Not necessarily. Your body will try to take that pound of food and use it for energy. Your body gains and loses weight based on its metabollic rate, or the number of calories it uses on a daily basis. Your body naturally burns calories throughout the day, no matter what you are doing, but you will gain weight if you take in more calories than your body is burning. That's why exercising is so helpful. Most of us spend 8 hours/day or more behind a desk but eat like we're active all day. By exercising, we burn those extra calories and boost our metabollic rate, helping our bodies to keep the natural calorie burning going. So no, you won't gain a pound if you eat a pound of food,but you will gain a pound if your body can't burn off those excess calories. ...and just to set the record straight, I didn't answer my own question, notmrjon. I am anonymous and whoever rated my answer was anonymous too..thanks though.

In addition to the metabolism, there are other factors even more important. In general, around 3500 calories are needed to create 1 pound of body fat. Since the number of calories per pound of food vary greatly, it would depend on what you eat. Some common food labels can be seen at http://www.calorie-count.com/calories/item/19335.html. Sugar is listed as having 774 calories for 200 grams. 454 grams per pound so sugar has 1756 calories per pound. Sugar would never produce a pound. Lard has 1849 for 205 grams (4094 calories per pound) which is possible to gain a pound for a pound. Lettuce has 2 calories for 10 grams (91 calories per pound). At least 39 pounds of lettuce would be needed.

I can,t resist that fact that adding a pound to something is just that. At breakfast that pound might never give you that pound gain but maybe by dinner time you have eaten enough to where the body will not burn it or pass it through slowly and the scale shows a pound. But during the day a pound of weight gain or loss is normal. But eating a extra ounce a day will be a extra pound a month and after few months it might be noticed. Probably after a year 12 pounds might stand out. I going to assume that a pound of weight gain is a issue that you would be concerned about it looks. Otherwise who cares about weight if one looked the same at any weight. There are cases of gaining weight and looking better. If you start exercising, fat is traded out pound per pound to muscle. Muscle is dense and is two to three time smaller than fat when they are the same weight. So you could possibly get heavier and look lighter. But daily weight can take on a pound with a couple of glasses of water but and extra ounce of food that you can,t burn daily will put you fifty pounds overweight in four to five years. What is worse is if one decides to loose that, it take the same time to get where you started and stay there. Done any faster will only be a temporary fix. Weight gain is one of the few things that comes easy and goes hard (easy come and easy go is not the case). If you eat one pound of extra food over a month, you will gain a pound for good until you do the opposite. Not stop but deprive yourself of a pound a month. I call is "deprived" because I don,t think walking away from a meal slightly hungry is satisfying meal.

A 16 oz. volume of water, weighs about a pound. If you weigh yourself before and after you drink 16oz. of water, you will weigh about one pound more after you drink the water. But, if you wait about 10 hours before weighing yourself, you will be about the same weight. Assuming you don't consume anything else. Water has zero calories. But the water itself has weight. If you dump a bunch of sugar in the water and do the above exercise, you could actually weigh more after the 10 hour wait. The excess calories that are not used are stored as fat. I foresee a science fair project coming on. It's sometimes simpler to think of weight gain or loss as a balanced equation. If the calories in equals the calories used, no change in weight. If the average person doesn't eat or drink for 24 hours, they will weigh between two to threee pounds less. There are several variables here so it gets a little complicated. If you continue your starvation diet, you will die from dehydration before dying from malnutrition.

No, and for the following reasons. 1.Not all the food eaten are absorbed in the stomach and small intestines. Cellulose for example can not be digested by humans. 2.Most of the absorbed nutrients (carbohydrates) are used by the muscles and other organs for energy production via ATP.The proteins are used for cell repair, cell replacement (eg. cells of the skin and mucus membranes of the intestines). It is also used to synthesise hormones, mucus, saliva and other substances secreted and eventualy excreted . Only the exessive nutrients are converted into fat and stored in the bodie's fat depots for later use.

I would say yes -- until it is digested, utilized as fuel, passed as waste -- or most likely some combination of. All of that begins almost immediately.