Skipping breakfast and 5‐year changes in body mass index and waist circumference in Japanese men and women

OBJECTIVE: This study investigated the relationship between frequency of skipping breakfast and annual changes in body mass index (BMI) and waist circumference (WC). METHODS: The participants were 4,430 factory employees. BMI and WC were measured repeatedly at annual medical examinations over a 5‐year period. The association between frequency of skipping breakfast at the baseline examination and annual changes in anthropometric indices was evaluated using the generalized estimating equation method. RESULTS: The mean (standard deviation) BMI was 23.3 (3.0) kg m(−2) for men and 21.9 (3.6) kg m(−2) for women; and the mean WC was 82.6 (8.7) cm for men and 77.8 (9.8) cm for women. During the follow‐up period, mean BMI increased by 0.2 kg m(−2) for men and women, and mean WC increased by 1.1 cm for men and 1.0 cm for women. The annual change in the BMI of men who skipped breakfast four to six times per week was 0.061 kg m(−2) higher, and that of those who skipped breakfast seven times per week was 0.046 kg m(−2) higher, compared with those who did not skip breakfast. Annual changes in the WC of male participants who skipped breakfast seven times per week was 0.248 cm higher than that of those who did not skip breakfast. Skipping breakfast was not associated with changes in BMI or WC in women. CONCLUSIONS: Skipping breakfast was closely associated with annual changes in BMI and WC among men, and eating breakfast more than four times per week may prevent the excessive body weight gain associated with skipping breakfast.