The physio-metabolic effects of time-restricting liquid sugar intake to six-hour windows during the mouse active phase: The effects of active phase liquid sugar consumption

Obesity is a major public health concern and overconsumption of unhealthy fats and sugary beverages are contributing factors. Time-restricted feeding can reduce obesity-associated pathophysiological parameters by limiting the time of food consumption; however, the effects of time-restricted sugary water consumption are unknown. To examine whether liquid calorie restriction impacts metabolic health, we measured metabolic parameters in mice provided liquid sugar at various intervals during the active phase. The control (Con) group received tap water, the adlibitum fructose-glucose (ALFG) group received ad libitumsugar water and the early fructose-glucose (EFG) and late fructose-glucose (LFG) groups received liquid sugar during the first and last six hours of the active period, respectively. Each group was given free access to chow. Zeitgeber time (ZT) notation was used to set all experimental time points to lights on as ZT 0. The ALFG group exhibited elevated body and adipose tissue weights compared to the other groups and increased hepatic steatosis compared to the Con group. The ALFG group consumed more calories than the other groups during ZT 6-11, indicating that this window may be critical in the promotion of weight gain from liquid sugar consumption. The EFG group exhibited higher levels of energy expenditure than the Con and LFG groups during the first half of the active period (ZT 12-17); however, there was no difference among the groups during the second half of the active period (ZT18-23). In contrast, the EFG group exhibited lower respiratory exchange ratio than other groups during the inactive period as well as the second half of the active period, indicating that the EFG group had greater metabolic flexibility and utilized lipids when carbohydrates from liquid sugar were not available. Additionally, the EFG group was more insulin tolerant than the ALFG and Con groups. Our results support the hypothesis that time-restricted liquid calorie restriction aids in reducing the detrimental metabolic effects of sugary drink consumption.