How many unused calories is what's important here. Remember that you're burning calories just sitting around- about 80 an hour or so. You burn at least 1000 calories in a day just breathing, thinking and so on.
A pound of fat contains roughly 4082 calories. So you'd have to consume 4082 calories beyond what you burn in a day to gain a pound of fat. Conversely, you'd need to burn 4082 calories more than you consume to lose a pound of fat. That may seem like a lot, but realize that an extra hundred calories a day, everyday, over the course of a lifetime can really add up, a pound a month, 12 pounds a year.
A pound is equivalant to 453.592 grams, and 1 gram of fat is equal to 9 calories. Therefore 453.592 grams per pound*9 calories per gram of fat= 4082.328 calories per pound. But in all reality all of those calories wouldn't be stored as fat. They could be stored as protein or carbohydrates, which both contain 4 calories per gram, so plug in four instead and you get 1814.368 calories per pound. So calories needed to gain a pound are 1814.368 to 4082.328 calories.
There are about 3,500 calories in a pound. Burn 3,500 calories more than you take in = loose one pound. Take in 3,500 more calories than you burn = gain a pound.
To gain 1 pound a week, 500 calories added to your usual day would do it.
3500 calories
It would take 7 weeks. Though when trying to gain weight the same principles tend to apply as losing it. I.E. Try to gain about a pound a week.
3500
In general, to gain 1 lb of body fat you need to create a calorie surplus of 3500 Calories. For example, if you intake 2500 calories a day and expend 2000, that's a surplus of 500 calories a day. At that rate you will gain 1 pound a week (7 days x 500calories/day = 3500 Calories) You need to consider your natural body metabolism and how much you exercise, and compare that to how much you eat.
3500 calories equal a pound, so if you burn 200 calories a day it will take approximately 18 days to lose a pound, assuming you're burning 200 more calories than you take in.
It take about 3500 calories to burn 1 pound of fat. So that would mean that if you lower you caloric intake by 500 calories in a week you would lose about 1 pound.
weight is measured by calories, not time.
If you take in more calories than you burn, you will gain weight. It does not matter what the extra calories are composed of, 3500 calories is a pound. Protein contains 4 calories per gram, Carbohydrates contain 4 calories per gram, and Fat contains 9 calories per gram.
Not exactly. It takes 3,500 extra calories (that you do not burn off) to gain one solid pound of weight. If you eat that many calories, which is probably a considerable amount of food, you will "gain" weight quickly. But most of that is the food and drinks still in your body. That will naturally go down in a day or two as it passes through and out of your body. Also, it does take energy (burning calories) to digest foods, too.
It depends on her age, height, and many other factors.