Background
Excessive salt consumption is associated with hypertension and other cardiovascular diseases, however, its link to metabolism and role in the development of obesity remains unclear. In this study, we investigated the influence of salt on the development of obesity, when given in combination with a high-fat diet (HFD).
Methods
Age-matched C57BL/6JAus male mice were fed a chow diet, a chow supplemented with salt (Chow+salt), HFD, or HFD supplemented with salt (HFD+salt), for 4-weeks. Metabolic characterisation was performed, including assessment of body weight, body composition, food intake, water intake, energy expenditure by metabolic cages, temperature measurements, as well as glucose and insulin tolerance tests. qPCR was conducted on adipose tissues for thermogenic markers.
Results
Short-term salt intake under both chow and HFD conditions showed reductions in body weight (BW) gain, owing to reductions in both fat mass and lean mass, with minor contributions from reductions in bone mineral content. These reductions were independent of food intake and physical activity. In addition, 24-hour respiratory quotient for HFD+salt treated mice was significantly lower compared to HFD alone mice at 2-weeks, suggesting an increase in fat oxidation due to salt treatment. Interestingly, core temperatures being significantly elevated in salt-treated mice, which was associated with significant upregulation of thermogenic markers in adipose tissues. Glucose and insulin tolerance tests were significantly altered with salt treatment.
Conclusion
Our data show short short-term salt intake reduces the progression of diet-induced obesity, primarily due to a reduction in both fat mass and lean mass. This study, for the first time, unveils an unrecognized physiological role of salt in metabolism, adipose tissue physiology and energy balance regulation. Importantly, the findings from this research contributes to our understanding of the multifaceted role of salt in both cardiovascular disease and metabolism.
1st year PhD Candidate