It’s long been popular advice among people looking to lose weight to avoid late-night snacking.
No wonder there are so many studies showing that late-night eating is associated with weight gain and an increased risk of obesity.
However, until now, few studies have investigated exactly why late-night eating is associated with weight gain.
This is what a recent United States (US) study seeks to reveal. They found that eating four hours later than normal actually altered many of the physiological and molecular mechanisms that drive weight gain.
This study adds to other recently published studies that found eating earlier in the day was more beneficial for both appetite and weight management.
late meal
To conduct the study, researchers had 16 participants follow two different meal schedules for a total of six days each.
In the first protocol, participants ate early in the day and had their last meal approximately 6 hours and 40 minutes before bedtime.
In the second protocol, participants ate their entire daily meal approximately 4 hours later.
This meant they skipped breakfast and instead had lunch, dinner, and dinner. Their last meal was consumed just two and a half hours before bedtime.
The study was conducted in a controlled lab so that participants in each group received the same diet and all meals were evenly spaced approximately four hours apart.
To understand how slow eating affects the body, researchers looked at three different measures specifically related to weight gain.
- Appetite effect,
- Effect of meal time on energy expenditure (calories burned), and
- Molecular change from adipose tissue.
Appetite was measured using two techniques. The first method was to have the participant rate her hunger throughout her day.
The second technique was to take blood samples to check the levels of appetite-regulating hormones in the participants’ blood. Examples include leptin (which makes you feel full) and ghrelin (which makes you feel hungry).
These hormones were assessed hourly for 24 hours on days 3 and 6 of each trial.
A technique called ‘indirect calorimetry’ was used to assess the impact of meal timing on daily energy expenditure. It measures both the amount of oxygen a person uses and the amount of carbon dioxide they produce.
This helps researchers estimate how many calories a person’s body burns throughout a typical day.
To find out how late-night eating affects how the body stores fat at the molecular level, researchers performed biopsies of adipose tissue taken from the abdomen. Agreed.
The team found that compared to early eating patterns, late eating not only increased subjective hunger the next day, but also increased the ratio of ‘hunger’ hormones in the blood. Participants ate the same diet for both protocols.
Eating later also burned fewer calories the next day.
In participants with adipose tissue biopsies, it was also shown that slow eating causes molecular changes that promote fat accumulation.
Taken together, these results indicate that slow eating can lead to many physiological and molecular changes that can lead to weight gain over time.
potential for weight gain
While we don’t fully understand all the mechanisms underlying why late-night eating drives weight gain, this study suggests that it’s probably the result of many factors working together. .
One theory why eating late makes you gain weight may be due to your circadian rhythm.
The human body has a natural circadian rhythm, which is controlled by the brain and influences the normal rise and fall of hormones. It is particularly responsive to sunlight and food intake.
Meal times are intrinsically related to human circadian rhythms. We usually sleep when it gets dark outside and eat during the day.
Eating late can disrupt your natural circadian rhythm, disrupting your body’s hunger signals, burning calories and storing fat.
However, this link has so far only been shown in studies on animals.
Given that the new study was only conducted on a limited number of participants and was conducted over a very short time frame, we wonder whether these changes are only temporary, and whether the long midnight hours Further research is needed to better understand the effects of diet on these. Mechanism of weight gain.
However, other studies have also found that people who tend to eat late at night tend to gain weight more easily.
Other large-scale studies examining the relationship between meal timing disruptions and energy balance (skipping breakfast, eating late at night, shift work, etc.) have found that these eating patterns are associated with weight gain and metabolic disorders (such as ) was associated with an increased risk of hypertension or type 2 diabetes).
This study shows a growing body of evidence showing how important meal timing is when it comes to weight.
Based on what this and other studies have shown, weight-conscious people may prefer to skip late-night snacking and eat most of their meals earlier in the day. conversation
About the author:
Alex Johnstone is the Personal Chair of Nutrition at the Rowett Institute at the University of Aberdeen.
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