Does Late-Night Eating Disrupt Metabolism?

There are many factors that can speed or slow the metabolism. Arguably, nutrition is what dictates how you perform in sports and how healthy you are. As metabolism can make or break a person’s fitness goals, it is imperative to understand what can change it. And today we look at late-night eating and its effect on the body.

There are a couple of reasons why a person would go through a diet. Primarily, most people think a diet is for losing weight. However, you can change your eating habits if you want to gain weight or build muscle and also for health benefits.

Although dieting can range from various extreme examples to the most simple ones, many people struggle with hunger levels before going to bed. Check out what scientific studies discovered about late-night eating and metabolism disruption.

What is Metabolism

Metabolism is the body’s way of converting food into energy and performing essential functions. It involves two processes: catabolism, breaking down food for energy, and anabolism, using energy to build and repair body tissues.

Several factors can influence metabolism, including:

• Body composition: Lean muscle mass requires more energy to maintain than fat tissue, so individuals with a higher muscle mass tend to have a higher metabolic rate.
• Age: Metabolic rate tends to decrease with age due to a loss of muscle mass and hormonal changes.
• Hormonal factors: Hormones such as thyroid hormones, insulin, and cortisol play a role in regulating metabolism.
• Genetics: Some individuals may have a genetically higher or lower metabolic rate.
• Environmental factors: Extreme temperatures and certain medications can affect metabolism.

Metabolism is regulated by various factors, including hormones, enzymes, and the body’s energy needs. It determines how many calories you burn at rest (basal metabolic rate) and is also influenced by physical activity.

Many argue that since metabolism determines how many calories you burn while at rest, it is arguably the most important factor when it comes to losing weight.

Related: How to Speed Up Metabolism for Faster Fat Loss

Does Late-Night Eating Disrupt Metabolism?

Imagine your body as a machine that relies on fuel to function effectively. The fuel, in this case, is the food you consume. If you consistently consume a diet abundant in unhealthy foods like processed items, sugary drinks, and fast food, you’re essentially providing your body with low-quality fuel.

While increasing your exercise levels may help offset some extra calories, it’s challenging to completely burn off the surplus calories and unhealthy substances that come with a poor diet. For instance, a single fast food meal can contain over 1,000 calories, surpassing what an average person can burn in an hour of exercise. Moreover, a diet high in processed and sugary foods can contribute to inflammation, insulin resistance, and other health issues that exercise alone cannot fully address.

If your goal is to build more muscle, you may need to consume more calories than your body requires for maintenance. However, it’s important to understand that this doesn’t grant you the freedom to consume any type of food without consequences. It’s essential to recognize that 1,000 calories from ice cream are not equivalent to 1,000 calories from chicken breast in terms of nutritional value and impact on your body.

Why You Cannot Outrun a Bad Diet

When it comes to nutrition, the focus is often on what we eat, but recently, there has been increasing interest in the timing of meals. Based on an article written by Eric Trexler and published on Stronger by Science analysing two different studies, we will dig deeper into the effects of late-night eating on metabolism.

The first study investigated the impact of shifting meal times later in the day, while the second study compared calorie distributions between morning and evening. By examining the outcomes related to appetite and energy expenditure, we can gain insights into the potential effects of late-night eating on our bodies.

Study 1

The first study involved 16 participants with overweight or obesity who completed two laboratory protocols. The protocols included an early eating intervention and a late eating intervention, with meal times shifted 250 minutes later. Before each protocol, participants had a lead-in period, followed by a six-day stay in the lab. The researchers measured various variables, focusing on appetite and energy expenditure.

Results showed that late-night eating led to a decrease in 24-hour body temperature, which is often used as an indicator of overall metabolism. This finding suggests that late eating may result in a lower metabolic rate. Additionally, waketime energy expenditure, assessed multiple times throughout the day, decreased by approximately 5%. This decrease would correspond to an estimated reduction of 59.4 ± 13.9 kilocalories burned during waking hours. The study also revealed significant changes in appetite-related hormones, leading to increased hunger levels among participants.

Study 2

In the second study, researchers examined the effects of different calorie distributions on weight loss. The study involved 30 participants with overweight or obesity and employed a crossover design. Participants followed two dietary conditions, one with more calories in the morning and the other with more calories in the evening. Isoenergetic diets were provided, aiming to match each individual’s basal metabolic rate. The researchers measured energy expenditure outcomes, including resting metabolic rate and total daily energy expenditure, along with various appetite-related outcomes and changes in body weight over a four-week period.

The results indicated that both morning-loaded (more calories in the morning) and evening-loaded (more calories in the evening) diets led to similar amounts of weight loss after four weeks. There were no significant differences in energy intake, daily energy expenditure, or resting metabolic rate between the two conditions. However, subjective ratings of hunger, desire to eat, prospective consumption, thirst, and appetite scores were higher in the evening-loaded diet condition.

What Does This All Mean?

Comparing the findings from both studies, it is evident that late-night eating can have certain effects on metabolism and appetite. The first study demonstrated a decrease in metabolic rate and an increase in hunger levels associated with late eating. This suggests that consuming meals later in the day might lead to a greater risk of weight gain. However, it is important to note that the study’s duration was limited, and it did not directly measure changes in body mass.

The second study provided a longer-term perspective and showed that the distribution of calories throughout the day did not significantly impact weight loss or energy expenditure. Both morning-loaded and evening-loaded diets led to comparable weight loss outcomes. However, the evening-loaded diet condition resulted in higher subjective ratings of hunger and other appetite-related factors. These findings indicate that the timing of energy intake might influence appetite regulation but has less influence on weight loss when overall energy intake is controlled.

It is crucial to consider the limitations of these studies. Firstly, they focused on different research questions. The first study examined different feeding windows, while the second study investigated calorie shifting within the same time frame. Additionally, the effects of skipping breakfast entirely, which have been associated with reduced total daily energy intake and weight loss, were not explored in these studies.

What Happens When You Try Intermittent Fasting for 30 Days?

Practical Recommendations: Based on the available evidence, two main strategies can be considered for managing the timing of energy intake:

1. Narrowing the Feeding Window: Restricting the duration of the daily feeding window can indirectly reduce hunger and energy intake. Even moderately restricted feeding windows, such as 8-10 hours, have been shown to be effective.
2. Temporal Positioning of the Feeding Window: While there may be a slight advantage to consuming calories earlier in the day, the overall impact appears to be smaller compared to the width of the feeding window. Therefore, if you prefer a later feeding window and are satisfied with your current diet, there is no need to worry about changing it. However, if you struggle with hunger or aim to promote weight loss, adjusting food choices and narrowing the feeding window to 8-10 hours per day can be effective.

In conclusion, the timing of meals can influence metabolism and appetite, but the effects of late-night eating on weight loss and overall energy expenditure seem to be relatively small when compared to other factors such as the duration of the feeding window. While late eating may lead to a lower metabolic rate and increased hunger, it is important to consider overall energy intake and individual preferences when designing an eating pattern. Narrowing the feeding window and distributing calories evenly throughout the day are potential strategies to manage appetite and promote weight loss. As always, consulting with a healthcare professional or registered dietitian can provide personalized guidance based on individual needs and goals.

Further Your Knowledge: New Research Findings On the Best Fasting Length for Fat Loss (12 vs 36 vs 72 Hours)