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.

Keywords: cardiovascular disease; circadian clock; intermittent fasting; metabolic diseases; obesity; time-restricted fasting.

Figure 1

Time-of-day-dependent patterns of circulating hormone levels variation. Circadian rhythms are driven by oscillations of endocrine factor levels during the day. These variations are important to perform physiological processes at the optimal time of the day. Melatonin induces the resting phase whereas cortisol prepares the body for the activity phase. The other hormones drive modifications of glucose and lipid metabolism, promoting either catabolism with fatty acid oxidation and glycolysis (FGF21, adiponectin, leptin) or anabolism with lipogenesis and glycogenesis (insulin).

Figure 2

Impacts of food habits on metabolism are connected with the circadian clock. The way that people eat is essential for metabolic health. When food habits (timing and number of meals per day) are misaligned with the circadian clock, they prevent an increased risk of obesity, cardiovascular disorders, and diabetes. On the other hand, practicing time-restricted fasting where the eating window is aligned with circadian rhythms improves metabolic health.