Assessment of the Effects of Acute Exposure to Cold and Heat on Appetite

Military personnel and athletes have a very high energy expenditure, which is increased during certain key periods (intense training, competition and missions). Compensating for this expenditure through adequate energy intake can be complicated by physiological ingestive limits and logistical and organizational constraints (number of meals, food availability), leading these populations to regularly find themselves in an energy deficit situation (intake below requirements). If this situation persists, it could impair physical and cognitive performance, as well as major physiological functions. Among the many constraints to which military personnel and athletes are subjected (stress, sleep deprivation, travel, etc.) that can increase the risk of energy deficiency, the impact of thermal environmental constraints is very imperfectly known. Seasonal impact and travel to countries with very different thermal environments from temperate countries can lead these populations to work in cold and hot conditions for long periods. Understanding how exposure to hot and cold alters appetite and energy intake is therefore of the high importance. Our previous "TEMPCA" study highlighted a modulation of preferences for warm or cold foods depending on the exposure environment. By being able to adapt their food intake to these preferences, subjects were able to maintain a decent energy intake. The primary objective of this study is to determine the effect of the temperature of the food served (hot or cold) on changes in food intake during acute exposure to hot and cold. We hypothesized that adapting the temperature of the food served according to the exposure environment (hot in a cold environment and cold in a hot environment) would enable adequate levels of energy intake. Secondary objectives are to determine the influence of the environment on the levels of interstitial glucose during the preprandial period and to investigate the impact of thermal exposure (modulation of core temp