Weight maintenance diets prevent short‐term physical inactivity‐induced glycemic dysregulation in young healthy subjects

Background Reduced physical activity is generally associated with disruptions in glucose metabolism and increased accumulation of adiposity. However, whether these adverse effects of physical inactivity manifest when individuals are maintained in energy balance is unknown. Thus, this study examined whether weight maintenance diets prevent physical inactivity‐induced metabolic dysfunction in healthy active adults. Design Ten lean young adults (24±1 year; 25±1 kg/m 2 ) consumed a control (64% carbohydrate, 20% fat, 16% protein) and higher‐protein diet (50% carbohydrate, 20% fat, 30% protein) during ten days of reduced ambulatory activity (>10,000 → ~5,000 steps/day) in a randomized cross‐over design. To mimic the typical Western lifestyle, a subset of male subjects (n=5) completed a 3 rd ten‐day physical inactivity trial while consuming 35% excess of their basal energy requirements. Results During inactivity, daily steps and activity‐associated energy expenditure were decreased by ~65% ( P <0.05) and this led to a reduction in maximal aerobic capacity (−1.8±0.7 ml/kg/min, P =0.004), independent of diet conditions. Fat free mass tended to decrease following inactivity ( P =0.06), despite no change in body fat percentage or fat mass. Fasting glucose, but not fasting insulin levels, were lowered by physical inactivity, with no differences between diet conditions. Both diets prevented physical inactivity‐induced disruptions in postprandial glucose, insulin, and nonesterified fatty acids in response to a 75‐g oral glucose load (AUC, P >0.05). Overfeeding + physical inactivity increased body weight, body fat percentage, and fat mass ( P >0.05). Moreover, fasting glucose, insulin, and 2‐hour postprandial glucose and insulin levels were significantly elevated ( P <0.05). Surrogate markers of insulin sensitivity (QUICKI) and insulin resistance (HOMA‐IR) were decreased and increased, respectively after overfeeding + inactivity, despite no changes in blood lipid concentrations. Conclusions Metabolic disruptions associated with physical inactivity are absent in healthy subjects consuming weight maintenance diets. These findings suggest that small changes in feeding behavior aimed at preventing weight gain is a viable strategy to protect against inactivity‐induced metabolic dysfunction. Support or Funding Information American Egg Board (#00050021 to NCW; JAK, sponsor) This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .