Effects of replacing meat and fish with pulse intake on circulating fibroblast growth factor-23 levels during a 12-week dietary weight-loss intervention using the Four-Food-Group Point Method: a pilot randomized controlled study.

Fibroblast growth factor-23 (FGF23) is a phosphaturic hormone secreted by the bone in response to dietary phosphate intake. High circulating FGF23 levels is an early sign of cardiovascular disease in individuals with obesity. This randomized controlled trial investigated the effects of replacing meat and fish with pulse intake on circulating FGF23 levels during a dietary weight-loss intervention. Sixteen middle-aged and older individuals with overweight and obesity (63.7 ± 5.1 years of age) were randomly assigned to control and plant groups. All participants attended a dietary weight-loss class once per week for 12 weeks. Participants in the plant group replaced meat and fish with pulse intake. Circulating FGF23 levels were measured before and after the intervention. Both groups showed reductions in body weight (control: 73.3 kg to 66.9 kg, plant: 78.8 kg to 73.1 kg, P < 0.001 for time effect). Plant-based protein intake was significantly higher in the plant group than in the control group (control: 7.3% of energy to 7.7% vs. plant: 7.0% of energy to 9.2%; P = 0.002 for group × time effect). However, the circulating FGF23 levels did not change in either group. Our results suggest that dietary weight-loss intervention promoting plant-based protein intake does not decrease circulating FGF23 levels. As this trial is one of the few to examine the effects of dietary weight-loss interventions on circulating FGF23 levels, additional intervention studies are needed. The protocol was registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN000048081; registered on 6/18/2022).