The Surprising Reason Eating In The Evening Makes You Gain Weight

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When you grab a bite to eat, the time on the clock could be just as crucial as what’s on your plate. Your body’s capability to process and use calories changes throughout the day due to your natural circadian rhythm.

Studies suggest that calories consumed in the morning can be metabolized differently than those eaten in the evening, potentially leading to differences in weight management and overall health. Let’s learn more about this!

The Magic Of The Natural Circadian Rhythm.

All of this has to do with your natural circadian rhythm, but what exactly is that?

The natural circadian rhythm, often referred to as the “body clock,” is an internal mechanism that regulates the sleep-wake cycle and other physiological processes over approximately a 24-hour period. This rhythm is influenced by environmental cues, especially light and darkness, which affect the secretion of hormones like melatonin, involved in sleep regulation, and cortisol, which helps manage energy levels and alertness.

The typical circadian rhythm aligns with the day-night cycle. During the day, exposure to light prompts the brain to signal other parts of the brain that control hormones, body temperature, and other functions (including metabolism) to keep us awake, functioning and alert. When darkness falls, the brain responds by initiating the production of melatonin, which promotes sleepiness.

Most adults experience the strongest sleep drive between 2:00-4:00 am and in the afternoon between 1:00-3:00 pm, although there is variation depending on whether someone is a “morning person” or an “evening person.”. These times can vary based on individual differences in circadian rhythms.

Circadian rhythms also influence eating habits, digestion, body temperature, and other bodily functions. Disruptions to the natural circadian rhythm, such as those caused by shift work, jet lag, or irregular sleep patterns, can have negative effects on sleep, mood, metabolism, and overall health. Maintaining a regular schedule that aligns with natural light and dark cycles can help keep the circadian rhythm stable and promote better health, metabolism, and well-being.

Impact of Morning Calories on Metabolism

All of this is to say that when you eat your calories is just as crucial as what you eat. Recent studies suggest that your body handles morning calories differently than those consumed at night (because of your natural rhythm), possibly leading to better weight management when you front-load your day with more calories.

Boosting Metabolic Rate

That’s because consuming calories in the morning can elevate your metabolic rate. This means your body tends to burn more calories processing breakfast than it does digesting an evening meal. Specifically, you’ll burn about 50% more calories if the same meal is eaten in the morning instead of the evening, a phenomenon influenced by your body’s circadian rhythm.

A group of Italian researchers randomized 20 people to eat the same standardized meal at either 8:00 am or 8:00 pm and had them return a week later to do the opposite (source).

So, each person had a chance to eat the same meal for breakfast and dinner. After every meal, the study participants were placed in a “calorimeter” contraption to precisely measure how many calories they were burning over the next three hours.

The researchers calculated that the meal given in the morning took about 300 calories to digest, whereas the same meal given at night only used up about 200 calories to process. The meal was about 1,200 calories, but, when eaten in the morning, it ended up only providing about 900 calories compared to more like 1,000 calories at night.

Same meal, same food, same amount of food, but effectively 100 fewer calories when consumed in the morning rather than at night. So, a calorie is not just a calorie. It depends on when we eat it. 

Source

Feeling Fuller

Eating more of your calories during the morning hours could also lead to greater satiety. This implies you’re likely to feel fuller after a morning meal compared to an equivalent evening meal. Feeling fuller can reduce the urge to snack, hence, promoting a negative calorie balance, which is essential for weight loss.

In a study where 37 overweight women with a BMI of 27 – 42 participated in a diet plan, those who concentrated their calorie intake in the morning experienced greater appetite suppression (source). They ate 45% of their calories in the morning, 35% at noon, and 20% in the evening.

The other group, which mainly ate their calories in the evening, divided their calories like this: 20% morning, 35% noon, and 45% evening. As said, this resulted in a higher appetite and less weight loss than the morning group.

Stefan K.

Stefan has been vegan since 2019 and has been regularly working on his strength since the beginning of 2023. He’s on a mission to help other vegans get stronger and have all of them achieve the quality of life they deserve.