Acute Effects Of Carrying On A Hot Vest And A Footbath On Energy Intake

To prevent overweight and obesity, reducing energy intake (EI) is a theoretical way. Although cooling body temperatures by wearing a cooling vest could increase EI, it is unclear whether EI will be regulated by increasing body temperatures with applicable heating strategy. In addition, lack of evidence about body temperatures and EI in females. PURPOSE: To examine acute effects of carrying on a hot vest and a footbath on EI. METHODS: Eight females and seven males (aged 24 ± 2 and aged 24 ± 2, mean ± SD, respectively) performed two cross-over trials randomly, separated by 28 days. For females, the two trials were conducted on early follicular phase. In hot trial (HT), participants sat from 0930 h to 1030 h and then wore a hot vest (~45 °C) and took a footbath (~43 °C) for one hour until 1130 h. In control trial (CT), participants sat for two hours (0930 h-1130 h). In all trials, from 1140 h, participants consumed a buffet meal until satisfied before 1240 h. EI was calculated from the buffet meal including hot/cold dishes and drinks, fruits and snacks. Tympanic and skin temperatures were assessed. RESULTS: EI was suppressed in HT (886 ± 290 kcal) than CT (1053 ± 335 kcal), and hot food and hot drink consumptions were lower in HT than CT among all participants (all P < 0.05). However, EI was decreased in HT than CT in males (1004 ± 281 kcal and 1251 ± 375 kcal, P = 0.035) but was similar in females (783 ± 272 kcal and 880 ± 172 kcal, P = 0.437). Mean values of tympanic temperatures (Male: 36.4 ± 0.4 °C and 36.0 ± 0.4 °C; Female: 36.7 ± 0.4 °C and 36.4 ± 0.4 °C) and skin temperatures (Male: 34.9 ± 0.7 °C and 33.1 ± 0.4 °C, Female: 34.9 ± 0.4 °C and 33.0 ± 0.5 °C) was higher in HT than CT during 1030 h-1130 h in both males and females (all P < 0.05). In multivariate analysis, lower EI was linked to higher tympanic temperature (β = -5.792, P = 0.014). CONCLUSIONS: This study found that carrying on a hot vest and a footbath suppressed EI, which may result from the decreased hot food and hot drink consumptions, linked with the increased body temperatures. Moreover, EI was decreased only in males but not females. Therefore, this study suggested sex difference existed in EI responding to this acute hot exposure. These findings suggested that hot vest and footbath can be used to suppress EI in young males. Future studies on mechanisms behind sex difference in EI and hot exposure are needed. Supported by: JPMJSP2128