The effect of birth weight on low-energy diet-induced changes in body composition and substrate-energy metabolism in obese women.

OBJECTIVE: The objective of this study was to examine the association of birth weight (BW) with body composition, resting metabolic rate (RMR), nonprotein respiratory quotient (NPRQ), and insulin sensitivity changes after a 12-week diet intervention program. METHODS: A total of 78 obese (body mass index [BMI] 34.0 ± 2.8) women aged 36.7 ± 7 years volunteered to participate in a 12-week diet intervention program. We assessed body fat mass (FM), lean mass (LM), and bone mass (BM; measured by dual energy x-ray absorptiometry), RMR (measured by indirect calorimetry), fasting plasma glucose, and insulin before and after the intervention. We calculated BMI, FM to LM ratio (FM/LM), and HOMA-IR. BW and gestational age were self-reported, and the BW Z-score was calculated. RESULTS: At baseline, the BW Z-score was positively associated with LM (p < 0.01) and RMR (p < 0.05). The BW Z-score was significantly associated with diet-induced FM (p < 0.05) and FM/LM ratio changes (p < 0.01) independently of potential confounders including weight loss. The BW Z-score was not associated with diet-induced RMR or insulin resistance changes. CONCLUSIONS: Lower birth weight is associated with lower LM and RMR in obese women and could program a lower FM loss achievement after an energy-restriction diet intervention.

Role of ß2-adrenergic receptor polymorphisms on body weight and body composition response to energy restriction in obese women: preliminary results.

We investigated the role of common ß2-adrenergic receptor (ADRB2) rs1042714 (Gln27Glu) and rs1042713 (Arg16Gly) polymorphisms on body weight and body composition response to 12-week energy-restricted diet in women. The study comprised 78 Spanish obese (BMI: 34.0 ± 2.8 kg/m²) women (age: 36.7 ± 7 years). We measured (before and after the dietary intervention) weight and height, and BMI calculated. Moreover, body fat mass and lean mass (LM) were measured by dual energy X-ray absorptiometry. We observed an interaction effect between the Gln27Glu polymorphism and diet-induced changes on body weight (P = 0.006), BMI (P = 0.004), and LM (P = 0.001). Women carrying the Glu allele had a greater reduction in body weight than non-Glu allele carriers (9.5 ± 2.9 vs. 7.0 ± 3.5%, respectively, P = 0.002). Moreover, women with the Glu allele lost more LM than the Gln27Gln group (5.9 ± 2.7 vs. 4.0 ± 2.7%, respectively, P = 0.001). We did not find any significant interaction effect between the Arg16Gly polymorphism and diet-induced changes on the outcome variables (all P > 0.1). The results suggest that the ADRB2 Gln27Glu polymorphism has a modulating effect on diet-induced changes on body weight and body composition, and should be considered in future obesity treatments. These findings should be taken as preliminary and be replicated in further energy restriction studies with larger sample sizes.

Microencapsulation of a probiotic and prebiotic in alginate-chitosan capsules improves survival in simulated gastro-intestinal conditions.

Chitosan was used as a coating material to improve encapsulation of a probiotic and prebiotic in calcium alginate beads. Chitosan-coated alginate microspheres were produced to encapsulate Lactobacillus gasseri (L) and Bifidobacterium bifidum (B) as probiotics and the prebiotic quercetin (Q) with the objective of enhancing survival of the probiotic bacteria and keeping intact the prebiotic during exposure to the adverse conditions of the gastro-intestinal tract. The encapsulation yield for viable cells for chitosan-coated alginate microspheres with quercetin (L+Q and B+Q) was very low. These results, together with the study about the survival of microspheres with quercetin during storage at 4 degrees C, demonstrated that probiotic bacteria microencapsulated with quercetin did not survive. Owing to this, quercetin and L. gasseri or B. bifidum were microencapsulated separately. Microencapsulated L. gasseri and microencapsulated B. bifidum were resistant to simulated gastric conditions (pH 2.0, 2h) and bile solution (3%, 2h), resulting in significantly (p<0.05) improved survival when compared with free bacteria. This work showed that the microencapsulation of L. gasseri and B. bifidum with alginate and a chitosan coating offers an effective means of delivery of viable bacterial cells to the colon and maintaining their survival during simulated gastric and intestinal juice.