Alexey Moskalev, a corresponding member of the Russian Academy of Sciences, explains that milk breaks the “clean period,” or fasting window, during which a person consumes no food, while tea does not.
اضافة اعلان
According to Moskalev, the fasting window is the period between meals and is considered one of the strictest forms of daily fasting, allowing only water. These intervals are necessary to give the body regular breaks from calorie intake, as metabolism is not designed to process food continuously from early morning until late at night. Doing so may lead to health problems.
He notes that when nutrient intake is restricted, metabolism shifts into a repair state. Clinical trials have shown that avoiding food during an eight-to-10-hour period of the day improves metabolic markers. Along with sleep and physical activity, this practice is among the factors supported by some of the strongest scientific evidence for reducing the risk of premature death.
“A spoonful of sugar, milk, cream, juice or any sweetened drink provides nutrients and officially marks the end of the fasting window,” he says. “However, I do not recommend turning this into a mathematical game over a single drop of milk. For health, maintaining a regular fasting period that is long enough is more important than pursuing complete metabolic ‘purity’ down to the last calorie.”
Another area of uncertainty concerns calorie-free food additives and sweeteners. Very little information is available about their effects on metabolism, making it difficult to determine whether they are acceptable during fasting.
He warns: “Regular use of almost all sweeteners has been shown to have adverse health effects.”
Regarding the eating window itself, Moskalev says the popular rule of “not eating after 6 p.m.” has no scientific basis. What matters is not the time on the clock, but the body’s circadian rhythm, the duration of the eating window and its timing in relation to sleep. For example, eating between 10 a.m. and 8 p.m. creates a 10-hour eating window that can fit a variety of schedules.
However, available evidence generally suggests that eating earlier is physiologically preferable because insulin sensitivity and other metabolic processes follow the body’s circadian rhythm. Nevertheless, the rule that the last meal must be eaten exactly three hours before bedtime cannot be applied universally, as science has not established such a precise threshold. If someone goes to sleep between 11 p.m. and midnight, having dinner at 8 p.m. appears reasonable.
“I recommend prioritizing a consistent daily routine, avoiding continuous late-night snacking, keeping the eating window within a reasonable duration and, if possible, avoiding the main meal in the evening,” he says.
Source: Al-Ghad.
