Using swine as a model for humans, this study was conducted to determine if replacing the sugar present in the average American diet (SUG) with ground beef (GB) would alter developmental body composition, onset of puberty, and risk factors for obesity-related metabolic disorders. Twenty-four Berkshire gilts of common age and sire line were obtained at weaning, assigned to one of two dietary treatments (SUG vs. GB), and pair-fed at an average of 3.7 % body weight for 93 d. Over time, GB gilts had superior body weight gain (P < 0.01), larger cross-sectional longissimus muscle area (P < 0.0001), less subcutaneous fat depth (P = 0.0005), and greater percentage lean body mass (P < 0.0001) than SUG. Reproductive tracts were prepubertal across treatments; however, follicular development was observed in GB gilts. Sodium, hematocrit, hemoglobin, and insulin-like growth factor 1 were higher and ionic calcium lower for GB compared to SUG gilts.