"Cell" sub-issue: Eat more breakfast, lose weight easier! Scientists have found that eating more in the morning or evening has similar weight loss effects, but eating breakfast is beneficial to reduce hunger

*For medical professionals only

Many people may have been taught by the elders that "eat well for breakfast, eat full at noon, and eat less at night", I don't know when to be, the friends around to lose weight are also very careful to eat less at night
.
Studies have shown that even with the same intake, different intake times affect energy utilization, leading to different weight loss effects, but the underlying mechanisms of different calorie utilization remain uncertain [1-4].

Compared with "opening your legs", "controlling your mouth" can be said to be much easier, and I believe that many friends are also very concerned
about the impact of eating time and food intake allocation on weight loss results.
Alexandra M.
Johnstone's team at the University of Aberdeen in the United Kingdom explored the effects of daily caloric allocation on energy balance, metabolism, and appetite through a randomized crossover trial [5].

They found that during the consumption of weight loss meals, whether it was a larger proportion of calories in breakfast or a larger proportion of calories in dinner, the weight loss effect was similar, and there was no difference
in energy metabolism.
Eating more calories in the morning reduces appetite and hunger, and corresponding behavioral changes (reduced intake) may help dieters achieve better weight loss under liberal eating conditions
.

The study was recently published in
Cell Metabolism.

Article cover

In this study, Alexandra M.
Johnstone'steam designed a diet meal with 30%, 35%, and 35% of protein, carb, and fat
, respectively.
In the case of the same nutrient composition, compare the impact of different calorie intake proportions at different meal times on the effect of weight loss meals:

HEARTY BREAKFAST (ML): THE TOTAL CALORIES ARE 1736 kcal/DAY, WITH BREAKFAST, LUNCH AND DINNER ACCOUNTING FOR 45%, 35% AND 20% OF THE CALORIES RESPECTIVELY
.

Hearty Dinner (EL): The total calories are 1749 kcal/day, with breakfast, lunch and dinner accounting for 20%, 35% and 45%
respectively.

A total of 30 participants completed the study, 16 male and 14 female, with an average age of 50.
9 years, an average weight of 95.
4 kg, and an average body mass index (BMI) of 32.
5
.
Of these, 14 were first randomized to the ML diet and 16 to the EL diet
first.
All food and water were provided by the researchers, and eating times
were strictly controlled.
Participants reported all the foods they consumed outside of their prescribed diets and all leftovers were weighed
.

Before the trial began, all people received a week-long baseline diet to maintain energy balance, with 33%
caloric intake in the morning, lunch and evening.
Participants were then randomly assigned to receive either the ML diet or the EL diet
for four weeks.
In contrast to themselves, both groups were washed off from a one-week baseline diet followed by a four-week diet in opposite patterns
.

Design of experiments

Preliminary analysis showed no significant difference
between the two dietary patterns in total caloric intake and macroelement intake.
The ML diet had significantly more leftovers for breakfast and lunch than on the EL diet, and slightly lower leftovers for dinner than on the EL diet
.
In addition, the breakfast and lunch times of the two groups were basically the same, and the dinner time of the EL diet group was 20 minutes
earlier than that of the ML diet group.

Anthropometric data at the end of each dietary intervention period

Unlike previous findings, the research team found that the allocation of caloric intake did not affect caloric expenditure
.
There was no clear difference
in total daily energy expenditure (TDEE) between the ML and EL diet groups.

At the same time, the two isocalorie diets with the same composition but different energy distribution resulted in significant weight
loss at the end of each dietary intervention period.
The two groups showed almost the same trend of weight loss, and there was no difference in weight loss between the ML diet group and the EL diet group at the end of week 4 (p=0.
848).

Weight loss trends in a 4-week weight loss diet

In this study, the research team also measured and reported all components of total daily energy expenditure, including resting metabolic rate (RMR), food thermal effect (TEF), and results
from the exercise recorder.
Resting metabolic rate was significantly reduced after both ML and EL diets compared with baseline, a result consistent with weight loss, but there was no difference
in resting metabolic rate between groups.

RMR was significantly reduced after ML and EL diets, but there was no difference between the two groups

The research team further investigated the effects
of ML and EL diets on glucose, insulin, and blood lipids.

After two calorie-restricted diets, participants had significant reductions in blood glucose and fasting insulin, and this reduction was not significantly different
in the ML and EL diet groups.
In addition, there were significant reductions in total cholesterol, LDL, and triglycerides on both ML and EL diets compared with baseline, but there were no significant differences
between the two groups.
Therefore, there was no clear difference
between the effects of ML and EL diets on glucose, insulin, and lipids.

Metabolic health parameter measurements at the end of each dietary intervention period

Seeing this, those friends who are too lazy to eat breakfast must be clapping their hands (such as the singularity cake at the moment).

However, the next conclusion will poke at the pain point of many people - do you always feel lonely in your mouth? Or is it "uncontrollable" as soon as dinner arrives during weight loss? Harm, that's probably because you don't eat breakfast!

That's right, the team also explored changes in subjective factors such as participants' food cravings in different eating patterns
.

They used visual analogue scales (VASs) to assess changes in participants' subjective
appetites.
The results showed that the ML diet had significantly lower daily hunger, desire to eat, expected consumption, thirst, and overall appetite scores compared
to the EL diet.
Under liberal diet conditions, the ML diet may suppress appetite to a greater extent and reduce calorie intake for lunch and dinner, thereby contributing to the weight loss effect
of the ML diet.

Compared to the EL diet, the ML diet had significantly lower hunger and appetite

Previous studies have shown significant diurnal changes
in the secretion of many appetite-related hormones on fasting and after meals.
For example, postprandial somatotropin is more inhibited
after breakfast than eating the same food at night.
However, how daily energy allocation affects appetite-related hormones throughout the day is unclear
.

This study showed no difference
between ML and EL diets in fasting PYY, ghrethyrin, enterogastrin-suppressing peptide (GIP), and glucagon-like peptide-1 (GLP-1) secretion.
However, compared with the EL diet, the gastric auxin response 2 hours after breakfast on the ML diet was significantly lower, PYY, GIP and GLP-1 were significantly increased, and the gastric emptying time was significantly prolonged
.
Therefore, eating a little more in the morning can help increase the amount of food left in the gut and emptying time, reducing the likelihood of
overeating later in life.

A hearty breakfast in the ML diet group resulted in greater changes in appetite-related hormones and slower gastric emptying

This is the first randomised crossover trial
comparing ML and EL diets.
The findings overturn earlier research suggesting that the ML diet may contribute to weight loss
by affecting calorie intake through changes in appetite.

Overall, eating more in the morning or eating more in the evening had a similar weight loss effect under controlling total intake, and there was no difference
in energy metabolism.
But eating more in the morning can help reduce appetite and hunger, and the resulting reduction in intake can help dieters achieve better weight loss
.

References:

[1] Garaulet M, Gómez-Abellán P.
Timing of food intake and obesity: a novel association.
Physiol Behav.
2014; 134:44-50.
doi:10.
1016/j.
physbeh.
2014.
01.
001

[2] Jakubowicz D, Barnea M, Wainstein J, Froy O.
High caloric intake at breakfast vs.
dinner differentially influences weight loss of overweight and obese women.
Obesity (Silver Spring).
2013; 21(12):2504-2512.
doi:10.
1002/oby.
20460

[3] Arble DM, Bass J, Laposky AD, Vitaterna MH, Turek FW.
Circadian timing of food intake contributes to weight gain.
Obesity (Silver Spring).
2009; 17(11):2100-2102.
doi:10.
1038/oby.
2009.
264

[4] Fonken LK, Workman JL, Walton JC, et al.
Light at night increases body mass by shifting the time of food intake.
Proc Natl Acad Sci U S A.
2010; 107(43):18664-18669.
doi:10.
1073/pnas.
1008734107

[5] Ruddick-Collins LC, Morgan PJ, Fyfe CL, et al.
Timing of daily calorie loading affects appetite and hunger responses without changes in energy metabolism in healthy subjects with obesity [published online ahead of print, 2022 Aug 30].
Cell Metab.
2022; S1550-4131(22)00344-8.
doi:10.
1016/j.
cmet.
2022.
08.
001

Responsible editorEddy Zhang