This study examines the influence of increasing household availability of sodas and cookies on the effects of an intervention to promote the consumption of fruits and vegetables. The study analyzed data from 70 families living in low-income communities in the city of Rio de Janeiro, Brazil, selected in a stratified probabilistic sample, and who completed a 30-day food record before and after the intervention. The intervention contributed to a significant increase in the household availability of fruit and vegetables (+2.7 p.p.; 95%CI: 1.5; 4.0), contrary to the trend towards stagnation of such availability in the general population in Brazil. Meanwhile, the purchase of sodas and cookies, which was not the intervention's target, mirrored the upward trend in the consumption of these products (+5.8 p.p.; 95%CI: 3.3; 8.4). Families that increased their purchase of sodas and cookies showed lower increases, or even decreases, in the purchase of fruits and vegetables (p < 0.05), and had nearly fourfold lower odds of experiencing any increase in the household availability of fruits and vegetables.