Maternal Protein Restriction and Branched-Chain Amino Acid Supplementation Differentially Affect Maternal Energy...

The increasing prevalence of low-birth-weight (LBW) offspring from obese mothers underscores the need for dietary strategies to mitigate the transgenerational propagation of metabolic diseases.

We determined whether dietary protein restriction under obesogenic conditions altered maternal energy balance and led to LBW offspring and whether branched-chain amino acid (BCAA) supplementation improved maternal energy balance and mitigated weight and craniofacial skeletal deficits in offspring.

High-fat-fed obese pregnant Sprague Dawley rats (~8-10 weeks of age, n = 8-11/group) were randomized in study 1 to control high-fat diet (20% protein; HFD), low-protein diet (LP; 5% protein), and LP + BCAA diet (100% BCAA requirements) and in study 2 to control HFD (20% protein), LP (10% protein), and LP + 2BCAA diet (200% BCAA requirements). Post-weaning offspring were fed HFD until 8 weeks of age.

Protein restriction promoted hyperphagia and energy expenditure, whereas BCAA supplementation attenuated such hyperphagic effects in pregnancy but not in lactation. Protein restriction reduced maternal body weight in lactation, and although BCAA supplementation did not reverse the weight loss, it enhanced insulin sensitivity and paradoxically reduced offspring survival. Maternal protein restriction reduced offspring body weight and craniofacial bone growth that persisted into adulthood, but BCAA supplementation did not rescue such deficits.

Maternal protein restriction in obese dams enhanced maternal energy expenditure but impaired offspring growth and development. Although BCAA supplementation improved maternal energy balance, it was insufficient to reverse the adverse effects of maternal protein restriction on offspring growth under obesogenic conditions.