To optimize metabolism and regulate appetite (particularly in women), it is advised to avoid skipping breakfast and to prioritize early intermittent fasting—for example, by eating dinner earlier to observe a 12- to 14-hour nocturnal fast—rather than delaying the first meal until midday.

noli's read

The idea of synchronizing food intake with the body's internal clock is supported by rigorous research in chrononutrition. A randomized clinical trial (the ChronoFast study, 2025) indicates that eating earlier in the day improves sleep quality and insulin sensitivity in women compared to late-day eating. From a hormonal perspective, an observational study (Witbracht et al., 2015) confirms that women who skip breakfast exhibit a disruption in cortisol rhythm, with the alertness hormone remaining elevated for a prolonged period. Nevertheless, a recent crossover clinical trial (2025, Science Translational Medicine) adds nuance by showing that if energy intake is strictly equivalent, the actual metabolic differences between eating early or late tend to diminish. Finally, asserting that a simple 12- to 14-hour fast allows one to fully benefit from autophagy is an exaggeration. Research on cellular cleaning suggests that while this process may initiate after 12 hours, it generally requires a much more prolonged fast, on the order of 18 to 24 hours, to be activated significantly in humans.

the sources

1. 1Cioffi I, Evangelista A, Ponzo V, et al. 2018
2. 2Lowe DA, Wu N, Rohdin-Bibby L, et al. 2020
3. 3Liu D, Huang Y, Huang C, et al. 2022
4. 4Jamshed H, Steger FL, Bryan DR, et al. 2022
5. 5Sievert K et al. 2019