Aggressive behaviours and adaptations of sows to sudden events during gestation could influence their nutritional requirements. The purpose of this study was to evaluate the impact of induced feed competition on the activity and social behaviour of gestating sows. The experiment included 31 sows, observed during the first 36 h of a “baseline” period (i.e. two feeders available in the pen) and a “test” period, in the following week, with induced feed competition (i.e. closing one of the two feeders). Skin lesions were visually recorded every week. Feeding behaviour was automatically recorded by the feeders. Video recordings allowed observers to manually identify continuously each sow’s position, occupation, and social interactions. The influence of the period (baseline vs test) and parity (primiparous vs multiparous) on these measurements was analysed using RStudio by applying a linear mixed-effects model that considered sows as a random effect. The number of non-feeding visits to the feeder was lower during the test period than during the baseline period (2.3 vs 4.7 visits/d, respectively; P < 0.01), while the number of feeding visits did not differ between periods (1.1 visit/d). Sows stood in front of the feeder longer during the test period than during the baseline period (98.5 vs 40.1 min/d, respectively; P < 0.01). Despite more negative social interactions during the test period (i.e. head butts and bites, P < 0.01), the number of skin lesions did not differ between periods. To conclude, the physical activity, and feeding and social behaviours were influenced by feed competition and led to a mean increase of 5% in energy requirements of gestating sows.