Chrononutrition practices and weight loss Original paper

In this observational study, consuming a higher proportion of total daily energy and protein intake earlier in the day was associated with greater weight loss.

The association between changes in chrononutrition practices (e.g., meal timing, temporal eating pattern, and macronutrient intake) and weight loss.

91 participants (average age of 40; 75% women, 25% men) with overweight or obesity who were living in Malaysia.

This study was a secondary analysis of a 12-week chrononutrition–based integrative weight loss program,^[1] which encouraged being physically active and included individualized meal plans, weekly group exercise sessions, behavioral therapy, sleep recommendations, and weekly education sessions.

The meal plans were tailored to whether the individual had a morning or evening chronotype (circadian rhythm, or sleep pattern) and consisted of instructions for daily energy (calorie) intake, macronutrient distribution, temporal pattern of energy intake (the distribution of calorie intake over the course of a day), and meal times.

For example, the participants with a morning chronotype were instructed to consume 75% of their calories in the early window of the day (i.e., breakfast, morning snack, and lunch), whereas the participants with an evening chronotype were instructed to consume only 60% of their calories in the early window of the day (meaning that they consumed more calories later in the day).

Dietary intake and chrononutrition practices were assessed using a 7-day diet history questionnaire.

Compared with the participants who did not achieve notable weight loss (45% of the population), the participants who lost at least 3% of their initial body weight had a greater reduction in total energy, carbohydrate, and fat intake.

In terms of chrononutrition practices, the participants who lost a significant amount of weight consumed more protein in the early window (+3.2%), ate less fat during the late window (−2.6%), and had a shorter daily eating window (−48 minutes). Additionally, their last meal of the day was consumed 39 minutes earlier than baseline, whereas the participants who did not lose significant weight delayed their last meal by 11 minutes. Similarly, the midpoint of eating was 23 minutes earlier than baseline in the participants who lost weight, compared with a delay of 4 minutes in the participants who did not achieve notable weight loss.

Regression models indicated that an increase during the early window of 1% in energy intake overall and energy intake from protein was associated with 9% and 32% greater odds of losing a significant amount of weight, respectively.

A limitation of this study is that meal timing was based on the average mealtime reported by the participants, so it did not consider potential day-to-day variation.