Time-restricted eating (TRE) has gained increased attention due to the possibility to induce weight loss and improve cardiometabolic health as a result of the purported alignment of circadian rhythm. However, since TRE is often reported to cause a spontaneous reduction of calories, it is not well understood if these health benefits are due to weight loss, circadian rhythm alignment, or a combination of the two. Furthermore, while weight loss can improve cardiometabolic health, it can also induce bone loss, which is problematic in older women who are at a higher risk of fracture. Interestingly, both bone turnover and the gut microbiota are responsive to diurnal variations, such as meal timing, and alterations in the gut microbiota have been associated with differences in bone health. In rodent models, caloric restriction can alter the gut microbiota composition with further alterations shown due to time-restricted eating. This suggests that time-restricted eating could affect bone health, which may be partially mediated by changes in the gut microbiota. Also, lifestyle patterns affects both the microbiota and bone. This randomized controlled trial will use behavior modification to examine TRE plus caloric restriction (CR) to achieve an evening energy deficit compared to CR alone on body weight, the gut microbiota, and bone health in older women who are overweight or obese.
In the Time-Restricted Eating: Microbiome and Bone (TREMBO) study, the primary goal is to determine the effect of time-restricted eating with caloric restriction compared to caloric restriction alone on body weight, the gut microbiota, and bone health in older women who are overweight or obese.