Objectives: Physical inactivity and diet are often studied in isolation regarding metabolic function. However, they may interact to attenuate or accelerate the development of metabolic dysfunction, which demands further research. The project aims to provide more information about the interaction of physical inactivity and processed meat- and alternative protein-based diets on chronic disease development.
Methods: Small mouse cages (SMCs) were employed to model physical inactivity in mice. The SMC reduces the physical activity of mice and is an analog of step reduction in humans. The processed meat diet was powdered, lyophilized pork sausages (PM), and the alternative protein-based diet was a mixture of cricket powder and lyophilized shelled hemp seeds at a 1:1 ratio (AP). Both diets contain the equivalent amount of macronutrients, fiber, and basal levels of essential micronutrients, and provide 48% energy from fat. At 5-week-old, C57BL/6 mice were randomized into 6 groups for 4 weeks: 1) standard cage + AIN-93G standard diet; 2) standard cage + PM; 3) standard cage + AP; 4) SMC + AIN-93G; 5) SMC + PM; and 6) SMC + AP.
Results: SMC-induced physical inactivity resulted in adiposity, inflammation, glucose intolerance, and reduced muscular strength compared to the mice housed in the standard cages, as evidenced by greater body weight gain and fat mass, elevated plasma level of IL-1β and TNF-α, lower blood glucose concentration during GTT, and reduced grip strength, respectively. Importantly, the interaction of physical inactivity and diet further impacted these metabolic outcomes, e.g., the combined effect showed greater influence on blood glucose concentration than each entity alone. Further analyses on muscle, adipose tissue, and fecal samples are underway to understand the potential beneficial effects of alternative proteins on physical inactivity-associated adverse metabolic outcomes.
Conclusions: The interaction between different dietary patterns and physical inactivity could be a target for nutritional therapy, which warrants further investigation. The potential beneficial effect of replacing processed meat with healthier alternative proteins also requires more research in preclinical and clinical studies.
Funding Sources: Miami University's College of Education, Health, and Society Interdisciplinary Research Seed Grant
