In this study, a two-stage, low-consistency (LC) refining process at the Holmen Braviken paper mill in Sweden was examined to evaluate the relationship between energy input, fibre distributions, and pulp properties, including handsheet properties. The LC refiners used thermo-mechanical pulp based on 100 % Norway spruce, with two specific energy levels: "low" (approximate to 80 kWh/adt) or "high" (approximate to 100 kWh/adt). All four permutations of these settings were examined. Overall, higher refining efficiency (measured by the increase in tensile index per applied energy) was observed in the first LC refiner stage than in the second. To further explore the impact of LC refining, pulp particle distributions were investigated. Samples from before, between and after the two LC stages were analysed using an optical fibre analyser, which provided detailed data on length-width-curl-fibrillation distributions. The impact of LC refining on these distributions was quantified using Kolmogorov-Smirnov statistics, highlighting statistically significant changes observed in the length and curl distributions. We investigated the correlation between energy input into the LC refiners and the impact on fibre distributions and handsheet properties. These insights underscore the effectiveness of our analytical approach and its potential for refining process control in mechanical pulping, offering a method for more targeted and efficient adjustments.