A high-protein plant-based vs omnivorous diet modulates markers of cardiometabolic health without altering micronutrient status during resistance training

Abstract Purpose Hypercaloric, high-protein diets are advocated to maximise resistance training induced skeletal muscle hypertrophy but can be associated with impairments in cardiometabolic health. Alternatively, vegan diets are suggested to improve indices of cardiometabolic health but can increase likelihood of specific micronutrient deficiencies. We aimed to investigate the impact of consuming a hypercaloric, high-protein plant-based diet, compared with an isoenergetic and isonitrogenous omnivorous control diet, during high-volume resistance training on indices of cardiometabolic health and micronutrient status. Methods We performed a secondary analysis in 22 healthy young adults (age: 24±1 y, BMI: 23±1 kg·m²) who undertook a 10-week high-volume whole-body resistance exercise program (5-days/week) while consuming a hypercaloric, high-protein (∼2 g·kg bm⁻¹·day⁻¹), omnivorous (OMNI: n=12) or mycoprotein-rich plant-based (PB: n=10) diet. Fasting venous blood samples were collected pre- and post- intervention to assess circulating glucose, insulin, lipid (using quantitative, targeted NMR-based metabonomics) and micronutrient statuses. Results Plasma glucose concentrations remained unchanged (P>0.05), whereas serum insulin concentrations increased in OMNI only (P<0.05), resulting in an increased HOMA-IR index in OMNI (from 2.4±0.2 to 2.9±0.2; P<0.05) but not PB (from 2.3±0.1 to 2.2±0.1; P>0.05). The plasma lipidome, serum vitamin B12, vitamin D and calcium concentrations remained unaltered (all P>0.05) throughout the intervention period, but fasting serum ferritin concentrations decreased to equivalent extents in both groups (P<0.05). Conclusion Adhering to a hypercaloric, mycoprotein-rich, plant-based diet during high-volume resistance-training positively influences markers of cardiometabolic health compared to an isoenergetic and isonitrogenous omnivorous diet, without compromising micronutrient status.