A 2012 study at Oxford University found that the fat in your food ends up on your waistline in less than four hours. Carbohydrate and protein take a little longer, because they need to be converted into fat in the liver first and it takes nine calories of protein or carbohydrate to make 1g of fat.
Your rate of weight gain will depend on a number of factors, including your body size, sex, calorie intake, genetics, activity level, and health status. Increasing your calories by about 500 beyond your daily maintenance calorie needs could allow you to gain about 15 pounds (6.8 kg) over 6 months.
So here it is: If you live an entire week avoiding nutrition labels and making gym excuses, you can expect to gain about four pounds—one to two pounds of water weight (bloating) and one to two pounds of actual fat, Glassman says.
For some people, the first noticeable change may be at the waistline. For others, the breasts or face are the first to show change. Where you gain or lose weight first is likely to change as you get older. Both middle-aged men and postmenopausal women tend to store weight around their midsections.
You Ate a Big Meal Recently
It's just downright mean to weigh yourself after you just ate a big meal. According to the Mayo Clinic, food can take up to eight hours to pass through your digestive system, which can cause you to retain a little extra weight until the process has ended.
The good news is that you can't just gain 3kg of fat in 3 days. There are plenty of ways that your weight can fluctuate that aren't to do with your fat mass. Here are a few of the most common causes of sudden weight gain.
Healthy weight gain of 1-2 pounds per week can be expected when reasonably increasing energy intake. It takes an excess of about 2,000 to 2,500 calories per week to support the gain of a pound of lean muscle and about 3,500 calories per week to gain a pound of fat.
Healthy weight gain is about 1 to 2 pounds per week. If you're not a weight lifter, you can gain about 2 to 4 pounds (0.91 to 1.81 kg) of both muscle and fat weight a month.
The balance between energy in (eating) and energy out (burning off those calories) is why your weight goes up and down. If you take in more than you burn, you gain weight -- sometimes right away.
And it turns out, you'd have to take in a ridiculous amount of food to gain even just a pound in one day. “It's virtually impossible to gain weight overnight, even if you really blew it on bar food,” says Cassetty. “The reason comes down to calorie math.
Bloating may occasionally add a pound or two, but it doesn't actually signify weight gain. A simple way to tell the difference between bloating and weight gain or fat is how your stomach looks and feels. If your stomach is tight and hard, then bloating is the cause. If your stomach is soft and thick, then that's fat.
After a weekend of consuming junk foods or foods containing simple carbs, your body will retain water. The high sodium and carbohydrate content causes an increase in fluid retention in the body. And that's why you feel bloated and bulky. It's nearly all extra water weight, and not actual body fat that you have gained.
It's absolutely possible to gain 3, 5 even 10 pounds overnight, but don't worry! It's not fat and it's totally temporary. There are 7 possible reasons why you gained weight and I'll break them down for you below.
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.
Try smoothies and shakes.
Avoid beverages with few nutrients or calories, such as diet soda. But a blend of high-calorie, nutritious ingredients in a smoothie or shake can help if you're eating on the go. Meal replacement drinks also may be part of your weight-gain effort.
Try almonds, sunflower seeds, fruit, or whole-grain, wheat toast. Go nutrient dense. Instead of eating empty calories and junk food, eat foods that are rich in nutrients. Consider high-protein meats, which can help you to build muscle.
Healthy Rate of Weight Gain
A more reasonable rate of weight gain is 1/2 to 1 pound weekly, or 2 to 4 pounds per month.
D., who has conducted many of these studies at McMaster University in Ontario, says he expects the average subject to gain 4 to 7 pounds of muscle in three months. No matter how good the program or supplements are, he never sees average gains exceeding about a half-pound a week.