Dehydration causes your body to retain excess water, which can lead to 5 pounds of weight gain overnight (5). When you feel thirsty and drink a lot of fluid at once, you'll absorb the extra fluid quickly and it shows up on the scale within 24 hours.
What's happening? Daily weight fluctuation is normal. The average adult's weight fluctuates up to 5 or 6 pounds per day. It all comes down to what and when you eat, drink, exercise, and even sleep.
They can be caused by many different factors: eating a large meal, excess salt intake, water retention, constipation, varicose veins and hormonal changes. The increase on the scale does not always equate to an increase in body fat. True weight gain is a process that happens over time, not overnight.
Fast facts on water weight:
Water levels can make a person's weight fluctuate by as much as 2 to 4 pounds in a single day. Severe water retention can be a symptom of heart or kidney disease. More often, it is temporary and goes away on its own or with some simple lifestyle changes.
Keep in mind that it's virtually impossible to gain weight after one large meal. If you get on the scale and see your number go up, it's simply because your blood volume level has increased due to the large quantity of food that you've eaten.
You're Dehydrated
Dehydration causes your body to retain excess water, which can lead to 5 pounds of weight gain overnight (5). When you feel thirsty and drink a lot of fluid at once, you'll absorb the extra fluid quickly and it shows up on the scale within 24 hours.
But you didn't actually gain five pounds of fat in a single day. After all, gaining a single pound of fat requires consuming about 3,500 calories more than you can burn off. So to gain five pounds in a day, you'd have to eat nearly 20,000 calories in just 24 hours.
If you push on your skin with your finger or thumb and your skin remains depressed, you're probably experiencing water retention. Fat cells are more springy, so the skin will bounce back.
Unintentional weight gain occurs when you put on weight without increasing your consumption of food or liquid and without decreasing your activity. This occurs when you're not trying to gain weight. It's often due to fluid retention, abnormal growths, constipation, or pregnancy.
Dehydration and Weight Loss
Hypohydration (low water intake) can also lead to increased body weight. In addition, dehydration decreases your metabolic flexibility (how well you utilise lipids and carbohydrates) which leads to weight gain.
The length of time that it takes to lose water weight depends on how much water you're retaining, the cause of the water weight gain, and the action taken to lose it. If you have one high-sodium meal and then return to normal, healthy dietary habits, you'll likely return to your normal weight in 1-2 days.
A person can't actually gain or lose multiple pounds of body fat or muscle in a day, but it is possible to retain or shed a few pounds of liquid. Diet — especially salt consumption — plays a major role in how much water our bodies hold onto throughout the day.
Since many people can't eat enough in a day or two to actually gain 5 or 10 pounds, if you notice a dramatic increase on the scale, chances are it's due to water, says Anita Petruzzelli, M.D., owner and medical director of BodyLogicMD.
You ate your last meal later than usual
If you pushed dinner back later than normal, you might be seeing food mass on the scale the next morning. And if you keep a regular schedule, you're likely accustomed to weighing yourself at a specific point in your digestion.
Drinking Water Can Make You Burn More Calories
Drinking water increases the amount of calories you burn, which is known as resting energy expenditure ( 4 ). In adults, resting energy expenditure has been shown to increase by 24–30% within 10 minutes of drinking water.
In addition to an oily appearance, your urine might also have a milky white color. This is due to the presence of fat and protein in lymph fluid.
Water weight gain occurs when extra water is stored in the tissue or between blood vessels. There are a number of factors that can cause water retention including consuming high amounts of sodium or carbohydrates, dehydration, lifestyle, hormones, medication, or even the weather.
The Role of Glycogen
You may end up weighing more in the morning simply because your muscles are storing more glycogen. The same phenomenon happens in the opposite direction when eating low-carb. You can drive your muscle glycogen fairly low by eating a low-carb diet.
It can be useful to remember that, just as one day of dieting will not cause a person to lose weight, a day of binge eating will not cause weight gain. Although an episode of overeating can happen to anyone occasionally, some people have a binge eating disorder, which usually requires professional attention.