Impact of meal frequency and energy turnover on the regulation of energy intake ; Einfluss von Mahlzeitenfrequenz und Energieumsatz auf die Regulation der Energieaufnahme

Over the last decades, consumption of liquid calories as sugar containing beverages like fruit juices, soft drinks and sweetened coffees increased and became a major risk factor for weight gain. The aim of the first study was to investigate if orange juice consumption together with meals improves energy balance compared to juice consumption in-between meals. The impact of consuming 20% of individual daily energy requirement as orange juice with or in-between three meals per day on weight gain and body composition was therefore investigated in a 2 x 2-week crossover intervention under free-living conditions in 26 healthy adults. Despite the same energy intake in both interventions only the consumption of orange juice in-between meals resulted in a gain in fat mass. This discrepancy seems to be explained by a lack in compensation of energy intake at the following meal when orange juice is consumed in-between meals compared to juice consumption with meals. In conclusion, consumption of liquid calories in-between meals is a risk factor for weight gain and thus snacking should be avoided. In contrast, consumption of sugar containing beverages together with only three meals per day was able to prevent weight gain. Beyond liquid calories, a low energy turnover may also be a risk factor for weight gain. In line with this hypothesis it was proposed that weight control is improved when physical activity and energy intake are both high (high energy turnover) but not with sedentary behavior. In a second study, the acute impact of energy turnover on appetite control was therefore investigated in 16 healthy adults under strictly controlled conditions in a metabolic chamber at different levels of energy balance. Three levels of 24h energy turnover (low PAL 1.31; medium PAL 1.55; high PAL 1.76) were compared in a randomized crossover intervention each under ad libitum energy intake, zero energy balance, caloric restriction (-25%) and overfeeding (+25%). Different levels of energy turnover were achieved by varying durations of ...