Why Does My Weight Increase At Night?

Watching your weight is an interesting part of weight management. When you are trying out various ways to lose weight you are also more curious to know what factors affect your weight and how. As your body weight changes during the day and night and is influenced by diet, sleep, hormones, and other factors, you can see certain variations in your weight.¹ Why does my weight increase at night? This is a common question that needs understanding about factors affecting your weight in detail.

It is believed that weight watching can be an effective way to keep up with weight loss motivation. But with the fluctuations in weight throughout the day you want to ensure your weight changes are accurately recorded. Although it can be useful in determining the amount of weight loss, it can also be misleading at times. The main reason is that during the day and throughout the night, many factors are playing an important role in the physiological processes. Similarly, every person has their constitution and predisposition or risk factors for certain conditions, some existing health conditions, and treatment methods. All these factors influence your weight and can contribute to weight increase at night.

So, if you are wondering why my weight increases at night, you are not the only one and this may be just normal. Depending on your body constitution weight fluctuations vary. People with more muscle mass may experience weight changes differently than those with more fat. Similarly, your diet, activity levels, sleep duration, and quality influence your weight to a great extent. Let us look at these factors in detail.

You must be aware that adequate sleep is necessary for relaxation, rejuvenation, and healing of your mind and body. But that is not all. Sleep has a much greater role to play in your weight management too. Recent studies suggest that inadequate sleep can trigger certain processes in the brain that can result in increased appetite, promote more consumption of food and result in overeating.² It is also noted that short sleep duration can activate the neurohormonal response and increase abdominal adiposity.²

While these changes can affect more in the longer run, these can also show regular fluctuations, hence sufficient sleep is advised not only for good health but also for an ideal weight.

The main reason why sleep can affect your appetite and weight is that hormones and neurotransmitters secreted during sleep regulate these functions. In a study, it was observed that men who slept for four hours had greater levels of ghrelin and reduced leptin as compared to those who slept for ten hours.³ This imbalance of these two neurotransmitters can influence your appetite, food choices, metabolism, and weight gain at night.

An interesting conclusion given by a 2008 study suggests that average sleep is the best thing to have. The 6 -year-long study showed that both short-duration, as well as long-duration sleeping, was associated with a greater risk of body weight and fat gain in adults as compared to those with average sleep duration.⁴

When considering why your weight increases it is important to consider your sleep health. Certain factors related to sleep health also include sleep quality, sleep timings, sleep patterns, and regularity of sleep. Studies have concluded that sleep restrictions can result in increased energy intake, reduced glucose tolerance, and also increase risk of obesity.⁵

Similarly, late sleep timings can increase the risk of post-dinner caloric intake and reduced physical activity.⁵ Sleep disorders that affect the quality of sleep, like obstructive sleep apnea (OSA), should also be considered. A 2021 study concluded that better sleep health was associated with greater weight and fat loss and the associations were attenuated after accounting for the severity of obstructive sleep apnea.⁵

Thus, it can be concluded that sleep is a crucial modulator of neurohormonal function, glucose metabolism, and increased risk of obesity.¹ In daily variations, sleep can affect your glucose tolerance, evening concentrations of cortisol, imbalance of ghrelin and leptin, and increase appetite. These factors can thus play a major role in causing an increase in your weight at night.

Diet has always been an important factor affecting your weight but it can also be particularly responsible for the increase in your weight at night. Nighttime eating or what you have for your dinner is a crucial factor again. A heavy meal, calorie-dense foods, junk snacks, or late-night munching can have an impact on your weight. This is one of the main causes of the increase in weight at night.

Experts have been advising to limit the food intake at night or avoid food before bedtime, as a weight loss strategy or for a healthy lifestyle. However, consuming nutrient-rich, low-calorie foods may be more beneficial for maintaining health and managing weight. Some also suggest having single nutrient foods or protein-rich foods. Also keep in mind that people with diabetes need to have meals at regular times, hence proper, nutritious diet planning is a must. Some studies have also shown that the addition of exercise training for four weeks can help eliminate adverse effects of nighttime feeding apart from improving cardiovascular health.⁶

Various physiological processes affect your body weight at night, which not only includes the amount of food but also its absorption and metabolism. How various hormones play a role in the digestion of food, or the regulation of other bodily processes influences your body weight at night. Certain conditions related to hormones or other medical conditions can result in water retention that too can cause an increase in your weight at night. In women, the menstrual phase plays a very important role as many women may experience bloating, and weight gain before or during their periods, and both seem interlinked. In a 2017 study, the results indicated that greater changes in body weight were associated with greater chances of menstrual irregularity.⁷

In some cases, certain medications that you are taking too can influence your weight at night. It is possible that some medications like neurotropic drugs, corticosteroids, and anti-psychotic drugs, can increase the risk of weight gain in susceptible patients.⁸

It is essential that you follow a healthy diet and lifestyle, and follow up with your doctor regularly for your existing medical concerns and any ongoing treatment.

While there is no specific time to weigh yourself, it is ideal to maintain the same pattern. You can plan to check your weight once a week, preferably in the morning on an empty stomach, and after you have finished with your morning rituals, in the same type of clothing.

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