Beneficial Effects of Early Time-Restricted Feeding on Metabolic Diseases: Importance of Aligning Food Habits with the Circadian Clock

Abstract

The importance of metabolic health is a major societal concern due to the increasing prevalence of metabolic diseases such as obesity, diabetes, and various cardiovascular diseases. The circadian clock is clearly implicated in the development of these metabolic diseases. Indeed, it regulates physiological processes by hormone modulation, thus helping the body to perform them at the ideal time of day. Since the industrial revolution, the actions and rhythms of everyday life have been modified and are characterized by changes in sleep pattern, work schedules, and eating habits. These modifications have in turn lead to night shift, social jetlag, late-night eating, and meal skipping, a group of customs that causes circadian rhythm disruption and leads to an increase in metabolic risks. Intermittent fasting, especially the time-restricted eating, proposes a solution: restraining the feeding window from 6 to 10 h per day to match it with the circadian clock. This approach seems to improve metabolic health markers and could be a therapeutic solution to fight against metabolic diseases. This review summarizes the importance of matching life habits with circadian rhythms for metabolic health and assesses the advantages and limits of the application of time-restricted fasting with the objective of treating and preventing metabolic diseases.

Association between Irregular Meal Timing and the Mental Health of Japanese Workers

“…Although there have been many studies discussing the timing of food intake, the irregularity of mealtimes was not the main focus of these studies [ 33 ]. For instance, breakfast skipping and nighttime snacking have been found to be associated with evening chronotype with greater social jet lag, which has also been associated with obesity or lifestyle-related diseases [ 11 , 12 , 13 , 20 ]. Breakfast skipping has also been confirmed to be associated with a higher incidence of obesity and hyperlipidemia [ 34 ].…”

“…In addition to specific food groups, eating behavior is also an important factor in this regard. Breakfast skipping has been associated with higher levels of stress, depression, and fatigue [ 11 , 12 ]. Patients with night eating syndrome (NES) show nocturnal emotional eating with a higher depressed mood in the evening and lower sleep quality [ 13 , 14 ].…”

Early or Delayed Onset of Food Intake in Time-Restricted Eating: Associations with Markers of Obesity in a Secondary Analysis of Two Pilot Studies

“…There is increasing evidence that the timing of food intake influences the development of overweight, obesity, and metabolic disorders [ 35 , 36 ]. Hence, based on the evolutionary circadian rhythm of metabolism, early TRE is investigated on its presumed better effects on metabolic markers [ 14 ], and evidence is accumulating for the superiority of an earlier versus a later time window of food intake in TRE [ 15 ]. Currently, there are mainly smaller studies, often of a pilot character, that address this hypothesis, and against this background, most of the results presented below should therefore be viewed critically.…”

“…Currently, there are mainly smaller studies, often of a pilot character, that address this hypothesis, and against this background, most of the results presented below should therefore be viewed critically. Several studies of early TRE with stopping food intake before 19:00 h resulted in better weight loss, while late eating showed reduced beneficial effects [ 14 ]. A crossover study with 11 participants showed that eating three meals between 08:00 and 14:00 resulted in improved glucose response and detection of markers of circadian rhythmicity and autophagy as compared to a control schedule from 08:00 to 20:00 [ 37 ].…”

“…Participants showed moderate weight loss and reductions in weight circumference and reported improved health-related quality of life (HRQoL) and sleep quality [ 11 , 12 , 13 ]. Emerging research focuses on the timing of TRE and suggests advantages of earlier onset of timeframes of food intake [ 14 ], and the different timing of the eating window seems to be an important factor with regard to the outcome [ 15 ]. Several physiological features suggest that an earlier start of food intake may be useful: food-induced thermogenesis is twice as high after meals in the morning as in the evening [ 16 ], the glucose tolerance of the body decreases continuously throughout the day after a high in the morning [ 17 ], and late-night eating leads to metabolic disturbances [ 18 ] and disruption of the circadian rhythm [ 17 ].…”