This study aimed to evaluate the influence of different intermittent fasting regimens on metabolic parameters in healthy rats and compare them with caloric restriction. A total of fifty adult male Wistar rats (±90 days old) were randomised into 5 groups: control group (CON), caloric restriction group (CR), time-restricted feeding group (TRF), alternate-day fasting (ADF) group and alternate-day modified fasting group (ADMF). ADF and ADMF stood out for improving the metabolic parameters in healthy rats by presenting improvements in glucose parameters, greatest weight loss (ADF v. CON: −16·50 (sd 6·16) g; effect size = −5·34; 95 % CI: −7·05, −3·04; P < 0·001; ADMF v. CON: –21·88 (sd 6·66) g; effect size = −5·83; 95 % CI: −7·66, −3·36; P < 0·001) and higher HDL (ADF v. CON: 141·50 (sd 10·17) mg/dl; effect size = 3·03; 95 % CI: 1·01, 4·45; P < 0·001; ADMF v. CON: 133·10 (sd 5·94) mg/dl; effect size = 3·37; 95 % CI: 1·22, 4·86; P = 0·004). Additionally, ADMF presented a smaller adipocyte area among the fasting regimens (13·92 (sd 2·06) area/µm2; effect size = −4·20; 95 % CI: −5·45, −2·66; P < 0·001 v. CON), in addition to presenting muscle fibre hypertrophy (71·20 (sd 5·16) area/µm2; effect size = 2·93; 95 % CI: 1·57, 4·05; P < 0·001 v. CON), followed by ADF (adipocyte area: 19·25 (sd 0·87) area/µm2; effect size = −2·19; 95 % CI: −3·12, −1·12; P = 0·003 v. CON; muscle fibre: 53·80 (sd 6·61) area/µm2; effect size = 2·93; 95 % CI: 1·57, 4·05; P = 0·566 v. ADMF). The ADF and ADMF groups were more effective among the intermittent fasting regimens analysed in promoting improvements in metabolic parameters in healthy rats.