Meal Timing and Macronutrient Composition Modulate Human Metabolism and Reward-Related Drive to Eat

Abstract

The ‘time-of-day’ modifies the metabolic response to meals, but less data exist on the diurnal variations in the hedonic drive to eat. In the present paper, we evaluate the effects of meal timing and macronutrient composition on metabolic responses and the homeostatic vs. hedonic regulation of appetite. In study 1, 84 young, healthy adults completed an online computer-based task assessing the homeostatic and hedonic drive to eat in the morning and evening. In study 2, 24 healthy, young men received 2 identical (850 kcal each) meals in the morning (8:45 h) and evening (18:00 h), of 2 experimental conditions: (i) regular carbohydrate (CH) meals (regular-CH), and (ii) high carbohydrate (high-CH) meals, containing 50 and 80% of energy from CHs, respectively. Serial blood samples were obtained, and the postprandial feelings of hunger, satiety, wanting and liking were assessed. Study 1 revealed a higher hedonic drive to eat in the evening compared to the morning. Study 2 confirmed this diurnal pattern of hedonic appetite regulation and, moreover, showed increased glucose and insulin responses to the evening meal. Postprandial ghrelin and leptin as well as feelings of hunger and satiety were not different between the mealtimes nor between the macronutrient conditions. In line with this, the homeostatic drive to eat was neither affected by the mealtime nor macronutrient composition. Increased the hedonic drive to eat in the evening may represent a vulnerability to palatable food and, thus, energy overconsumption. Together with lower evening glucose tolerance, these findings reflect an adverse metabolic constellation at the end of the day, especially after the ingestion of CH-rich foods.

Snack timing affects tissue clock and metabolic responses in male mice

“…Chocolate consumption was always higher than chow consumption and chocolate/daytime mice consumed more than the respective nighttime cohort (Figure 1). These results go in line with data showing that overconsumption of chocolate peak in the early inactive phase in mice and time-of-day differences in the drive to eat in humans (7,8). Likewise, we found a snack type dependent upregulation of core body temperature and locomotor activity mostly restricted to daytime (Figure 2).…”

“…If food intake is restricted to the normal rest (i.e., light) phase energy expenditure is reduced and mice gain weight compared to animals with ad libitum food access ( 6 ). In contrast, appetite for highly palatable foods peak in the early inactive phase in mice, and also in humans, the drive to snack is higher toward the end of the active phase (i.e., in the evening) ( 7 , 8 ). Sweet craving increases throughout the day in humans ( 9 ) and snacking rather than consuming one hot meal is common in night-shift workers ( 10 ).…”

The circadian neurobiology of reward

“…In mice, drug‐induced place preference and sensitization are highest in the early inactive phase 51 . In line with this, hedonic appetite rhythms peak in the late active/early inactive phase in both humans and mice 52,53 . Hence, both food and drug reward rhythms suggest an influence of the circadian clock on the reward system.…”

“…51 In line with this, hedonic appetite rhythms peak in the late active/early inactive phase in both humans and mice. 52,53 Hence, both food and drug reward rhythms suggest an influence of the circadian clock on the reward system. It is still under investigation whether in humans reward signaling pathways themselves exhibit circadian rhythms.…”

When should I eat: A circadian view on food intake and metabolic regulation

“…13 More recently, we also reported a time-of-day effect regarding food reward in normal-weight adults, who reported increased wanting for high-caloric foods in the afternoon and evening hours. 67 The role of circadian rhythms has also been shown regarding both the homeostatic and hedonic components of appetite control, even though it has been less emphasized. 12 The temporal context of eating and remarkable diurnal rhythms in hormone profiles and the metabolic response to food intake demonstrate the role of the circadian system in regulating the homeostatic control of food intake.…”