Is eating earlier in the day healthier than later?

Relation

Mazri FH, Manaf ZA, Shahar S, et al. Do temporal eating habits differ between healthy and unhealthy overweight/obese individuals?Nutrients.2021;13(11):4121.

Key to take away

Higher energy intake earlier in the day and lower energy intake later in the day are metabolically more beneficial and reduce the risk of transitioning into a metabolically unhealthy state.

Draft

Cross-sectional, single-clinic, observational study

Participant

This study recruited 299 volunteers (73.6% women) in the Klang Valley region of Malaysia. All participants were government employees who did not work rotating shifts (to control for circadian disruption as a confounder). Otherwise, the inclusion criterion was a body mass index (BMI) of 25.0 kg/m²or older (overweight/obese) and age between 20 and 59 years (age: 40.3 ± 6.9 years).

After researchers applied the study criteria, the 299 participants were divided into 126 (42%) participants with metabolically unhealthy obesity (MUO) and 173 (58%) participants with metabolically healthy obesity (MHO).

Participants were excluded if they were pregnant or breastfeeding, had undergone bariatric surgery, or had a diagnosis of a chronic disease, including liver, heart, kidney disease, or cancer.

intervention

Trained dietitians and nutritionists administered a 7-day retrospective Dietary History Questionnaire (DHQ).

The investigators analyzed the food measurements using Nutritionist Pro^TMSoftware.

They averaged the times of participants' meals and calculated midpoints to arrive at temporal patterns of energy and macronutrient intake. They classified these temporal patterns into early and late eating windows.

Meals eaten before halftime were considered early eating windows and meals after halftime were considered late eating windows.

Study parameters assessed

The investigators conducted the study for 6 months (August 2019–January 2020).

The early versus late eating window was defined by determining the midpoint between the first and last meal for each subject and then calculating whether the majority of calories were eaten before (early eating window) or after (late eating window) midpoint.

Laboratory values ​​included fasting blood glucose and insulin levels. HbA_1cTotal cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, non-HDL cholesterol, triglycerides and uric acid levels.

Investigators also measured waist circumference, height and weight, and blood pressure for metabolic health status parameters. To calculate body composition, they used a bioelectrical impedance analyzer (BIA).

Participants were classified as metabolically unhealthy obese (MUO) if they met 3 or more of the 5 following criteria:

• Nüchternblutzucker (FBG) über 5,6 mmol/l oder medikamentöse Behandlung zur Kontrolle des Blutzuckers
• Nüchtern-Triglyceride (TG) über 1,7 mmol/l oder medikamentöse Behandlung zur Kontrolle der Lipide
• Fasten HDL-C weniger als 1,29 mmol/l für Frauen; Nüchtern HDL-C weniger als 1,03 mmol/L für Männer
• Systolischer Blutdruck über 130 mmHg und diastolischer Blutdruck über mmHg oder medikamentöse Behandlung zur Kontrolle des Bluthochdrucks
• Taillenumfang (WC) größer als 80 cm bei Frauen; Taillenumfang größer als 90 cm bei Männern

Metabolically healthy obese (MHO) participants were those who met 2 or fewer of the above parameters.

Investigators administered a Night Eating Questionnaire (NEQ) to screen for the presence of night eating syndrome; They used 13 of the 17 items in this study, questions 1 to 12 and question 14. Scores ranged from 0 to 52, with scores above 25 indicating night eating syndrome.

In the Klang Valley region of Malaysia, 20% of the population has a split sleep schedule due to morning prayers. Investigators used the Munich Chronotype Questionnaire (MCTQ) to adjust for participants who had a split sleep schedule; This takes the focus of sleep to correct sleep debt and create morning or evening chronotypes.

The investigators administered the Global Physical Activity Questionnaire (Malaysian version) to assess participants' physical activity.

Primary outcome

The study was designed to assess whether time of day of energy and macronutrient intake is associated with metabolically healthy or unhealthy adiposity in overweight/obese individuals, as designated by ana prioriCriteria.

Key insights

There were no significant differences between the MHO and MUO participants in sleep characteristics, physical activity, lifestyle characteristics, or nighttime eating.

Both MHO and MUO participants were similar in mean age. There was no significant inherent difference in morning and evening chronotypes between the two groups.

When investigators adjusted for all lifestyle parameters such as sleep, physical activities, and lifestyle, they found that MHO participants expended more than 60% of their energy during the early window. MUO participants expended less than 60% of energy intake during the early window. Instead, MUO participants used more than 40% of their energy during the late window.

MUO participants used a lower proportion of energy during the early window: 59.0% (P=0.008); Carbohydrates: 30.6%, (P=0.021); Protein: 9.7% (P=0.049).

MUO participants consumed a higher proportion of energy during the late window: 41% (P=0.008); Carbohydrates, 18.1% (P=0.019); Fat 13.1% (P=0.024).

Additional results found that the MUO group had significantly more male participants at 53% compared to 46.8% male participants in the MHO group (P=0.021).

The MUO participants had higher adiposity and both systolic and diastolic blood pressure higher than MHO. The biochemical parameters of the MUO participants were worse than those of the MHO participants, except for total cholesterol, LDL cholesterol and uric acid levels.

This research suggests that higher energy intake earlier in the day and lower energy intake later in the day are metabolically beneficial. This has been shown to be beneficial for morning and evening chronotypes. An additional prospective study needs to be conducted to understand whether chrono-nutrition can metabolically delay the progression from metabolically healthy obesity to metabolically unhealthy obesity.

transparency

The research for this study was funded by the Ministry of Higher Education. The authors did not provide any information.

Practice implications

This study suggests that consuming more calories earlier in the day and reducing those calories later in the evening may be metabolically more beneficial than eating later.

The parameters of metabolic health status that have been used to define “metabolically unhealthy” are also those that determine the presence of metabolic syndrome.¹Metabolic syndrome increases the risk of chronic diseases: heart disease, diabetes and stroke.

This has strong implications for eating when it comes to teaching people about healthy eating habits in terms of the best times to eat meals and meal composition.

This study may prove particularly helpful in explaining the effects of eating during the day rather than skipping meals and eating larger meals in the evening. The increased risk of metabolic syndrome symptoms and obesity with consuming higher amounts of energy later in the evening was also found in a small study by Gu C et al.²

With the increasing popularity of intermittent fasting, many people have turned to shifting their meals to later in the day with the goal of losing weight and achieving a healthier metabolic state.

While intermittent fasting, when used correctly, can be a very successful approach to reducing the parameters of metabolic syndrome, this current study suggests that consuming energy-dense meals later in the day is correlated with metabolic syndrome, increasing the risk of more serious chronic diseases.

When teaching or speaking to patients about intermittent fasting, it is best to share information about time windows and calorie intake measurements and emphasize that patients should aim for the early energy intake window and reduce high energy intake later in the day. It is also helpful to perform labs and repeat labs to ensure that metabolic parameters are improving with nutritional guidance.³

There is another interesting aspect of this study. Despite the fact that the overall population of this study was female (73.6%), there were significantly more males in the MUO group than in the MHO group. As we continue to educate people about healthy eating habits, perhaps a special focus needs to be placed on educating men about temporary eating habits to reduce their risk of metabolic syndrome and chronic diseases related to eating habits.

(link removed)