The aim of this work was to evaluate the effects of flaxseed flour in the intake on adiposity and femur structure of the lactating rats during the post-weaning period. After weaning, the lactating rats were divided into control (C, n = 6) and experimental (F, n = 6) groups treated with a diet containing flaxseed flour. Serum hormone and fatty acids composition, morphology of intra-abdominal adipocytes, computed tomography and biomechanical analyses of femur were determined. Food intake, body mass and hormone analysis have shown similar results. The F group showed the following (p < 0.05): lower arachidonic acid (-60%), total polyunsaturated fatty acids (-30%) and retroperitoneal adipocytes (-36%) area. Higher radiodensity of femoral head region (+29%) and higher maximum force (+18%), breaking strength (+18%) and rigidity (+31%). Fatty acid composition of flaxseed flour decreased the area of adipocytes and improved the bone quality, which may be associated with lower serum levels of arachidonic acid levels, during the post-weaning period.

Flaxseed flour has been described as an excellent alpha-linolenic acid source. This study was designed to evaluate the effects of flaxseed flour on body adiposity and bone health in rats fed a flaxseed flour diet during lactation until 90 days. At birth, male Wistar rats were randomly assigned to control (C) and experimental (FF) groups, whose dams were treated with a control or flaxseed flour diet, respectively, during lactation. At 21 days, pups were weaned and fed a control and experimental diet until 90 days. Food intake, body mass and length were evaluated during a 21-90 day period. At 90 days, composition by dual-energy X-ray absorptiometry, serum hormonal profile, intra-abdominal fat mass, and lumbar vertebra and femur analyses was determined. Differences were deemed significant at p < 0.05. The FF group displayed the following (P < 0.05): a higher total lean mass (+7%), a lower total (-16%) and intra-abdominal (-24%) fat mass, a smaller adipocyte area (-30%), a higher femoral mass (+5%), bone mineral density (+5%) and radiodensity (+20%), and a higher maximum force (+10%) and breaking strength (+11%). The flaxseed flour diet displayed functional properties related to body growth maintenance associated with a lower risk of developing metabolic alterations, obesity and bone fragility.