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.

The goal of this study was to evaluate the effect of the food availability period on body weight, self-selection of macronutrients, adiposity, lipoprotein, and serum glucose profiles without changing energy intake. Young male rats were divided into 2 groups according to the availability of food during the light and dark phases of the cycle, forming 2 groups: control group (CG) and group with inverted feeding pattern (IFPG). Before inversion of food availability on the 80th day, circadian food intake was measured every 4 h over 24 h during 3 days. The glycemic curve, an oral test for glucose tolerance, and self-selection of macronutrients were evaluated. Blood samples were collected for analysis of fasting glucose, triglycerides, and total cholesterol fractions. The IFPG showed an increase in fasting glucose in the dark phase of the cycle, changes in the glycemic curve, and oral glucose tolerance test. It also showed increased abdominal and liver fat and distinct choice of macronutrients compared with the CG. A change in the availability of food according to the phase of the circadian cycle produces changes in glucose and feeding circadian rhythm culminating in increased abdominal and hepatic fat. These effects can increase the risk of metabolic disorders and installation of chronic diseases.

OBJECTIVE: The present study assessed the pregnancy and lactation performances of rats fed an experimental diet based on the foods listed in the Family Budget Survey (Pesquisa de Orçamento Familiar) 2002/2003 and the impact of said diet on the growth and development of the pups until weaning. METHODS: Wistar (n=12) rats were randomly divided into two groups: a control group (control group, n=6) fed a commercial chow (Labina®, Brazil) and an experimental group (n=6) fed the Family Budget Survey diet during the entire pregnancy and lactation period. All animals had free access to food and water during the entire study period. RESULTS: The Family Budget Survey diet increased the duration of pregnancy (control group=21.00±0.00; POFG=21.57±0.55, p=0.025) and made the dams lose weight during the lactation period (control group=27.92±18.47g; POFG=-15.66±16.90g). The Family Budget Survey group presented low food, energy and nutrient intakes during pregnancy, which became even lower during lactation. Pups from Family Budget Survey dams presented lower body weight at weaning (control group=52.38±4.49g; POFG=39.88±2.78g, p=0.001) and lower nose-to-anus length (control group= 117.37±0.64mm; POFG=125.62±0.96mm, p=0.001). However, some physical milestones and reflexes occurred earlier, such as the placing response reflex [control group= 12.00 (9.00-15.00) days; POFG=9.50 (9.00-14.00) days] aerial righting reflex [control group=18.00 (17.00-20.00) days; POFG=16.00 (13.00-18.00) days] and unfolding of the external ear [control group=3.00 (3.00-3.00) days; POFG=2.00 (2.00-3.00) days]. CONCLUSION: The Family Budget Survey diet seems to be more detrimental to the physical growth of the pups than to their brain growth, according to the assessed reflexes and physical milestones and measures. This may be due to the low protein content of the diet for rat reproduction and growth combined with adequate fat and essential fatty acid contents. Providing an adequate amount of protein to the Family Budget Survey diet may normalize pup growth.

Maternal low-energy diet shows discernible short- and long-term effects on offspring, and this is dependent on the time of perinatal period.

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