Background: To examine the effect of protein-focused (PRO, 1.14 g/kg/day) and carbohydrate-focused (CHO, ∼2.2 g/kg/day) diets (∼1600 kcals) combined with 10 weeks of circuit exercise training in sedentary overweight/obese women (N = 661, age 46 ± 11 years) on metabolic syndrome (MetS).
Methods: We retrospectively analyzed eight exercise training studies performed from 2002-2014. Primary (MetS), secondary (MetS z-scores and individual MetS components), and tertiary outcomes [body mass index (BMI) by WHO cut points] were analyzed using chi-square, GLM, and McNemar's tests.
Results: Both groups experienced significant weight loss, improvements in fitness, and reductions in MetS prevalence from baseline to follow-up (PRO: 49% to 42%, CHO: 42% to 36%, both P < 0.01). MetS z-score improvement (∼66.5%) was similar for both groups with no significant between-group differences noted. There were also no significant differences for individual component features between groups for the following: waist circumference (-0.28 ± 0.02 vs. -0.28 ± 0.025 cm, P = 0.97), glucose (-0.07 ± 0.03 vs. -0.08 ± 0.04 mM, P = 0.87), triglycerides (-0.16 ± 0.04 vs. -0.09 ± 0.04 mM, P = 0.20), high-density lipoprotein cholesterol (-0.21 ± 0.03 vs. -0.19 ± 0.04 mM, P = 0.68), and systolic BP (-0.16 ± 0.4 vs. -0.24 ± 0.05 mmHg, P = 0.26). Diastolic BP showed a minor advantage for the PRO group (-0.14 ± 0.05 vs. -0.30 ± 0.05 mmHg P = 0.02). When stratified by BMI, those with morbid obesity did not show a significant improvement in MetS while following a PRO-focused diet; however, caution is warranted given the exploratory nature of this analysis.
Conclusions: Our findings suggest that a low-moderate calorie diet partitioned for CHO and PRO preference is equally effective when combined with a structured exercise program for reducing the prevalence of MetS prevalence in overweight/obese women.