General Question

mary2's avatar

How come you can gain more than a pound of weight by eating less than a pound of food?

Asked by mary2 (82points) October 18th, 2008

Where does the extra weight come from?

Observing members: 0 Composing members: 0

29 Answers

mea05key's avatar

it is due to the food nutrient value such as carbohidrates, fats, protein etc. The body processes carbohidrates and protein into fats when they are not not used.

mary2's avatar

What? That doesn’t make any sense.

If I eat 3 quarter-pounders (just the meat, no bun or fries or anything). I have consumed .75 pounds of food. If I weighted 110 pounds before I eat, I should weight 110.75 pounds after I eat (and even less after I poo), in theory.

Of course, if I actually did eat 3 quarter-pounders, I’d gain more than 1 pound. Where does that extra weight come from?

peziak's avatar

It’s not the weight of the food you consume but the amount of calories it contains.

Weight gain really depends on your caloric intake. You can eat a small lasagna for lunch and that lasagna alone has between 400–600 calories. That lasagna is chocked full of calories because it contains a lot of fat. 1 gram of fat=9 calories, where as 1gram/protein/carbs=4calories. 3600 calories produces a lb of weight. Calories can be like the big gift in an otherwise small package.

That’s why they suggest that an adult eat 1200 cals per day because the assumption is that you will offset that caloric intake through some level of physical activity.

nikipedia's avatar

That is a great question.

A pound of fat is 3500 calories. So if you found food that was more calorie-dense than your pound—say, something that delivered 5000 calories per pound—then you could gain more than a pound by eating less than a pound. If each quarter-pounder has 1200 calories, then eating three of them would yield 3600 calories—a little over a pound of fat.

Also, if you eat a quarter-pounder with fries, you are eating an awful lot of salt, and your body will retain a great deal of water to balance out that salt intake. So a lot of the immediate weight gain is probably not actual fat, but water retention. The fat comes later. :)

mea05key's avatar

peziak and nikipedia explaination is awesome

augustlan's avatar

Just FYI, the quarter pounder does not weigh a quarter pound after it’s cooked…that is it’s pre-cooked weight.

La_chica_gomela's avatar

Peziak, great explanation!

I just have one issue with your answer: the phrase, “That’s why they suggest that an adult eat 1200 cals per day”

I’m not sure who the “they” you’re referring to is that recommends the average adult eat 1200 calories per day, but the Food and Drug Administration actually recommends 2000 calories. You can verify this by looking at the “Nutrition Facts” on the side of any package of processed food. Somewhere in that box will be the words, ”*Percent Daiy Values (DV) are based on a 2,000 calorie diet.” In fact, I copied that off of a package of chewing gum that’s on my desk.

On the other hand, experts are trying to get away from one standard recommendation for an “average American” or “average adult” since each person is different. The Food Pyramid website does not even list one recommendation, it just asks you to input your own information, height, weight, etc, and then gives you a personalized recommendation, so the issue is almost a mute point.

stratman37's avatar

Conversely, you can actually LOSE weight by eating celery. You burn up more calories in the process of chewing and digesting, than the stalk contains.

Zaku's avatar

On the short-term, though, your weight really is starting weight plus stuff in minus stuff out, but stuff in includes drinking and stuff out includes perspiration. Most body weight is water, and many foods cause water retention.

For example, if you weight yourself and then eat half a pound of celery, your weight will increase by half a pound. If you then eat half a pound of ice cream, your weight will increase by another half a pound. That’s the immediate and only really measurable effect on your weight, until you start to consume or excrete something else. They will both affect your energy, nutrition, digestion and appetite for other things rather differently, though.

funkdaddy's avatar

Someone correct me if I’m wrong but if you eat a pound of food, you will gain that pound until you drop some of it off as waste. It’s not possible to gain more than a pound from a pound put in.

Even if you eat one pound of pure fat (which would have the greatest density in relation to calories) if that was a perfect transfer into weight on your body, (which it’s not) you would only gain a pound. More realistically, you will burn some of that pound, pass some of it as waste, and then store a small portion on your frame if you have calories left over.

You will never be able to gain more than a pound from a pound of food. Your perception when dieting is that a big meal will ruin all your hard work, but truly as long as you run a slight deficiency, over time you will lose weight.

La_chica_gomela's avatar

Funkdaddy, I would tend to agree with you.

I was under the impression that there existed something called, “The Law of Conservation of Mass”. References are made to it in many science textbooks. In fact, it’s sort of one of the the cornerstones of all chemistry and physics. It says something along the lines of “Mass cannot be created nor destroyed”. Maybe some of you have heard of it?

This would indicate that if a person ingested, say 1 lb of food, it is not possible for more than 1 lb to be added to the person’s body weight. That would be a creation of mass, i.e. an impossibility, according to the law of conservation of mass.

nikipedia's avatar

@Lcg: The energy is conserved, not the weight. Consider the celery/ice cream example. (Calories are measurements of energy.)

La_chica_gomela's avatar

Niki, I’m not saying that a person would gain exactly 1/2 a pound if they ate exactly 1/2 a pound of… potato chips or whatever. I’m saying that…they couldn’t gain more than 1/2 of pound. Are you saying they could?

Zaku's avatar

I thought I just answered that. ? ;-) ?

It works the way your intuition should tell you it works. There is both conservation of mass and of energy (and e=mc^2, though c is a BIG number, so energy use is not going to just dematerialize and radiate much food mass), so in the short-term, it’s conservation of mass, but in the long-term, your body is a chemical machine that keeps taking in and excreting material, and that’s where the difference comes in between types of food, because your body will keep the yummy stuff and have you get thirsty, and it will expel the celery along with the waste the celery helps scrape off, and you’ll breathe and sweat and get hungry and thirsty and pee and poop and all that stuff in response to what you eat, which adds up to the long-term effect. But short-term, it’s just conservation of mass.

Zaku's avatar

La chica, you’re right, except you will want to drink a bunch of water after eating those, and even if you don’t your body will want to pee (and perspire) much less than if you hadn’t eaten them, and most of your body mass is water.

La_chica_gomela's avatar

Zaku, thanks for answering my question (and the querent’s underlying question).

as far as the potato chips are concerned, i don’t eat them, and i am quite familiar with the effects of sodium on the human body. ;-)

No one on this thread except Funkdaddy and me seemed to be trying to dispel the assumption that you could gain more than what you had consumed.

Lightlyseared's avatar

@stratman I’m afraid the celery thing is a myth.

MissAnthrope's avatar

I’m majorly confused on where this thread is going. We’re talking long-term weight, right?

You can eat a pound of food and for the next couple of hours, you would weigh a pound more. After that, your body breaks down the food and begins to disseminate it. Water is extracted, fats, salts, etc. You pee out some of the water. The fats get stored. You eventually, uh, pass the meal you ate. In the short term, that pound you ate is gone.. it’s been broken down and a good deal of it is excreted as waste.

Theoretically, at least, it’s absolutely possible to eat less than a pound of food and gain a pound, depending on what it is you’re eating and how slow or fast your metabolism is. There is a huge difference between foods. Some are extremely dense in fat and calories (cheesecake) and others have little to none (celery, lettuce). The calories and fat in a single piece of cheesecake are so much that you’d have to eat pounds and pounds of celery/lettuce to get the same weight/caloric effect.

If your food is nutritionally dense like cheesecake, you could eat a meal of McDonald’s and a piece of cheesecake and be well on your way to gaining that pound.

Double Quarter Pounder w/Cheese: 740 cal, 42 g fat
Large Fries: 500 cal, 25 g fat
Ketchup for those fries: 15 cal per packet (we’ll say 3 packets for the large fries)
Commercially prepared cheesecake: 257 cal, 18 g fat

Total: 1542 cal, 85 g fat

Now, 1542 calories is about half a pound, but add in probably a soda to drink, as well as all that fat and that number goes up even more. Numerically, you’re getting awfully close to that added pound of weight. As I mentioned, factors such as metabolism and physical activity can affect how much is actually stored.

nikipedia's avatar

@Lcg: I’m only speculating here, but the way I understand it rests on density. Your pound of fat is not 100% pure calories just like the food you eat is not 100% pure calories. So when your pound of fat is stored, there’s probably a lot of water and other, non-ATP related molecules hanging out in there. So for instance, if you were to imagine a hypothetical square micrometer of calorie-dense food and a hypothetical square micrometer of fat (this is for the sake of argument; I do not mean to suggest this is what adipose tissue actually looks like):

(29 calories)

(29 calories)

So the adipose tissue could end up weighing more than the initial energetic investment because it is not a strict calories—>fat conversion. The pound on your body must be full of other stuff (water, electrolytes, cell organelles, whatever).

Again, just a guess.

La_chica_gomela's avatar

Niki, fat / adipose tissue is actually one of the most highly efficient methods of storing calories that exists.

Even if you’re talking about eating pure lard, I can’t imagine a scenario in which stored body-fat would weigh more than the food eaten.

Okay, there is one situation I can think of where you might weigh more, but only temporarily. The bodies of athletes tend to store more glycogen than other people, and glycogen is a rather “heavy” calorie storage method (because it includes a lot of water), but it is very easy to convert to ATP. I’m still trying to work out in my head how this might happen, but if there is a scenario in which a person could gain more weight than they ate, I would wager it involves glycogen.

funkdaddy's avatar

I think there are two conversations going on here

1) can you eat a pound of something and immediately gain more than a pound (which I believe everyone agrees is just not possible)
2) If you eat a pound of certain foods, it will it add more than a pound to your overall “long term” weight

I don’t see how #2 can be possible either.

It’s been a while since I’ve been in a biology class but I seem to remember the rule of thumb we were giving is that 10 pounds of eat-ee gets you one pound of eat-er (advanced scientific terminology there), this was used whether you’re feeding hay to cows, plankton to krill, or buffalo to wolves (see Food Chain)

I believe the theoretical 3500 calorie pound of fat in the body must already take into account the tissue that doesn’t contribute calories because this would be significantly less than a theoretical “perfect” pound of fat (a pound is ~453 grams, 9 calories per gram = ~4100 calories).

So if we can assume for the sake of argument that
1) the MOST calories you can get out of a pound of food is 4100 – which is a great stretch, I don’t even think drinking olive oil straight would get ya there
2) The leftovers will be stored as fat (muscle, organs, and other tissues are going to take a lot more energy to build)
3) At least 80% of those calories are going to be burned, passed, or wasted in some way (generally this is 90%, doubling the retained portion for arguments sake)
4) We’d need ~3500 calories left over to build a pound

4100 – 80% = 820 calories left or about 91 grams of fat on your body. You would need to store three times the weight of the actual fat in water and other goodies to gain your pound from eating an ultra dense brick of fat. I just don’t believe it’s going to happen.

Even if your metabolism is extremely slow I don’t believe you could pass food and retain 50% of the calories, which would still mean about half the weight gained from the densest pound possible would need to come from sources outside the actual meal.

I’d love to be proven wrong if someone sees holes in the assumptions, I find this stuff interesting.

Also, I think the most interesting thing is the (apparently widely held) perception that four quarter pound patties are going to make you balloon up when really I think it’s just having an excess of calories each day that contributes to weight gain.

Lightlyseared's avatar

@stratman well done for finding an Internet page to support your claim that doesn’t change the fact you’re wrong. Firstly there has been no research to support this claim and secondly the metabolism and physiology of digetion has been well studied.

The body expends about 225 calories a day on digesting 1500 calories. It doesn’t matter where those calories come from the figure doesn’t change. If you got all 1500 calories from celery you would still only burn 225 digesting it.

stratman37's avatar

After looking around some more, I’m finding that the jury is still out on the answer. I thought was a reputable site, they do their research and all.

Noel_S_Leitmotiv's avatar

Its fluid retention.

Carbohydrates, salt, and allergens in your food cause your body to retain water.

Water has considerable weight.

Nullo's avatar

They’re mostly reputable, though they do show signs of bias from time to time. Not usually with regards to food :\.

milln009's avatar

Ok I am trying to wrap my head around all of your concepts about a pound weighing 3500 calories. A Calorie is a unit of energy, not mass. So any reference to Calories to prove your point is mute. You are saying that a pound of fat can weigh more then a pound of lettuce because the fat has more calories. Now actually reread that and hit yourself in the forehead. If you eat a pound of food, a pound will be added onto your body weight. If you have ever wrestled you will know this to be a complete proven fact. Oh yeah by the way, water has no calories so try explaining to me how if you drink 16 ounces of water you gain exactly one pound. (16 ounces is equal to one pound). Thank you for your time.

Pandora's avatar

I don’t think it is always food that determines how much you weigh. I think muscle density can have something to do with it. People on diets may be exercising and putting on more muscles. Fat is lighter than muscles. Second if you weigh yourself in the morning and then at night you will find a weight difference because you have been eating and drinking throughout the day. You will usually weigh less in the morning because your body continues to make waste and your not filling up as you sleep. ( We sweat as we sleep and lose water as we breath as well.) Most of us also pee before bed.
Another reason for gaining a pound in a day may simply be water retention or if your scale doesn’t read ounces it will round up or down according to your ounces. Let’s say. Yesterday you actually weighed 125.4 but your scale only shows 125 than you weigh your self today and you drank some water and not you actually weigh 125.9 so the scale reads 126. So you think you put on a pound.
Or one day you are 125.4 but reading only 125 and the next day you are 126.5 and the scale rounds up to 127. Now you think you put on 2 lbs.

bizmo's avatar

It’s a tricky thing, like eating a pound cake a gaining ten pounds. Calories, calories, calories…

Answer this question




to answer.

This question is in the General Section. Responses must be helpful and on-topic.

Your answer will be saved while you login or join.

Have a question? Ask Fluther!

What do you know more about?
Knowledge Networking @ Fluther