Introduction: Overfeeding in early life can persistently modify consumption and body weight. Adoption of exercise is one useful strategy to prevent excessive weight gain. Objective: to assess body growth and feed efficiency in rats from reduced litters during lactation. Methods: On day 3 of life, litters were formed with 4 (GN4) or 10 animals (GN10) (n = 25). When weaned, Wistar male rats were kept in individual cages and at day 60 (± 2) they were divided into sedentary (SED) and exercised (NAT -swimming), forming thus four groups: GN4SED; GN10SED; GN4NAT and GN10NAT. Assessment consisted of weight, weight gain and specific rate of weight gain, epididymal fat, Body Mass and Lee Indices, consumption and feed efficiency, blood glucose and lactemia. Results: At day 21, GN4 had body weight 52% above GN10 (P = 0.001). However, at days 30 and 60, their weight was not different. At the end of the period, GN10NAT showed lower weight (356.82 ± 23.04) that GN10SED (409.28 ± 17.30), but GN4NAT was heavier (417.85 ± 37.91) than GN4SED (413.69 ± 57.45) and GN10NAT. GN4 presented higher rate of weight gain during lactation, but slower after weaning. Regardless of litter size, rate of weight gain reduces as age progresses. At the end of this period, blood glucose, total and relative epididymal fat, and Lee and BMI indices did not differ between groups. Pre and post-exercise lactate values are consistent with moderate effort. In periadolescence, GN4 showed lower food intake, but with no differences in adulthood. Conclusion: Reduced litter during lactation did not affect body weight or food intake persistently. However, the swimming protocol was effective in reducing weight gain in control animals, but not in animals from reduced litters.

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These findings suggest that neonatal serotonin reuptake inhibition is associated with better adaptation to hypercaloric diet in adult rats.

The serotoninergic system controls key events related to proper nervous system development. The neurotransmitter serotonin and the serotonin transporter are critical for this control. Availability of these components is minutely regulated during the development period, and the environment may affect their action on the nervous system. Environmental factors such as undernutrition and selective serotonin reuptake inhibitors may increase the availability of serotonin in the synaptic cleft and change its anorectic action. The physiological responses promoted by serotonin on intake control decrease when requested by acute stimuli or stress, demonstrating that animals or individuals develop adaptations in response to the environmental insults they experience during the development period. Diseases, such as anxiety and obesity, appear to be associated with the body’s response to stress or stimulus, and require greater serotonergic system action. These findings demonstrate the importance of the level of serotonin in the perinatal period to the development of molecular and morphological aspects of food intake control, and its decisive role in understanding the possible environmental factors that cause diseases in adulthood.

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Maternal nutrition is an environmental determinant for offspring growth and development, especially in critical periods. Nutritional imbalances during these phases can promote dysregulations in food intake and feeding preference in offspring, affecting body composition. The aim of this review is to summarize and discuss the effects of maternal high-fat diet (HFD) on offspring feeding behavior and body composition. A search was performed in the PUBMED, SCOPUS, Web of Science, and LILACS databases. Inclusion criteria were studies in rodents whose mothers were submitted to HFD that assessed outcomes of food or caloric intake on offspring and food preference associated or not with body weight or body composition analysis. At the end of the search, 17 articles with the proposed characteristics were included. In these studies, 15 articles manipulated diet during pregnancy and lactation, 1 during pregnancy only, and 1 during lactation only. Maternal exposure to a HFD leads to increased food intake, increased preference for HFDs, and earlier food independence in offspring. The offspring from HFD mothers present low birthweight but become heavier into adulthood. In addition, these animals also exhibited greater fat deposition on white adipose tissue pads. In conclusion, maternal exposure to HFD may compromise parameters in feeding behavior and body composition of offspring, impairing the health from conception until adulthood.

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This study investigated the effects of maternal separation on the feeding behavior of rats. A maternal separation model was used on postnatal day 1 (PND1), forming the following groups: in the maternal separation (MS) group, pups were separated from their mothers each day from PND1 to PND14, whereas in the control (C) group pups were kept with their mothers. Subgroups were formed to study the effects of light and darkness: control with dark and light exposure, female and male (CF and CM), and maternal separation with dark and light exposure, female and male (SDF, SDM, SLF and SLM). Female rats had higher caloric intake relative to body weight compared with male controls in the dark period only (CF=23.3±0.5 v. CM=18.2±0.7, P<0.001). Macronutrient feeding preferences were observed, with male rats exhibiting higher caloric intake from a protein diet as compared with female rats (CF=4.1±0.7, n=8 v. CM=7.0±0.5, n=8, P<0.05) and satiety development was not interrupted. Female rats had a higher adrenal weight as compared with male rats independently of experimental groups and exhibited a higher concentration of serum triglycerides (n=8, P<0.001). The study indicates possible phenotypic adjustments in the structure of feeding behavior promoted by maternal separation, especially in the dark cycle. The dissociation between the mother's presence and milk intake probably induces adjustments in feeding behavior during adulthood.