriction on the endocrine pancreas and metabolic phenotype of mice. Nontransgenic male Swiss mice were fed a low-zinc or control diet for 4 weeks after weanling. Growth, glycemia, insulinemia and amylinemia were lower and pancreatic islets were smaller in the intervention group despite the preserved insulin crystallinity in secretory granules. We found strong immunostaining for insulin, amylin and oligomers in apoptotic pancreatic islet. High production of β-pancreatic hormones in zinc-restricted animals counteracted the reduced islet size caused by apoptosis. These data suggest that zinc deficiency is sufficient to promote islet β-cell hormonal disruption and degeneration.     

A low-protein diet during pregnancy prevents modifications in intercellular communication proteins in rat islets

Background

Gap junctions between β-cells participate in the precise regulation of insulin secretion. Adherens junctions and their associated proteins are required for the formation, function and structural maintenance of gap junctions. Increases in the number of the gap junctions between β-cells and enhanced glucose-stimulated insulin secretion are observed during pregnancy. In contrast, protein restriction produces structural and functional alterations that result in poor insulin secretion in response to glucose. We investigated whether protein restriction during pregnancy affects the expression of mRNA and proteins involved in gap and adherens junctions in pancreatic islets. An isoenergetic low-protein diet (6% protein) was fed to non-pregnant or pregnant rats from day 1–15 of pregnancy, and rats fed an isocaloric normal-protein diet (17% protein) were used as controls.

Results

The low-protein diet reduced the levels of connexin 36 and β-catenin protein in pancreatic islets. In rats fed the control diet, pregnancy increased the levels of phospho-[Ser^279/282]-connexin 43, and it decreased the levels of connexin 36, β-catenin and beta-actin mRNA as well as the levels of connexin 36 and β-catenin protein in islets. The low-protein diet during pregnancy did not alter these mRNA and protein levels, but avoided the increase of levels of phospho-[Ser^279/282]-connexin 43 in islets. Insulin secretion in response to 8.3 mmol/L glucose was higher in pregnant rats than in non-pregnant rats, independently of the nutritional status.

Conclusion

Short-term protein restriction during pregnancy prevented the Cx43 phosphorylation, but this event did not interfer in the insulin secretion.     

Disruption of gene expression rhythms in mice lacking secretory vesicle proteins IA-2 and IA-2β

Insulinoma-associated protein (IA)-2 and IA-2β are transmembrane proteins involved in neurotransmitter secretion. Mice with targeted disruption of both IA-2 and IA-2β (double-knockout, or DKO mice) have numerous endocrine and physiological disruptions, including disruption of circadian and diurnal rhythms. In the present study, we have assessed the impact of disruption of IA-2 and IA-2β on molecular rhythms in the brain and peripheral oscillators. We used in situ hybridization to assess molecular rhythms in the hypothalamic suprachiasmatic nuclei (SCN) of wild-type (WT) and DKO mice. The results indicate significant disruption of molecular rhythmicity in the SCN, which serves as the central pacemaker regulating circadian behavior. We also used quantitative PCR to assess gene expression rhythms in peripheral tissues of DKO, single-knockout, and WT mice. The results indicate significant attenuation of gene expression rhythms in several peripheral tissues of DKO mice but not in either single knockout. To distinguish whether this reduction in rhythmicity reflects defective oscillatory function in peripheral tissues or lack of entrainment of peripheral tissues, animals were injected with dexamethasone daily for 15 days, and then molecular rhythms were assessed throughout the day after discontinuation of injections. Dexamethasone injections improved gene expression rhythms in liver and heart of DKO mice. These results are consistent with the hypothesis that peripheral tissues of DKO mice have a functioning circadian clockwork, but rhythmicity is greatly reduced in the absence of robust, rhythmic physiological signals originating from the SCN. Thus, IA-2 and IA-2β play an important role in the regulation of circadian rhythms, likely through their participation in neurochemical communication among SCN neurons.     

Pancreatic insulin secretion in rats fed a soy protein high fat diet depends on the interaction between the amino acid pattern and isoflavones

Obesity is frequently associated with the consumption of high carbohydrate/fat diets leading to hyperinsulinemia. We have demonstrated that soy protein (SP) reduces hyperinsulinemia, but it is unclear by which mechanism. Thus, the purpose of the present work was to establish whether SP stimulates insulin secretion to a lower extent and/or reduces insulin resistance, and to understand its molecular mechanism of action in pancreatic islets of rats with diet-induced obesity. Long-term consumption of SP in a high fat (HF) diet significantly decreased serum glucose, free fatty acids, leptin, and the insulin:glucagon ratio compared with animals fed a casein HF diet. Hyperglycemic clamps indicated that SP stimulated insulin secretion to a lower extent despite HF consumption. Furthermore, there was lower pancreatic islet area and insulin, SREBP-1, PPARgamma, and GLUT-2 mRNA abundance in comparison with rats fed the casein HF diet. Euglycemic-hyperinsulinemic clamps showed that the SP diet prevented insulin resistance despite consumption of a HF diet. Incubation of pancreatic islets with isoflavones reduced insulin secretion and expression of PPARgamma. Addition of amino acids resembling the plasma concentration of rats fed casein stimulated insulin secretion; a response that was reduced by the presence of isoflavones, whereas the amino acid pattern resembling the plasma concentration of rats fed SP barely stimulated insulin release. Infusion of isoflavones during the hyperglycemic clamps did not stimulate insulin secretion. Therefore, isoflavones as well as the amino acid pattern seen after SP consumption stimulated insulin secretion to a lower extent, decreasing PPARgamma, GLUT-2, and SREBP-1 expression, and ameliorating hyperinsulinemia observed during obesity.     

Characterization of Pancreatic Islets in Two Selectively Bred Mouse Lines with Different Susceptibilities to High-Fat Diet-Induced Glucose Intolerance

Hereditary predisposition to diet-induced type 2 diabetes has not yet been fully elucidated. We recently established 2 mouse lines with different susceptibilities (resistant and prone) to high-fat diet (HFD)-induced glucose intolerance by selective breeding (designated selectively bred diet-induced glucose intolerance-resistant [SDG-R] and -prone [SDG-P], respectively). To investigate the predisposition to HFD-induced glucose intolerance in pancreatic islets, we examined the islet morphological features and functions in these novel mouse lines. Male SDG-P and SDG-R mice were fed a HFD for 5 weeks. Before and after HFD feeding, glucose tolerance was evaluated by oral glucose tolerance test (OGTT). Morphometry and functional analyses of the pancreatic islets were also performed before and after the feeding period. Before HFD feeding, SDG-P mice showed modestly higher postchallenge blood glucose levels and lower insulin increments in OGTT than SDG-R mice. Although SDG-P mice showed greater β cell proliferation than SDG-R mice under HFD feeding, SDG-P mice developed overt glucose intolerance, whereas SDG-R mice maintained normal glucose tolerance. Regardless of whether it was before or after HFD feeding, the isolated islets from SDG-P mice showed impaired glucose- and KCl-stimulated insulin secretion relative to those from SDG-R mice; accordingly, the expression levels of the insulin secretion-related genes in SDG-P islets were significantly lower than those in SDG-R islets. These findings suggest that the innate predispositions in pancreatic islets may determine the susceptibility to diet-induced diabetes. SDG-R and SDG-P mice may therefore be useful polygenic animal models to study the gene–environment interactions in the development of type 2 diabetes.     

Protein-restriction diet during the suckling phase programs rat metabolism against obesity and insulin resistance exacerbation induced by a high-fat diet in adulthood

Protein restriction during the suckling phase can malprogram rat offspring to a lean phenotype associated with metabolic dysfunctions later in life. We tested whether protein-caloric restriction during lactation can exacerbate the effect of a high-fat (HF) diet at adulthood. To test this hypothesis, we fed lactating Wistar dams with a low-protein (LP; 4% protein) diet during the first 2 weeks of lactation or a normal-protein (NP; 23% protein) diet throughout lactation. Rat offspring from NP and LP mothers received a normal-protein diet until 60 days old. At this time, a batch of animals from both groups was fed an HF (35% fat) diet, while another received an NF (7% fat) diet. Maternal protein-caloric restriction provoked lower body weight and fat pad stores, hypoinsulinemia, glucose intolerance, higher insulin sensitivity, reduced insulin secretion and altered autonomic nervous system (ANS) function in adult rat offspring. At 90 days old, NP rats fed an HF diet in adulthood displayed obesity, impaired glucose homeostasis and altered insulin secretion and ANS activity. Interestingly, the LP/HF group also presented fat pad and body weight gain, altered glucose homeostasis, hyperleptinemia and impaired insulin secretion but at a smaller magnitude than the NP-HF group. In addition, LP/HF rats displayed elevated insulin sensitivity. We concluded that protein-caloric restriction during the first 14 days of life programs the rat metabolism against obesity and insulin resistance exacerbation induced by an obesogenic HF diet.