The bottom line. It's totally normal for our weight to go up and down. This can happen because of the food we eat, how much water our body holds or even how active we are.
A lot of people wonder why they weigh more at night. The reason is because you carry more water weight at night. When you're awake, your body's sympathetic nervous system is active and releases adrenaline and cortisol. These hormones cause your muscles to contract, which uses up water and increases your weight.
It may be water weight gain, because everyone gains water weight trough out the day no matter what. And then the next day, you're back to your normal weight or you've lost a little water weight.
Daily weight changes are expected, usually between 2 to 4 pounds in either direction. Water retention, digestion, exercise, temperature, hormones, medications, and illness can cause these changes. Knowing what's typical can help you spot changes that might need attention.
It's common for your weight to fluctuate within a 5-pound range. But if you've gained weight “overnight” and feel bloated, it might be from retaining water because of: Eating high-sodium foods.
Fluid retention
It's totally normal for your weight to change up to four pounds in a single day, based on your fluid levels. Fluid retention, or edema, is when a lot of fluid builds up in the body. This can cause a sudden weight gain of 15 or more pounds.
You should step on the scale first thing in the morning. That's when you'll get your most accurate weight because your body has had the overnight hours to digest and process whatever you ate and drank the day before. And you should try to turn that step into a regular part of your routine.
Weight gain and short-term fluctuations may happen for a variety of reasons, such as aging or making lifestyle and dietary changes. However, fast weight gain can be a sign of an underlying health condition, such as a problem with the thyroid, kidneys, or heart.
How Much Weight Is Lost Overnight. Ever step on the scale in the morning and think, “Where'd those pounds go?” Well, you can drop about 1 to 3 pounds overnight, but hold on, most of that is just water taking a hike—not fat. As Healthline mentions, water loss accounts for over 80% of this mysterious vanishing act.
So even though you may be losing fat, you're gaining muscle. You might feel slimmer, even as the number on the scale rises. “The scale doesn't tell the entire story,” said exercise physiologist Christopher Mohr, PhD, RD. “Since muscle and fat take up different volume, they look very different on the body.”
Drinking Too Much Water
A quart of it weighs about 2 pounds. If you just drink it -- and you don't exercise -- that'll show up on the scale right away. That doesn't mean you should give up H2O. In the long run, drinking water (especially instead of high-calorie sugary beverages) can help you lose weight.
Aim to weigh yourself on the same day, at the same time and in the same environment each week – for example, first thing every Friday morning when you're getting ready to take a shower, after you've gone to the bathroom, but before you've drunk or eaten anything.
Endocrinologist Kathleen Wyne, MD, says that a five-pound weight shift is typical for most people day-to-day but that the number on the scale can change by as much as 20 pounds depending on your body size.
“Your skin is the largest organ in the body and absorbs fluid easily,” says Dr. Keith Kantor, a leading nutritionist and CEO of the Nutritional Addiction Mitigation Eating and Drinking (NAMED) program. “After a swim or a shower, your body can absorb 1 to 3 cups of water, increasing your true weight by a few pounds.”
Your Weight Can Fluctuate Throughout the Day
This is due to factors such as hydration levels, the food you've consumed, and even your bowel movements. Therefore, it's recommended that you weigh yourself at the same time each day, ideally in the morning before breakfast, to get a consistent measurement.
It's mostly water weight. There are many factors when it comes to your body holding onto more weight. Your body can fluctuate in weight every single day, many pounds. It's not pure fat as you can't gain multiple pounds of fat overnight.
Hormonal belly is when a person gains weight around the abdomen due to hormonal fluctuations. This could be due to changes in thyroid, adrenal, reproductive, or other hormone levels.
If you're asking yourself, “Why am I gaining weight when I barely eat,” several factors may be at play. Your body may be holding onto fat stores if your eating habits are inconsistent or restricted. Or, your weight gain may be the effect of a sedentary lifestyle, medical condition, or long-term stress.
Water weight is not usually a cause for concern, but it can be uncomfortable and recurring. Reducing salt and carbohydrate intake, keeping hydrated, and frequently exercising are all good ways to lose water weight and prevent it from returning.
So if you notice you do weigh more at night, that's normal: Body weight is typically a bit lower in the morning because you eat less food and fluids overnight and lose water through sweat and breathing, per the American Physiological Society.
Most experts recommend aiming for 1-2 pounds of weight loss per week, which equates to roughly 4-8 pounds in a month. Those with more excess weight may see slightly faster loss initially. The key is losing at a gradual rate through calorie deficit rather than drastic measures.
People tend to weigh less when they wake up because breathing and sweating as they sleep causes them to lose fluids. A study also found that adults burn around 50 calories an hour during slumber.